Change imnodes to imgui-node-editor (more mature, more features)

16 files changed, 10834 insertions, 0 deletions

diff --git a/3rdparty/imgui-node-editor/CMakeLists.txt b/3rdparty/imgui-node-editor/CMakeLists.txt
new file mode 100644
index 0000000..2730a8e
--- /dev/null
+++ b/3rdparty/imgui-node-editor/CMakeLists.txt
@@ -0,0 +1,7 @@
+file(GLOB IMGUI_NODE_EDITOR_SOURCES *.cpp)
+
+add_library(imgui-node-editor ${IMGUI_NODE_EDITOR_SOURCES})
+target_include_directories(imgui-node-editor PRIVATE
+	${CMAKE_SOURCE_DIR}/3rdparty/imgui-node-editor
+	${CMAKE_SOURCE_DIR}/3rdparty/imgui
+)
diff --git a/3rdparty/imgui-node-editor/crude_json.cpp b/3rdparty/imgui-node-editor/crude_json.cpp
new file mode 100644
index 0000000..f2b3ba5
--- /dev/null
+++ b/3rdparty/imgui-node-editor/crude_json.cpp
@@ -0,0 +1,814 @@
+// Crude implementation of JSON value object and parser.
+//
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+# include "crude_json.h"
+# include <iomanip>
+# include <limits>
+# include <cstdlib>
+# include <clocale>
+# include <cmath>
+# include <cstring>
+
+
+namespace crude_json {
+
+value::value(value&& other)
+    : m_Type(other.m_Type)
+{
+    switch (m_Type)
+    {
+        case type_t::object:    construct(m_Storage, std::move( *object_ptr(other.m_Storage))); break;
+        case type_t::array:     construct(m_Storage, std::move(  *array_ptr(other.m_Storage))); break;
+        case type_t::string:    construct(m_Storage, std::move( *string_ptr(other.m_Storage))); break;
+        case type_t::boolean:   construct(m_Storage, std::move(*boolean_ptr(other.m_Storage))); break;
+        case type_t::number:    construct(m_Storage, std::move( *number_ptr(other.m_Storage))); break;
+        default: break;
+    }
+    destruct(other.m_Storage, other.m_Type);
+    other.m_Type = type_t::null;
+}
+
+value::value(const value& other)
+    : m_Type(other.m_Type)
+{
+    switch (m_Type)
+    {
+        case type_t::object:    construct(m_Storage,  *object_ptr(other.m_Storage)); break;
+        case type_t::array:     construct(m_Storage,   *array_ptr(other.m_Storage)); break;
+        case type_t::string:    construct(m_Storage,  *string_ptr(other.m_Storage)); break;
+        case type_t::boolean:   construct(m_Storage, *boolean_ptr(other.m_Storage)); break;
+        case type_t::number:    construct(m_Storage,  *number_ptr(other.m_Storage)); break;
+        default: break;
+    }
+}
+
+value& value::operator[](size_t index)
+{
+    if (is_null())
+        m_Type = construct(m_Storage, type_t::array);
+
+    if (is_array())
+    {
+        auto& v = *array_ptr(m_Storage);
+        if (index >= v.size())
+            v.insert(v.end(), index - v.size() + 1, value());
+
+        return v[index];
+    }
+
+    CRUDE_ASSERT(false && "operator[] on unsupported type");
+    std::terminate();
+}
+
+const value& value::operator[](size_t index) const
+{
+    if (is_array())
+        return (*array_ptr(m_Storage))[index];
+
+    CRUDE_ASSERT(false && "operator[] on unsupported type");
+    std::terminate();
+}
+
+value& value::operator[](const string& key)
+{
+    if (is_null())
+        m_Type = construct(m_Storage, type_t::object);
+
+    if (is_object())
+        return (*object_ptr(m_Storage))[key];
+
+    CRUDE_ASSERT(false && "operator[] on unsupported type");
+    std::terminate();
+}
+
+const value& value::operator[](const string& key) const
+{
+    if (is_object())
+    {
+        auto& o = *object_ptr(m_Storage);
+        auto it = o.find(key);
+        CRUDE_ASSERT(it != o.end());
+        return it->second;
+    }
+
+    CRUDE_ASSERT(false && "operator[] on unsupported type");
+    std::terminate();
+}
+
+bool value::contains(const string& key) const
+{
+    if (is_object())
+    {
+        auto& o = *object_ptr(m_Storage);
+        auto it = o.find(key);
+        return it != o.end();
+    }
+
+    return false;
+}
+
+void value::push_back(const value& value)
+{
+    if (is_null())
+        m_Type = construct(m_Storage, type_t::array);
+
+    if (is_array())
+    {
+        auto& v = *array_ptr(m_Storage);
+        v.push_back(value);
+    }
+    else
+    {
+        CRUDE_ASSERT(false && "operator[] on unsupported type");
+        std::terminate();
+    }
+}
+
+void value::push_back(value&& value)
+{
+    if (is_null())
+        m_Type = construct(m_Storage, type_t::array);
+
+    if (is_array())
+    {
+        auto& v = *array_ptr(m_Storage);
+        v.push_back(std::move(value));
+    }
+    else
+    {
+        CRUDE_ASSERT(false && "operator[] on unsupported type");
+        std::terminate();
+    }
+}
+
+void value::swap(value& other)
+{
+    using std::swap;
+
+    if (m_Type == other.m_Type)
+    {
+        switch (m_Type)
+        {
+            case type_t::object:    swap(*object_ptr(m_Storage),  *object_ptr(other.m_Storage));  break;
+            case type_t::array:     swap(*array_ptr(m_Storage),   *array_ptr(other.m_Storage));   break;
+            case type_t::string:    swap(*string_ptr(m_Storage),  *string_ptr(other.m_Storage));  break;
+            case type_t::boolean:   swap(*boolean_ptr(m_Storage), *boolean_ptr(other.m_Storage)); break;
+            case type_t::number:    swap(*number_ptr(m_Storage),  *number_ptr(other.m_Storage));  break;
+            default: break;
+        }
+    }
+    else
+    {
+        value tmp(std::move(other));
+        other.~value();
+        new (&other) value(std::move(*this));
+        this->~value();
+        new (this) value(std::move(tmp));
+    }
+}
+
+string value::dump(const int indent, const char indent_char) const
+{
+    dump_context_t context(indent, indent_char);
+
+    context.out.precision(std::numeric_limits<double>::max_digits10 + 1);
+    context.out << std::defaultfloat;
+
+    dump(context, 0);
+    return context.out.str();
+}
+
+void value::dump_context_t::write_indent(int level)
+{
+    if (indent <= 0 || level == 0)
+        return;
+
+    out.fill(indent_char);
+    out.width(indent * level);
+    out << indent_char;
+    out.width(0);
+}
+
+void value::dump_context_t::write_separator()
+{
+    if (indent < 0)
+        return;
+
+    out.put(' ');
+}
+
+void value::dump_context_t::write_newline()
+{
+    if (indent < 0)
+        return;
+
+    out.put('\n');
+}
+
+void value::dump(dump_context_t& context, int level) const
+{
+    context.write_indent(level);
+
+    switch (m_Type)
+    {
+        case type_t::null:
+            context.out << "null";
+            break;
+
+        case type_t::object:
+            context.out << '{';
+            {
+                context.write_newline();
+                bool first = true;
+                for (auto& entry : *object_ptr(m_Storage))
+                {
+                    if (!first) { context.out << ','; context.write_newline(); } else first = false;
+                    context.write_indent(level + 1);
+                    context.out << '\"' << entry.first << "\":";
+                    if (!entry.second.is_structured())
+                    {
+                        context.write_separator();
+                        entry.second.dump(context, 0);
+                    }
+                    else
+                    {
+                        context.write_newline();
+                        entry.second.dump(context, level + 1);
+                    }
+                }
+                if (!first)
+                    context.write_newline();
+            }
+            context.write_indent(level);
+            context.out << '}';
+            break;
+
+        case type_t::array:
+            context.out << '[';
+            {
+                context.write_newline();
+                bool first = true;
+                for (auto& entry : *array_ptr(m_Storage))
+                {
+                    if (!first) { context.out << ','; context.write_newline(); } else first = false;
+                    if (!entry.is_structured())
+                    {
+                        context.write_indent(level + 1);
+                        entry.dump(context, 0);
+                    }
+                    else
+                    {
+                        entry.dump(context, level + 1);
+                    }
+                }
+                if (!first)
+                    context.write_newline();
+            }
+            context.write_indent(level);
+            context.out << ']';
+            break;
+
+        case type_t::string:
+            context.out << '\"';
+
+            if (string_ptr(m_Storage)->find_first_of("\"\\/\b\f\n\r") != string::npos || string_ptr(m_Storage)->find('\0') != string::npos)
+            {
+                for (auto c : *string_ptr(m_Storage))
+                {
+                         if (c == '\"')  context.out << "\\\"";
+                    else if (c == '\\')  context.out << "\\\\";
+                    else if (c == '/')   context.out << "\\/";
+                    else if (c == '\b')  context.out << "\\b";
+                    else if (c == '\f')  context.out << "\\f";
+                    else if (c == '\n')  context.out << "\\n";
+                    else if (c == '\r')  context.out << "\\r";
+                    else if (c == '\t')  context.out << "\\t";
+                    else if (c == 0)     context.out << "\\u0000";
+                    else                 context.out << c;
+                }
+            }
+            else
+                context.out << *string_ptr(m_Storage);
+            context.out << '\"';
+            break;
+
+
+        case type_t::boolean:
+            if (*boolean_ptr(m_Storage))
+                context.out << "true";
+            else
+                context.out << "false";
+            break;
+
+        case type_t::number:
+            context.out << *number_ptr(m_Storage);
+            break;
+
+        default:
+            break;
+    }
+}
+
+struct value::parser
+{
+    parser(const char* begin, const char* end)
+        : m_Cursor(begin)
+        , m_End(end)
+    {
+    }
+
+    value parse()
+    {
+        value v;
+
+        // Switch to C locale to make strtod and strtol work as expected
+        auto previous_locale = std::setlocale(LC_NUMERIC, "C");
+
+        // Accept single value only when end of the stream is reached.
+        if (!accept_element(v) || !eof())
+            v = value(type_t::discarded);
+
+        if (previous_locale && strcmp(previous_locale, "C") != 0)
+            std::setlocale(LC_NUMERIC, previous_locale);
+
+        return v;
+    }
+
+private:
+    struct cursor_state
+    {
+        cursor_state(parser* p)
+            : m_Owner(p)
+            , m_LastCursor(p->m_Cursor)
+        {
+        }
+
+        void reset()
+        {
+            m_Owner->m_Cursor = m_LastCursor;
+        }
+
+        bool operator()(bool accept)
+        {
+            if (!accept)
+                reset();
+            else
+                m_LastCursor = m_Owner->m_Cursor;
+            return accept;
+        }
+
+    private:
+        parser*     m_Owner;
+        const char* m_LastCursor;
+    };
+
+    cursor_state state()
+    {
+        return cursor_state(this);
+    }
+
+    bool accept_value(value& result)
+    {
+        return accept_object(result)
+            || accept_array(result)
+            || accept_string(result)
+            || accept_number(result)
+            || accept_boolean(result)
+            || accept_null(result);
+    }
+
+    bool accept_object(value& result)
+    {
+        auto s = state();
+
+        object o;
+        if (s(accept('{') && accept_ws() && accept('}')))
+        {
+            result = o;
+            return true;
+        }
+        else if (s(accept('{') && accept_members(o) && accept('}')))
+        {
+            result = std::move(o);
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_members(object& o)
+    {
+        if (!accept_member(o))
+            return false;
+
+        while (true)
+        {
+            auto s = state();
+            if (!s(accept(',') && accept_member(o)))
+                break;
+        }
+
+        return true;
+    }
+
+    bool accept_member(object& o)
+    {
+        auto s = state();
+
+        value key;
+        value v;
+        if (s(accept_ws() && accept_string(key) && accept_ws() && accept(':') && accept_element(v)))
+        {
+            o.emplace(std::move(key.get<string>()), std::move(v));
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_array(value& result)
+    {
+        auto s = state();
+
+        if (s(accept('[') && accept_ws() && accept(']')))
+        {
+            result = array();
+            return true;
+        }
+
+        array a;
+        if (s(accept('[') && accept_elements(a) && accept(']')))
+        {
+            result = std::move(a);
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_elements(array& a)
+    {
+        value v;
+        if (!accept_element(v))
+            return false;
+
+        a.emplace_back(std::move(v));
+        while (true)
+        {
+            auto s = state();
+            v = nullptr;
+            if (!s(accept(',') && accept_element(v)))
+                break;
+            a.emplace_back(std::move(v));
+        }
+
+        return true;
+    }
+
+    bool accept_element(value& result)
+    {
+        auto s = state();
+        return s(accept_ws() && accept_value(result) && accept_ws());
+    }
+
+    bool accept_string(value& result)
+    {
+        auto s = state();
+
+        string v;
+        if (s(accept('\"') && accept_characters(v) && accept('\"')))
+        {
+            result = std::move(v);
+            return true;
+        }
+        else
+            return false;
+    }
+
+    bool accept_characters(string& result)
+    {
+        int c;
+        while (accept_character(c))
+        {
+            CRUDE_ASSERT(c < 128); // #todo: convert characters > 127 to UTF-8
+            result.push_back(static_cast<char>(c));
+        }
+
+        return true;
+    }
+
+    bool accept_character(int& c)
+    {
+        auto s = state();
+
+        if (accept('\\'))
+        {
+            return accept_escape(c);
+        }
+        else if (expect('\"'))
+            return false;
+
+        // #todo: Handle UTF-8 sequences.
+        return s((c = peek()) >= 0) && advance();
+    }
+
+    bool accept_escape(int& c)
+    {
+        if (accept('\"')) { c = '\"'; return true; }
+        if (accept('\\')) { c = '\\'; return true; }
+        if (accept('/'))  { c = '/';  return true; }
+        if (accept('b'))  { c = '\b'; return true; }
+        if (accept('f'))  { c = '\f'; return true; }
+        if (accept('n'))  { c = '\n'; return true; }
+        if (accept('r'))  { c = '\r'; return true; }
+        if (accept('t'))  { c = '\t'; return true; }
+
+        auto s = state();
+
+        string hex;
+        hex.reserve(4);
+        if (s(accept('u') && accept_hex(hex) && accept_hex(hex) && accept_hex(hex) && accept_hex(hex)))
+        {
+            char* end = nullptr;
+            auto v = std::strtol(hex.c_str(), &end, 16);
+            if (end != hex.c_str() + hex.size())
+                return false;
+
+            c = v;
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_hex(string& result)
+    {
+        if (accept_digit(result))
+            return true;
+
+        auto c = peek();
+        if ((c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f'))
+        {
+            advance();
+            result.push_back(static_cast<char>(c));
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_number(value& result)
+    {
+        auto s = state();
+
+        string n;
+        if (s(accept_int(n) && accept_frac(n) && accept_exp(n)))
+        {
+            char* end = nullptr;
+            auto v = std::strtod(n.c_str(), &end);
+            if (end != n.c_str() + n.size())
+                return false;
+
+            if (v != 0 && !std::isnormal(v))
+                return false;
+
+            result = v;
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_int(string& result)
+    {
+        auto s = state();
+
+        string part;
+        if (s(accept_onenine(part) && accept_digits(part)))
+        {
+            result += std::move(part);
+            return true;
+        }
+
+        part.resize(0);
+        if (accept_digit(part))
+        {
+            result += std::move(part);
+            return true;
+        }
+
+        part.resize(0);
+        if (s(accept('-') && accept_onenine(part) && accept_digits(part)))
+        {
+            result += '-';
+            result += std::move(part);
+            return true;
+        }
+
+        part.resize(0);
+        if (s(accept('-') && accept_digit(part)))
+        {
+            result += '-';
+            result += std::move(part);
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_digits(string& result)
+    {
+        string part;
+        if (!accept_digit(part))
+            return false;
+
+        while (accept_digit(part))
+            ;
+
+        result += std::move(part);
+
+        return true;
+    }
+
+    bool accept_digit(string& result)
+    {
+        if (accept('0'))
+        {
+            result.push_back('0');
+            return true;
+        }
+        else if (accept_onenine(result))
+            return true;
+
+        return false;
+    }
+
+    bool accept_onenine(string& result)
+    {
+        auto c = peek();
+        if (c >= '1' && c <= '9')
+        {
+            result.push_back(static_cast<char>(c));
+            return advance();
+        }
+
+        return false;
+    }
+
+    bool accept_frac(string& result)
+    {
+        auto s = state();
+
+        string part;
+        if (s(accept('.') && accept_digits(part)))
+        {
+            result += '.';
+            result += std::move(part);
+        }
+
+        return true;
+    }
+
+    bool accept_exp(string& result)
+    {
+        auto s = state();
+
+        string part;
+        if (s(accept('e') && accept_sign(part) && accept_digits(part)))
+        {
+            result += 'e';
+            result += std::move(part);
+            return true;
+        }
+        part.resize(0);
+        if (s(accept('E') && accept_sign(part) && accept_digits(part)))
+        {
+            result += 'E';
+            result += std::move(part);
+        }
+
+        return true;
+    }
+
+    bool accept_sign(string& result)
+    {
+        if (accept('+'))
+            result.push_back('+');
+        else if (accept('-'))
+            result.push_back('-');
+
+        return true;
+    }
+
+    bool accept_ws()
+    {
+        while (expect('\x09') || expect('\x0A') || expect('\x0D') || expect('\x20'))
+            advance();
+        return true;
+    }
+
+    bool accept_boolean(value& result)
+    {
+        if (accept("true"))
+        {
+            result = true;
+            return true;
+        }
+        else if (accept("false"))
+        {
+            result = false;
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept_null(value& result)
+    {
+        if (accept("null"))
+        {
+            result = nullptr;
+            return true;
+        }
+
+        return false;
+    }
+
+    bool accept(char c)
+    {
+        if (expect(c))
+            return advance();
+        else
+            return false;
+    }
+
+    bool accept(const char* str)
+    {
+        auto last = m_Cursor;
+
+        while (*str)
+        {
+            if (eof() || *str != *m_Cursor)
+            {
+                m_Cursor = last;
+                return false;
+            }
+
+            advance();
+            ++str;
+        }
+
+        return true;
+    }
+
+    int peek() const
+    {
+        if (!eof())
+            return *m_Cursor;
+        else
+            return -1;
+    }
+
+    bool expect(char c)
+    {
+        return peek() == c;
+    }
+
+    bool advance(int count = 1)
+    {
+        if (m_Cursor + count > m_End)
+        {
+            m_Cursor = m_End;
+            return false;
+        }
+
+        m_Cursor += count;
+
+        return true;
+    }
+
+    bool eof() const
+    {
+        return m_Cursor == m_End;
+    }
+
+    const char* m_Cursor;
+    const char* m_End;
+};
+
+value value::parse(const string& data)
+{
+    auto p = parser(data.c_str(), data.c_str() + data.size());
+
+    auto v = p.parse();
+
+    return v;
+}
+
+} // namespace crude_json
diff --git a/3rdparty/imgui-node-editor/crude_json.h b/3rdparty/imgui-node-editor/crude_json.h
new file mode 100644
index 0000000..06eedd7
--- /dev/null
+++ b/3rdparty/imgui-node-editor/crude_json.h
@@ -0,0 +1,223 @@
+// Crude implementation of JSON value object and parser.
+//
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+# ifndef __CRUDE_JSON_H__
+# define __CRUDE_JSON_H__
+# pragma once
+
+# include <type_traits>
+# include <string>
+# include <vector>
+# include <map>
+# include <cstddef>
+# include <algorithm>
+# include <sstream>
+
+# ifndef CRUDE_ASSERT
+#     include <cassert>
+#     define CRUDE_ASSERT(expr) assert(expr)
+# endif
+
+namespace crude_json {
+
+struct value;
+
+using string  = std::string;
+using object  = std::map<string, value>;
+using array   = std::vector<value>;
+using number  = double;
+using boolean = bool;
+using null    = std::nullptr_t;
+
+enum class type_t
+{
+    null,
+    object,
+    array,
+    string,
+    boolean,
+    number,
+    discarded
+};
+
+struct value
+{
+    value(type_t type = type_t::null): m_Type(construct(m_Storage, type)) {}
+    value(value&& other);
+    value(const value& other);
+
+    value(      null)      : m_Type(construct(m_Storage,      null()))  {}
+    value(      object&& v): m_Type(construct(m_Storage, std::move(v))) {}
+    value(const object&  v): m_Type(construct(m_Storage,           v))  {}
+    value(      array&&  v): m_Type(construct(m_Storage, std::move(v))) {}
+    value(const array&   v): m_Type(construct(m_Storage,           v))  {}
+    value(      string&& v): m_Type(construct(m_Storage, std::move(v))) {}
+    value(const string&  v): m_Type(construct(m_Storage,           v))  {}
+    value(const char*    v): m_Type(construct(m_Storage,           v))  {}
+    value(      boolean  v): m_Type(construct(m_Storage,           v))  {}
+    value(      number   v): m_Type(construct(m_Storage,           v))  {}
+    ~value() { destruct(m_Storage, m_Type); }
+
+    value& operator=(value&& other)      { if (this != &other) { value(std::move(other)).swap(*this); } return *this; }
+    value& operator=(const value& other) { if (this != &other) { value(          other).swap(*this);  } return *this; }
+
+    value& operator=(      null)       { auto other = value(           );  swap(other); return *this; }
+    value& operator=(      object&& v) { auto other = value(std::move(v)); swap(other); return *this; }
+    value& operator=(const object&  v) { auto other = value(          v);  swap(other); return *this; }
+    value& operator=(      array&&  v) { auto other = value(std::move(v)); swap(other); return *this; }
+    value& operator=(const array&   v) { auto other = value(          v);  swap(other); return *this; }
+    value& operator=(      string&& v) { auto other = value(std::move(v)); swap(other); return *this; }
+    value& operator=(const string&  v) { auto other = value(          v);  swap(other); return *this; }
+    value& operator=(const char*    v) { auto other = value(          v);  swap(other); return *this; }
+    value& operator=(      boolean  v) { auto other = value(          v);  swap(other); return *this; }
+    value& operator=(      number   v) { auto other = value(          v);  swap(other); return *this; }
+
+    type_t type() const { return m_Type; }
+
+    operator type_t() const { return m_Type; }
+
+          value& operator[](size_t index);
+    const value& operator[](size_t index) const;
+          value& operator[](const string& key);
+    const value& operator[](const string& key) const;
+
+    bool contains(const string& key) const;
+
+    void push_back(const value& value);
+    void push_back(value&& value);
+
+    bool is_primitive()  const { return is_string() || is_number() || is_boolean() || is_null(); }
+    bool is_structured() const { return is_object() || is_array();   }
+    bool is_null()       const { return m_Type == type_t::null;      }
+    bool is_object()     const { return m_Type == type_t::object;    }
+    bool is_array()      const { return m_Type == type_t::array;     }
+    bool is_string()     const { return m_Type == type_t::string;    }
+    bool is_boolean()    const { return m_Type == type_t::boolean;   }
+    bool is_number()     const { return m_Type == type_t::number;    }
+    bool is_discarded()  const { return m_Type == type_t::discarded; }
+
+    template <typename T> const T& get() const;
+    template <typename T>       T& get();
+
+    string dump(const int indent = -1, const char indent_char = ' ') const;
+
+    void swap(value& other);
+
+    inline friend void swap(value& lhs, value& rhs) { lhs.swap(rhs); }
+
+    // Returns discarded value for invalid inputs.
+    static value parse(const string& data);
+
+private:
+    struct parser;
+
+    // VS2015: std::max() is not constexpr yet.
+# define CRUDE_MAX2(a, b)           ((a) < (b) ? (b) : (a))
+# define CRUDE_MAX3(a, b, c)        CRUDE_MAX2(CRUDE_MAX2(a, b), c)
+# define CRUDE_MAX4(a, b, c, d)     CRUDE_MAX2(CRUDE_MAX3(a, b, c), d)
+# define CRUDE_MAX5(a, b, c, d, e)  CRUDE_MAX2(CRUDE_MAX4(a, b, c, d), e)
+    enum
+    {
+        max_size  = CRUDE_MAX5( sizeof(string),  sizeof(object),  sizeof(array),  sizeof(number),  sizeof(boolean)),
+        max_align = CRUDE_MAX5(alignof(string), alignof(object), alignof(array), alignof(number), alignof(boolean))
+    };
+# undef CRUDE_MAX5
+# undef CRUDE_MAX4
+# undef CRUDE_MAX3
+# undef CRUDE_MAX2
+    using storage_t = std::aligned_storage<max_size, max_align>::type;
+
+    static       object*   object_ptr(      storage_t& storage) { return reinterpret_cast<       object*>(&storage); }
+    static const object*   object_ptr(const storage_t& storage) { return reinterpret_cast<const  object*>(&storage); }
+    static       array*     array_ptr(      storage_t& storage) { return reinterpret_cast<        array*>(&storage); }
+    static const array*     array_ptr(const storage_t& storage) { return reinterpret_cast<const   array*>(&storage); }
+    static       string*   string_ptr(      storage_t& storage) { return reinterpret_cast<       string*>(&storage); }
+    static const string*   string_ptr(const storage_t& storage) { return reinterpret_cast<const  string*>(&storage); }
+    static       boolean* boolean_ptr(      storage_t& storage) { return reinterpret_cast<      boolean*>(&storage); }
+    static const boolean* boolean_ptr(const storage_t& storage) { return reinterpret_cast<const boolean*>(&storage); }
+    static       number*   number_ptr(      storage_t& storage) { return reinterpret_cast<       number*>(&storage); }
+    static const number*   number_ptr(const storage_t& storage) { return reinterpret_cast<const  number*>(&storage); }
+
+    static type_t construct(storage_t& storage, type_t type)
+    {
+        switch (type)
+        {
+            case type_t::object:    new (&storage) object();  break;
+            case type_t::array:     new (&storage) array();   break;
+            case type_t::string:    new (&storage) string();  break;
+            case type_t::boolean:   new (&storage) boolean(); break;
+            case type_t::number:    new (&storage) number();  break;
+            default: break;
+        }
+
+        return type;
+    }
+
+    static type_t construct(storage_t& storage,       null)           { (void)storage;                                        return type_t::null;    }
+    static type_t construct(storage_t& storage,       object&& value) { new (&storage)  object(std::forward<object>(value));  return type_t::object;  }
+    static type_t construct(storage_t& storage, const object&  value) { new (&storage)  object(value);                        return type_t::object;  }
+    static type_t construct(storage_t& storage,       array&&  value) { new (&storage)   array(std::forward<array>(value));   return type_t::array;   }
+    static type_t construct(storage_t& storage, const array&   value) { new (&storage)   array(value);                        return type_t::array;   }
+    static type_t construct(storage_t& storage,       string&& value) { new (&storage)  string(std::forward<string>(value));  return type_t::string;  }
+    static type_t construct(storage_t& storage, const string&  value) { new (&storage)  string(value);                        return type_t::string;  }
+    static type_t construct(storage_t& storage, const char*    value) { new (&storage)  string(value);                        return type_t::string;  }
+    static type_t construct(storage_t& storage,       boolean  value) { new (&storage) boolean(value);                        return type_t::boolean; }
+    static type_t construct(storage_t& storage,       number   value) { new (&storage)  number(value);                        return type_t::number;  }
+
+    static void destruct(storage_t& storage, type_t type)
+    {
+        switch (type)
+        {
+            case type_t::object: object_ptr(storage)->~object(); break;
+            case type_t::array:   array_ptr(storage)->~array();  break;
+            case type_t::string: string_ptr(storage)->~string(); break;
+            default: break;
+        }
+    }
+
+    struct dump_context_t
+    {
+        std::ostringstream out;
+        const int  indent = -1;
+        const char indent_char = ' ';
+
+        // VS2015: Aggregate initialization isn't a thing yet.
+        dump_context_t(const int indent, const char indent_char)
+            : indent(indent)
+            , indent_char(indent_char)
+        {
+        }
+
+        void write_indent(int level);
+        void write_separator();
+        void write_newline();
+    };
+
+    void dump(dump_context_t& context, int level) const;
+
+    storage_t m_Storage;
+    type_t    m_Type;
+};
+
+template <> inline const object&  value::get<object>()  const { CRUDE_ASSERT(m_Type == type_t::object);  return *object_ptr(m_Storage);  }
+template <> inline const array&   value::get<array>()   const { CRUDE_ASSERT(m_Type == type_t::array);   return *array_ptr(m_Storage);   }
+template <> inline const string&  value::get<string>()  const { CRUDE_ASSERT(m_Type == type_t::string);  return *string_ptr(m_Storage);  }
+template <> inline const boolean& value::get<boolean>() const { CRUDE_ASSERT(m_Type == type_t::boolean); return *boolean_ptr(m_Storage); }
+template <> inline const number&  value::get<number>()  const { CRUDE_ASSERT(m_Type == type_t::number);  return *number_ptr(m_Storage);  }
+
+template <> inline       object&  value::get<object>()        { CRUDE_ASSERT(m_Type == type_t::object);  return *object_ptr(m_Storage);  }
+template <> inline       array&   value::get<array>()         { CRUDE_ASSERT(m_Type == type_t::array);   return *array_ptr(m_Storage);   }
+template <> inline       string&  value::get<string>()        { CRUDE_ASSERT(m_Type == type_t::string);  return *string_ptr(m_Storage);  }
+template <> inline       boolean& value::get<boolean>()       { CRUDE_ASSERT(m_Type == type_t::boolean); return *boolean_ptr(m_Storage); }
+template <> inline       number&  value::get<number>()        { CRUDE_ASSERT(m_Type == type_t::number);  return *number_ptr(m_Storage);  }
+
+
+} // namespace crude_json
+
+# endif // __CRUDE_JSON_H__
\ No newline at end of file
diff --git a/3rdparty/imgui-node-editor/imgui_bezier_math.h b/3rdparty/imgui-node-editor/imgui_bezier_math.h
new file mode 100644
index 0000000..09b76e7
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_bezier_math.h
@@ -0,0 +1,142 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# ifndef __IMGUI_BEZIER_MATH_H__
+# define __IMGUI_BEZIER_MATH_H__
+# pragma once
+
+
+//------------------------------------------------------------------------------
+# include "imgui_extra_math.h"
+
+
+//------------------------------------------------------------------------------
+template <typename T>
+struct ImCubicBezierPointsT
+{
+    T P0;
+    T P1;
+    T P2;
+    T P3;
+};
+using ImCubicBezierPoints = ImCubicBezierPointsT<ImVec2>;
+
+
+//------------------------------------------------------------------------------
+// Low-level Bezier curve sampling.
+template <typename T> inline T ImLinearBezier(const T& p0, const T& p1, float t);
+template <typename T> inline T ImLinearBezierDt(const T& p0, const T& p1, float t);
+template <typename T> inline T ImQuadraticBezier(const T& p0, const T& p1, const T& p2, float t);
+template <typename T> inline T ImQuadraticBezierDt(const T& p0, const T& p1, const T& p2, float t);
+template <typename T> inline T ImCubicBezier(const T& p0, const T& p1, const T& p2, const T& p3, float t);
+template <typename T> inline T ImCubicBezierDt(const T& p0, const T& p1, const T& p2, const T& p3, float t);
+
+
+// High-level Bezier sampling, automatically collapse to lower level Bezier curves if control points overlap.
+template <typename T> inline T ImCubicBezierSample(const T& p0, const T& p1, const T& p2, const T& p3, float t);
+template <typename T> inline T ImCubicBezierSample(const ImCubicBezierPointsT<T>& curve, float t);
+template <typename T> inline T ImCubicBezierTangent(const T& p0, const T& p1, const T& p2, const T& p3, float t);
+template <typename T> inline T ImCubicBezierTangent(const ImCubicBezierPointsT<T>& curve, float t);
+
+
+// Calculate approximate length of Cubic Bezier curve.
+template <typename T> inline float ImCubicBezierLength(const T& p0, const T& p1, const T& p2, const T& p3);
+template <typename T> inline float ImCubicBezierLength(const ImCubicBezierPointsT<T>& curve);
+
+
+// Splits Cubic Bezier curve into two curves.
+template <typename T>
+struct ImCubicBezierSplitResultT
+{
+    ImCubicBezierPointsT<T> Left;
+    ImCubicBezierPointsT<T> Right;
+};
+using ImCubicBezierSplitResult = ImCubicBezierSplitResultT<ImVec2>;
+
+template <typename T> inline ImCubicBezierSplitResultT<T> ImCubicBezierSplit(const T& p0, const T& p1, const T& p2, const T& p3, float t);
+template <typename T> inline ImCubicBezierSplitResultT<T> ImCubicBezierSplit(const ImCubicBezierPointsT<T>& curve, float t);
+
+
+// Returns bounding rectangle of Cubic Bezier curve.
+inline ImRect ImCubicBezierBoundingRect(const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3);
+inline ImRect ImCubicBezierBoundingRect(const ImCubicBezierPoints& curve);
+
+
+// Project point on Cubic Bezier curve.
+struct ImProjectResult
+{
+    ImVec2 Point;    // Point on curve
+    float  Time;     // [0 - 1]
+    float  Distance; // Distance to curve
+};
+
+inline ImProjectResult ImProjectOnCubicBezier(const ImVec2& p, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const int subdivisions = 100);
+inline ImProjectResult ImProjectOnCubicBezier(const ImVec2& p, const ImCubicBezierPoints& curve, const int subdivisions = 100);
+
+
+// Calculate intersection between line and a Cubic Bezier curve.
+struct ImCubicBezierIntersectResult
+{
+    int Count;
+    ImVec2 Points[3];
+};
+
+inline ImCubicBezierIntersectResult ImCubicBezierLineIntersect(const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& a0, const ImVec2& a1);
+inline ImCubicBezierIntersectResult ImCubicBezierLineIntersect(const ImCubicBezierPoints& curve, const ImLine& line);
+
+
+// Adaptive Cubic Bezier subdivision.
+enum ImCubicBezierSubdivideFlags
+{
+    ImCubicBezierSubdivide_None        = 0,
+    ImCubicBezierSubdivide_SkipFirst   = 1
+};
+
+struct ImCubicBezierSubdivideSample
+{
+    ImVec2 Point;
+    ImVec2 Tangent;
+};
+
+using ImCubicBezierSubdivideCallback = void (*)(const ImCubicBezierSubdivideSample& p, void* user_pointer);
+
+inline void ImCubicBezierSubdivide(ImCubicBezierSubdivideCallback callback, void* user_pointer, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
+inline void ImCubicBezierSubdivide(ImCubicBezierSubdivideCallback callback, void* user_pointer, const ImCubicBezierPoints& curve, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
+
+
+// F has signature void(const ImCubicBezierSubdivideSample& p)
+template <typename F> inline void ImCubicBezierSubdivide(F& callback, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
+template <typename F> inline void ImCubicBezierSubdivide(F& callback, const ImCubicBezierPoints& curve, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
+
+// Fixed step Cubic Bezier subdivision.
+struct ImCubicBezierFixedStepSample
+{
+    float  T;
+    float  Length;
+    ImVec2 Point;
+    bool   BreakSearch;
+};
+
+using ImCubicBezierFixedStepCallback = void (*)(ImCubicBezierFixedStepSample& sample, void* user_pointer);
+
+inline void ImCubicBezierFixedStep(ImCubicBezierFixedStepCallback callback, void* user_pointer, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
+inline void ImCubicBezierFixedStep(ImCubicBezierFixedStepCallback callback, void* user_pointer, const ImCubicBezierPoints& curve, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
+
+
+// F has signature void(const ImCubicBezierFixedStepSample& p)
+template <typename F> inline void ImCubicBezierFixedStep(F& callback, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
+template <typename F> inline void ImCubicBezierFixedStep(F& callback, const ImCubicBezierPoints& curve, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
+
+
+//------------------------------------------------------------------------------
+# include "imgui_bezier_math.inl"
+
+
+//------------------------------------------------------------------------------
+# endif // __IMGUI_BEZIER_MATH_H__
diff --git a/3rdparty/imgui-node-editor/imgui_bezier_math.inl b/3rdparty/imgui-node-editor/imgui_bezier_math.inl
new file mode 100644
index 0000000..c2c7c43
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_bezier_math.inl
@@ -0,0 +1,670 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# ifndef __IMGUI_BEZIER_MATH_INL__
+# define __IMGUI_BEZIER_MATH_INL__
+# pragma once
+
+
+//------------------------------------------------------------------------------
+# include "imgui_bezier_math.h"
+# include <map> // used in ImCubicBezierFixedStep
+
+
+//------------------------------------------------------------------------------
+template <typename T>
+inline T ImLinearBezier(const T& p0, const T& p1, float t)
+{
+    return p0 + t * (p1 - p0);
+}
+
+template <typename T>
+inline T ImLinearBezierDt(const T& p0, const T& p1, float t)
+{
+    IM_UNUSED(t);
+
+    return p1 - p0;
+}
+
+template <typename T>
+inline T ImQuadraticBezier(const T& p0, const T& p1, const T& p2, float t)
+{
+    const auto a = 1 - t;
+
+    return a * a * p0 + 2 * t * a * p1 + t * t * p2;
+}
+
+template <typename T>
+inline T ImQuadraticBezierDt(const T& p0, const T& p1, const T& p2, float t)
+{
+    return 2 * (1 - t) * (p1 - p0) + 2 * t * (p2 - p1);
+}
+
+template <typename T>
+inline T ImCubicBezier(const T& p0, const T& p1, const T& p2, const T& p3, float t)
+{
+    const auto a = 1 - t;
+    const auto b = a * a * a;
+    const auto c = t * t * t;
+
+    return b * p0 + 3 * t * a * a * p1 + 3 * t * t * a * p2 + c * p3;
+}
+
+template <typename T>
+inline T ImCubicBezierDt(const T& p0, const T& p1, const T& p2, const T& p3, float t)
+{
+    const auto a = 1 - t;
+    const auto b = a * a;
+    const auto c = t * t;
+    const auto d = 2 * t * a;
+
+    return -3 * p0 * b + 3 * p1 * (b - d) + 3 * p2 * (d - c) + 3 * p3 * c;
+}
+
+template <typename T>
+inline T ImCubicBezierSample(const T& p0, const T& p1, const T& p2, const T& p3, float t)
+{
+    const auto cp0_zero = ImLengthSqr(p1 - p0) < 1e-5f;
+    const auto cp1_zero = ImLengthSqr(p3 - p2) < 1e-5f;
+
+    if (cp0_zero && cp1_zero)
+        return ImLinearBezier(p0, p3, t);
+    else if (cp0_zero)
+        return ImQuadraticBezier(p0, p2, p3, t);
+    else if (cp1_zero)
+        return ImQuadraticBezier(p0, p1, p3, t);
+    else
+        return ImCubicBezier(p0, p1, p2, p3, t);
+}
+
+template <typename T>
+inline T ImCubicBezierSample(const ImCubicBezierPointsT<T>& curve, float t)
+{
+    return ImCubicBezierSample(curve.P0, curve.P1, curve.P2, curve.P3, t);
+}
+
+template <typename T>
+inline T ImCubicBezierTangent(const T& p0, const T& p1, const T& p2, const T& p3, float t)
+{
+    const auto cp0_zero = ImLengthSqr(p1 - p0) < 1e-5f;
+    const auto cp1_zero = ImLengthSqr(p3 - p2) < 1e-5f;
+
+    if (cp0_zero && cp1_zero)
+        return ImLinearBezierDt(p0, p3, t);
+    else if (cp0_zero)
+        return ImQuadraticBezierDt(p0, p2, p3, t);
+    else if (cp1_zero)
+        return ImQuadraticBezierDt(p0, p1, p3, t);
+    else
+        return ImCubicBezierDt(p0, p1, p2, p3, t);
+}
+
+template <typename T>
+inline T ImCubicBezierTangent(const ImCubicBezierPointsT<T>& curve, float t)
+{
+    return ImCubicBezierTangent(curve.P0, curve.P1, curve.P2, curve.P3, t);
+}
+
+template <typename T>
+inline float ImCubicBezierLength(const T& p0, const T& p1, const T& p2, const T& p3)
+{
+    // Legendre-Gauss abscissae with n=24 (x_i values, defined at i=n as the roots of the nth order Legendre polynomial Pn(x))
+    static const float t_values[] =
+    {
+        -0.0640568928626056260850430826247450385909f,
+         0.0640568928626056260850430826247450385909f,
+        -0.1911188674736163091586398207570696318404f,
+         0.1911188674736163091586398207570696318404f,
+        -0.3150426796961633743867932913198102407864f,
+         0.3150426796961633743867932913198102407864f,
+        -0.4337935076260451384870842319133497124524f,
+         0.4337935076260451384870842319133497124524f,
+        -0.5454214713888395356583756172183723700107f,
+         0.5454214713888395356583756172183723700107f,
+        -0.6480936519369755692524957869107476266696f,
+         0.6480936519369755692524957869107476266696f,
+        -0.7401241915785543642438281030999784255232f,
+         0.7401241915785543642438281030999784255232f,
+        -0.8200019859739029219539498726697452080761f,
+         0.8200019859739029219539498726697452080761f,
+        -0.8864155270044010342131543419821967550873f,
+         0.8864155270044010342131543419821967550873f,
+        -0.9382745520027327585236490017087214496548f,
+         0.9382745520027327585236490017087214496548f,
+        -0.9747285559713094981983919930081690617411f,
+         0.9747285559713094981983919930081690617411f,
+        -0.9951872199970213601799974097007368118745f,
+         0.9951872199970213601799974097007368118745f
+    };
+
+    // Legendre-Gauss weights with n=24 (w_i values, defined by a function linked to in the Bezier primer article)
+    static const float c_values[] =
+    {
+        0.1279381953467521569740561652246953718517f,
+        0.1279381953467521569740561652246953718517f,
+        0.1258374563468282961213753825111836887264f,
+        0.1258374563468282961213753825111836887264f,
+        0.1216704729278033912044631534762624256070f,
+        0.1216704729278033912044631534762624256070f,
+        0.1155056680537256013533444839067835598622f,
+        0.1155056680537256013533444839067835598622f,
+        0.1074442701159656347825773424466062227946f,
+        0.1074442701159656347825773424466062227946f,
+        0.0976186521041138882698806644642471544279f,
+        0.0976186521041138882698806644642471544279f,
+        0.0861901615319532759171852029837426671850f,
+        0.0861901615319532759171852029837426671850f,
+        0.0733464814110803057340336152531165181193f,
+        0.0733464814110803057340336152531165181193f,
+        0.0592985849154367807463677585001085845412f,
+        0.0592985849154367807463677585001085845412f,
+        0.0442774388174198061686027482113382288593f,
+        0.0442774388174198061686027482113382288593f,
+        0.0285313886289336631813078159518782864491f,
+        0.0285313886289336631813078159518782864491f,
+        0.0123412297999871995468056670700372915759f,
+        0.0123412297999871995468056670700372915759f
+    };
+
+    static_assert(sizeof(t_values) / sizeof(*t_values) == sizeof(c_values) / sizeof(*c_values), "");
+
+    auto arc = [p0, p1, p2, p3](float t)
+    {
+        const auto p = ImCubicBezierDt(p0, p1, p2, p3, t);
+        const auto l = ImLength(p);
+        return l;
+    };
+
+    const auto z = 0.5f;
+    const auto n = sizeof(t_values) / sizeof(*t_values);
+
+    auto accumulator = 0.0f;
+    for (size_t i = 0; i < n; ++i)
+    {
+        const auto t = z * t_values[i] + z;
+        accumulator += c_values[i] * arc(t);
+    }
+
+    return z * accumulator;
+}
+
+template <typename T>
+inline float ImCubicBezierLength(const ImCubicBezierPointsT<T>& curve)
+{
+    return ImCubicBezierLength(curve.P0, curve.P1, curve.P2, curve.P3);
+}
+
+template <typename T>
+inline ImCubicBezierSplitResultT<T> ImCubicBezierSplit(const T& p0, const T& p1, const T& p2, const T& p3, float t)
+{
+    const auto z1 = t;
+    const auto z2 = z1 * z1;
+    const auto z3 = z1 * z1 * z1;
+    const auto s1 = z1 - 1;
+    const auto s2 = s1 * s1;
+    const auto s3 = s1 * s1 * s1;
+
+    return ImCubicBezierSplitResultT<T>
+    {
+        ImCubicBezierPointsT<T>
+        {
+                                                                 p0,
+                                             z1      * p1 - s1 * p0,
+                          z2      * p2 - 2 * z1 * s1 * p1 + s2 * p0,
+            z3 * p3 - 3 * z2 * s1 * p2 + 3 * z1 * s2 * p1 - s3 * p0
+        },
+        ImCubicBezierPointsT<T>
+        {
+            z3 * p0 - 3 * z2 * s1 * p1 + 3 * z1 * s2 * p2 - s3 * p3,
+                          z2      * p1 - 2 * z1 * s1 * p2 + s2 * p3,
+                                             z1      * p2 - s1 * p3,
+                                                                 p3,
+        }
+    };
+}
+
+template <typename T>
+inline ImCubicBezierSplitResultT<T> ImCubicBezierSplit(const ImCubicBezierPointsT<T>& curve, float t)
+{
+    return ImCubicBezierSplit(curve.P0, curve.P1, curve.P2, curve.P3, t);
+}
+
+inline ImRect ImCubicBezierBoundingRect(const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3)
+{
+    auto a = 3 * p3 - 9 * p2 + 9 * p1 - 3 * p0;
+    auto b = 6 * p0 - 12 * p1 + 6 * p2;
+    auto c = 3 * p1 - 3 * p0;
+    auto delta_squared = ImMul(b, b) - 4 * ImMul(a, c);
+
+    auto tl = ImMin(p0, p3);
+    auto rb = ImMax(p0, p3);
+
+# define IM_VEC2_INDEX(v, i) *(&v.x + i)
+
+    for (int i = 0; i < 2; ++i)
+    {
+        if (IM_VEC2_INDEX(delta_squared, i) >= 0)
+        {
+            auto delta = ImSqrt(IM_VEC2_INDEX(delta_squared, i));
+
+            auto t0 = (-IM_VEC2_INDEX(b, i) + delta) / (2 * IM_VEC2_INDEX(a, i));
+            if (t0 > 0 && t0 < 1)
+            {
+                auto p = ImCubicBezier(IM_VEC2_INDEX(p0, i), IM_VEC2_INDEX(p1, i), IM_VEC2_INDEX(p2, i), IM_VEC2_INDEX(p3, i), t0);
+                IM_VEC2_INDEX(tl, i) = ImMin(IM_VEC2_INDEX(tl, i), p);
+                IM_VEC2_INDEX(rb, i) = ImMax(IM_VEC2_INDEX(rb, i), p);
+            }
+
+            auto t1 = (-IM_VEC2_INDEX(b, i) - delta) / (2 * IM_VEC2_INDEX(a, i));
+            if (t1 > 0 && t1 < 1)
+            {
+                auto p = ImCubicBezier(IM_VEC2_INDEX(p0, i), IM_VEC2_INDEX(p1, i), IM_VEC2_INDEX(p2, i), IM_VEC2_INDEX(p3, i), t1);
+                IM_VEC2_INDEX(tl, i) = ImMin(IM_VEC2_INDEX(tl, i), p);
+                IM_VEC2_INDEX(rb, i) = ImMax(IM_VEC2_INDEX(rb, i), p);
+            }
+        }
+    }
+
+# undef IM_VEC2_INDEX
+
+    return ImRect(tl, rb);
+}
+
+inline ImRect ImCubicBezierBoundingRect(const ImCubicBezierPoints& curve)
+{
+    return ImCubicBezierBoundingRect(curve.P0, curve.P1, curve.P2, curve.P3);
+}
+
+inline ImProjectResult ImProjectOnCubicBezier(const ImVec2& point, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const int subdivisions)
+{
+    // http://pomax.github.io/bezierinfo/#projections
+
+    const float epsilon    = 1e-5f;
+    const float fixed_step = 1.0f / static_cast<float>(subdivisions - 1);
+
+    ImProjectResult result;
+    result.Point    = point;
+    result.Time     = 0.0f;
+    result.Distance = FLT_MAX;
+
+    // Step 1: Coarse check
+    for (int i = 0; i < subdivisions; ++i)
+    {
+        auto t = i * fixed_step;
+        auto p = ImCubicBezier(p0, p1, p2, p3, t);
+        auto s = point - p;
+        auto d = ImDot(s, s);
+
+        if (d < result.Distance)
+        {
+            result.Point    = p;
+            result.Time     = t;
+            result.Distance = d;
+        }
+    }
+
+    if (result.Time == 0.0f || ImFabs(result.Time - 1.0f) <= epsilon)
+    {
+        result.Distance = ImSqrt(result.Distance);
+        return result;
+    }
+
+    // Step 2: Fine check
+    auto left  = result.Time - fixed_step;
+    auto right = result.Time + fixed_step;
+    auto step  = fixed_step * 0.1f;
+
+    for (auto t = left; t < right + step; t += step)
+    {
+        auto p = ImCubicBezier(p0, p1, p2, p3, t);
+        auto s = point - p;
+        auto d = ImDot(s, s);
+
+        if (d < result.Distance)
+        {
+            result.Point    = p;
+            result.Time     = t;
+            result.Distance = d;
+        }
+    }
+
+    result.Distance = ImSqrt(result.Distance);
+
+    return result;
+}
+
+inline ImProjectResult ImProjectOnCubicBezier(const ImVec2& p, const ImCubicBezierPoints& curve, const int subdivisions)
+{
+    return ImProjectOnCubicBezier(p, curve.P0, curve.P1, curve.P2, curve.P3, subdivisions);
+}
+
+inline ImCubicBezierIntersectResult ImCubicBezierLineIntersect(const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& a0, const ImVec2& a1)
+{
+    auto cubic_roots = [](float a, float b, float c, float d, float* roots) -> int
+    {
+        int count = 0;
+
+        auto sign = [](float x) -> float { return x < 0 ? -1.0f : 1.0f; };
+
+        auto A = b / a;
+        auto B = c / a;
+        auto C = d / a;
+
+        auto Q = (3 * B - ImPow(A, 2)) / 9;
+        auto R = (9 * A * B - 27 * C - 2 * ImPow(A, 3)) / 54;
+        auto D = ImPow(Q, 3) + ImPow(R, 2);               // polynomial discriminant
+
+        if (D >= 0) // complex or duplicate roots
+        {
+            auto S = sign(R + ImSqrt(D)) * ImPow(ImFabs(R + ImSqrt(D)), (1.0f / 3.0f));
+            auto T = sign(R - ImSqrt(D)) * ImPow(ImFabs(R - ImSqrt(D)), (1.0f / 3.0f));
+
+            roots[0] = -A / 3 + (S + T);                // real root
+            roots[1] = -A / 3 - (S + T) / 2;            // real part of complex root
+            roots[2] = -A / 3 - (S + T) / 2;            // real part of complex root
+            auto Im = ImFabs(ImSqrt(3) * (S - T) / 2);  // complex part of root pair
+
+                                                        // discard complex roots
+            if (Im != 0)
+                count = 1;
+            else
+                count = 3;
+        }
+        else                                            // distinct real roots
+        {
+            auto th = ImAcos(R / ImSqrt(-ImPow(Q, 3)));
+
+            roots[0] = 2 * ImSqrt(-Q) * ImCos(th / 3) - A / 3;
+            roots[1] = 2 * ImSqrt(-Q) * ImCos((th + 2 * IM_PI) / 3) - A / 3;
+            roots[2] = 2 * ImSqrt(-Q) * ImCos((th + 4 * IM_PI) / 3) - A / 3;
+
+            count = 3;
+        }
+
+        return count;
+    };
+
+    // https://github.com/kaishiqi/Geometric-Bezier/blob/master/GeometricBezier/src/kaishiqi/geometric/intersection/Intersection.as
+    //
+    // Start with Bezier using Bernstein polynomials for weighting functions:
+    //     (1-t^3)P0 + 3t(1-t)^2P1 + 3t^2(1-t)P2 + t^3P3
+    //
+    // Expand and collect terms to form linear combinations of original Bezier
+    // controls.  This ends up with a vector cubic in t:
+    //     (-P0+3P1-3P2+P3)t^3 + (3P0-6P1+3P2)t^2 + (-3P0+3P1)t + P0
+    //             /\                  /\                /\       /\
+    //             ||                  ||                ||       ||
+    //             c3                  c2                c1       c0
+
+    // Calculate the coefficients
+    auto c3 =     -p0 + 3 * p1 - 3 * p2 + p3;
+    auto c2 =  3 * p0 - 6 * p1 + 3 * p2;
+    auto c1 = -3 * p0 + 3 * p1;
+    auto c0 =      p0;
+
+    // Convert line to normal form: ax + by + c = 0
+    auto a = a1.y - a0.y;
+    auto b = a0.x - a1.x;
+    auto c = a0.x * (a0.y - a1.y) + a0.y * (a1.x - a0.x);
+
+    // Rotate each cubic coefficient using line for new coordinate system?
+    // Find roots of rotated cubic
+    float roots[3];
+    auto rootCount = cubic_roots(
+        a * c3.x + b * c3.y,
+        a * c2.x + b * c2.y,
+        a * c1.x + b * c1.y,
+        a * c0.x + b * c0.y + c,
+        roots);
+
+    // Any roots in closed interval [0,1] are intersections on Bezier, but
+    // might not be on the line segment.
+    // Find intersections and calculate point coordinates
+
+    auto min = ImMin(a0, a1);
+    auto max = ImMax(a0, a1);
+
+    ImCubicBezierIntersectResult result;
+    auto points = result.Points;
+
+    for (int i = 0; i < rootCount; ++i)
+    {
+        auto root = roots[i];
+
+        if (0 <= root && root <= 1)
+        {
+            // We're within the Bezier curve
+            // Find point on Bezier
+            auto p = ImCubicBezier(p0, p1, p2, p3, root);
+
+            // See if point is on line segment
+            // Had to make special cases for vertical and horizontal lines due
+            // to slight errors in calculation of p00
+            if (a0.x == a1.x)
+            {
+                if (min.y <= p.y && p.y <= max.y)
+                    *points++ = p;
+            }
+            else if (a0.y == a1.y)
+            {
+                if (min.x <= p.x && p.x <= max.x)
+                    *points++ = p;
+            }
+            else if (p.x >= min.x && p.y >= min.y && p.x <= max.x && p.y <= max.y)
+            {
+                *points++ = p;
+            }
+        }
+    }
+
+    result.Count = static_cast<int>(points - result.Points);
+
+    return result;
+}
+
+inline ImCubicBezierIntersectResult ImCubicBezierLineIntersect(const ImCubicBezierPoints& curve, const ImLine& line)
+{
+    return ImCubicBezierLineIntersect(curve.P0, curve.P1, curve.P2, curve.P3, line.A, line.B);
+}
+
+inline void ImCubicBezierSubdivide(ImCubicBezierSubdivideCallback callback, void* user_pointer, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float tess_tol, ImCubicBezierSubdivideFlags flags)
+{
+    return ImCubicBezierSubdivide(callback, user_pointer, ImCubicBezierPoints{ p0, p1, p2, p3 }, tess_tol, flags);
+}
+
+inline void ImCubicBezierSubdivide(ImCubicBezierSubdivideCallback callback, void* user_pointer, const ImCubicBezierPoints& curve, float tess_tol, ImCubicBezierSubdivideFlags flags)
+{
+    struct Tesselator
+    {
+        ImCubicBezierSubdivideCallback  Callback;
+        void*                           UserPointer;
+        float                           TesselationTollerance;
+        ImCubicBezierSubdivideFlags     Flags;
+
+        void Commit(const ImVec2& p, const ImVec2& t)
+        {
+            ImCubicBezierSubdivideSample sample;
+            sample.Point = p;
+            sample.Tangent = t;
+            Callback(sample, UserPointer);
+        }
+
+        void Subdivide(const ImCubicBezierPoints& curve, int level = 0)
+        {
+            float dx = curve.P3.x - curve.P0.x;
+            float dy = curve.P3.y - curve.P0.y;
+            float d2 = ((curve.P1.x - curve.P3.x) * dy - (curve.P1.y - curve.P3.y) * dx);
+            float d3 = ((curve.P2.x - curve.P3.x) * dy - (curve.P2.y - curve.P3.y) * dx);
+            d2 = (d2 >= 0) ? d2 : -d2;
+            d3 = (d3 >= 0) ? d3 : -d3;
+            if ((d2 + d3) * (d2 + d3) < TesselationTollerance * (dx * dx + dy * dy))
+            {
+                Commit(curve.P3, ImCubicBezierTangent(curve, 1.0f));
+            }
+            else if (level < 10)
+            {
+                const auto p12 = (curve.P0 + curve.P1) * 0.5f;
+                const auto p23 = (curve.P1 + curve.P2) * 0.5f;
+                const auto p34 = (curve.P2 + curve.P3) * 0.5f;
+                const auto p123 = (p12 + p23) * 0.5f;
+                const auto p234 = (p23 + p34) * 0.5f;
+                const auto p1234 = (p123 + p234) * 0.5f;
+
+                Subdivide(ImCubicBezierPoints { curve.P0, p12, p123, p1234 }, level + 1);
+                Subdivide(ImCubicBezierPoints { p1234, p234, p34, curve.P3 }, level + 1);
+            }
+        }
+    };
+
+    if (tess_tol < 0)
+        tess_tol = 1.118f; // sqrtf(1.25f)
+
+    Tesselator tesselator;
+    tesselator.Callback              = callback;
+    tesselator.UserPointer           = user_pointer;
+    tesselator.TesselationTollerance = tess_tol * tess_tol;
+    tesselator.Flags                 = flags;
+
+    if (!(tesselator.Flags & ImCubicBezierSubdivide_SkipFirst))
+        tesselator.Commit(curve.P0, ImCubicBezierTangent(curve, 0.0f));
+
+    tesselator.Subdivide(curve, 0);
+}
+
+template <typename F> inline void ImCubicBezierSubdivide(F& callback, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float tess_tol, ImCubicBezierSubdivideFlags flags)
+{
+    auto handler = [](const ImCubicBezierSubdivideSample& p, void* user_pointer)
+    {
+        auto& callback = *reinterpret_cast<F*>(user_pointer);
+        callback(p);
+    };
+
+    ImCubicBezierSubdivide(handler, &callback, ImCubicBezierPoints{ p0, p1, p2, p3 }, tess_tol, flags);
+}
+
+template <typename F> inline void ImCubicBezierSubdivide(F& callback, const ImCubicBezierPoints& curve, float tess_tol, ImCubicBezierSubdivideFlags flags)
+{
+    auto handler = [](const ImCubicBezierSubdivideSample& p, void* user_pointer)
+    {
+        auto& callback = *reinterpret_cast<F*>(user_pointer);
+        callback(p);
+    };
+
+    ImCubicBezierSubdivide(handler, &callback, curve, tess_tol, flags);
+}
+
+inline void ImCubicBezierFixedStep(ImCubicBezierFixedStepCallback callback, void* user_pointer, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float step, bool overshoot, float max_value_error, float max_t_error)
+{
+    if (step <= 0.0f || !callback || max_value_error <= 0 || max_t_error <= 0)
+        return;
+
+    ImCubicBezierFixedStepSample sample;
+    sample.T           = 0.0f;
+    sample.Length      = 0.0f;
+    sample.Point       = p0;
+    sample.BreakSearch = false;
+
+    callback(sample, user_pointer);
+    if (sample.BreakSearch)
+        return;
+
+    const auto total_length = ImCubicBezierLength(p0, p1, p2, p3);
+    const auto point_count  = static_cast<int>(total_length / step) + (overshoot ? 2 : 1);
+    const auto t_min        = 0.0f;
+    const auto t_max        = step * point_count / total_length;
+    const auto t_0          = (t_min + t_max) * 0.5f;
+
+    // #todo: replace map with ImVector + binary search
+    std::map<float, float> cache;
+    for (int point_index = 1; point_index < point_count; ++point_index)
+    {
+        const auto targetLength = point_index * step;
+
+        float t_start = t_min;
+        float t_end   = t_max;
+        float t       = t_0;
+
+        float t_best     = t;
+        float error_best = total_length;
+
+        while (true)
+        {
+            auto cacheIt = cache.find(t);
+            if (cacheIt == cache.end())
+            {
+                const auto front        = ImCubicBezierSplit(p0, p1, p2, p3, t).Left;
+                const auto split_length = ImCubicBezierLength(front);
+
+                cacheIt = cache.emplace(t, split_length).first;
+            }
+
+            const auto length   = cacheIt->second;
+            const auto error    = targetLength - length;
+
+            if (error < error_best)
+            {
+                error_best = error;
+                t_best     = t;
+            }
+
+            if (ImFabs(error) <= max_value_error || ImFabs(t_start - t_end) <= max_t_error)
+            {
+                sample.T      = t;
+                sample.Length = length;
+                sample.Point  = ImCubicBezier(p0, p1, p2, p3, t);
+
+                callback(sample, user_pointer);
+                if (sample.BreakSearch)
+                    return;
+
+                break;
+            }
+            else if (error < 0.0f)
+                t_end = t;
+            else // if (error > 0.0f)
+                t_start = t;
+
+            t = (t_start + t_end) * 0.5f;
+        }
+    }
+}
+
+inline void ImCubicBezierFixedStep(ImCubicBezierFixedStepCallback callback, void* user_pointer, const ImCubicBezierPoints& curve, float step, bool overshoot, float max_value_error, float max_t_error)
+{
+    ImCubicBezierFixedStep(callback, user_pointer, curve.P0, curve.P1, curve.P2, curve.P3, step, overshoot, max_value_error, max_t_error);
+}
+
+// F has signature void(const ImCubicBezierFixedStepSample& p)
+template <typename F>
+inline void ImCubicBezierFixedStep(F& callback, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float step, bool overshoot, float max_value_error, float max_t_error)
+{
+    auto handler = [](ImCubicBezierFixedStepSample& sample, void* user_pointer)
+    {
+        auto& callback = *reinterpret_cast<F*>(user_pointer);
+        callback(sample);
+    };
+
+    ImCubicBezierFixedStep(handler, &callback, p0, p1, p2, p3, step, overshoot, max_value_error, max_t_error);
+}
+
+template <typename F>
+inline void ImCubicBezierFixedStep(F& callback, const ImCubicBezierPoints& curve, float step, bool overshoot, float max_value_error, float max_t_error)
+{
+    auto handler = [](ImCubicBezierFixedStepSample& sample, void* user_pointer)
+    {
+        auto& callback = *reinterpret_cast<F*>(user_pointer);
+        callback(sample);
+    };
+
+    ImCubicBezierFixedStep(handler, &callback, curve.P0, curve.P1, curve.P2, curve.P3, step, overshoot, max_value_error, max_t_error);
+}
+
+
+//------------------------------------------------------------------------------
+# endif // __IMGUI_BEZIER_MATH_INL__
diff --git a/3rdparty/imgui-node-editor/imgui_canvas.cpp b/3rdparty/imgui-node-editor/imgui_canvas.cpp
new file mode 100644
index 0000000..df63a40
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_canvas.cpp
@@ -0,0 +1,513 @@
+# define IMGUI_DEFINE_MATH_OPERATORS
+# include "imgui_canvas.h"
+# include <type_traits>
+
+// https://stackoverflow.com/a/36079786
+# define DECLARE_HAS_MEMBER(__trait_name__, __member_name__)                         \
+                                                                                     \
+    template <typename __boost_has_member_T__>                                       \
+    class __trait_name__                                                             \
+    {                                                                                \
+        using check_type = ::std::remove_const_t<__boost_has_member_T__>;            \
+        struct no_type {char x[2];};                                                 \
+        using  yes_type = char;                                                      \
+                                                                                     \
+        struct  base { void __member_name__() {}};                                   \
+        struct mixin : public base, public check_type {};                            \
+                                                                                     \
+        template <void (base::*)()> struct aux {};                                   \
+                                                                                     \
+        template <typename U> static no_type  test(aux<&U::__member_name__>*);       \
+        template <typename U> static yes_type test(...);                             \
+                                                                                     \
+        public:                                                                      \
+                                                                                     \
+        static constexpr bool value = (sizeof(yes_type) == sizeof(test<mixin>(0)));  \
+    }
+
+namespace ImCanvasDetails {
+
+DECLARE_HAS_MEMBER(HasFringeScale, _FringeScale);
+
+struct FringeScaleRef
+{
+    // Overload is present when ImDrawList does have _FringeScale member variable.
+    template <typename T>
+    static float& Get(typename std::enable_if<HasFringeScale<T>::value, T>::type* drawList)
+    {
+        return drawList->_FringeScale;
+    }
+
+    // Overload is present when ImDrawList does not have _FringeScale member variable.
+    template <typename T>
+    static float& Get(typename std::enable_if<!HasFringeScale<T>::value, T>::type*)
+    {
+        static float placeholder = 1.0f;
+        return placeholder;
+    }
+};
+
+DECLARE_HAS_MEMBER(HasVtxCurrentOffset, _VtxCurrentOffset);
+
+struct VtxCurrentOffsetRef
+{
+    // Overload is present when ImDrawList does have _FringeScale member variable.
+    template <typename T>
+    static unsigned int& Get(typename std::enable_if<HasVtxCurrentOffset<T>::value, T>::type* drawList)
+    {
+        return drawList->_VtxCurrentOffset;
+    }
+
+    // Overload is present when ImDrawList does not have _FringeScale member variable.
+    template <typename T>
+    static unsigned int& Get(typename std::enable_if<!HasVtxCurrentOffset<T>::value, T>::type* drawList)
+    {
+        return drawList->_CmdHeader.VtxOffset;
+    }
+};
+
+} // namespace ImCanvasDetails
+
+// Returns a reference to _FringeScale extension to ImDrawList
+//
+// If ImDrawList does not have _FringeScale a placeholder is returned.
+static inline float& ImFringeScaleRef(ImDrawList* drawList)
+{
+    using namespace ImCanvasDetails;
+    return FringeScaleRef::Get<ImDrawList>(drawList);
+}
+
+static inline unsigned int& ImVtxOffsetRef(ImDrawList* drawList)
+{
+    using namespace ImCanvasDetails;
+    return VtxCurrentOffsetRef::Get<ImDrawList>(drawList);
+}
+
+static inline ImVec2 ImSelectPositive(const ImVec2& lhs, const ImVec2& rhs) { return ImVec2(lhs.x > 0.0f ? lhs.x : rhs.x, lhs.y > 0.0f ? lhs.y : rhs.y); }
+
+bool ImGuiEx::Canvas::Begin(const char* id, const ImVec2& size)
+{
+    return Begin(ImGui::GetID(id), size);
+}
+
+bool ImGuiEx::Canvas::Begin(ImGuiID id, const ImVec2& size)
+{
+    IM_ASSERT(m_InBeginEnd == false);
+
+    m_WidgetPosition = ImGui::GetCursorScreenPos();
+    m_WidgetSize = ImSelectPositive(size, ImGui::GetContentRegionAvail());
+    m_WidgetRect = ImRect(m_WidgetPosition, m_WidgetPosition + m_WidgetSize);
+    m_DrawList = ImGui::GetWindowDrawList();
+
+    UpdateViewTransformPosition();
+
+    if (ImGui::IsClippedEx(m_WidgetRect, id, false))
+        return false;
+
+    // Save current channel, so we can assert when user
+    // call canvas API with different one.
+    m_ExpectedChannel = m_DrawList->_Splitter._Current;
+
+    // #debug: Canvas content.
+    //m_DrawList->AddRectFilled(m_StartPos, m_StartPos + m_CurrentSize, IM_COL32(0, 0, 0, 64));
+    m_DrawList->AddRect(m_WidgetRect.Min, m_WidgetRect.Max, IM_COL32(255, 0, 255, 64));
+
+    ImGui::SetCursorScreenPos(ImVec2(0.0f, 0.0f));
+
+# if IMGUI_EX_CANVAS_DEFERED()
+    m_Ranges.resize(0);
+# endif
+
+    SaveInputState();
+    SaveViewportState();
+
+    EnterLocalSpace();
+
+    // Emit dummy widget matching bounds of the canvas.
+    ImGui::SetCursorScreenPos(m_ViewRect.Min);
+    ImGui::Dummy(m_ViewRect.GetSize());
+
+    ImGui::SetCursorScreenPos(ImVec2(0.0f, 0.0f));
+
+    m_InBeginEnd = true;
+
+    return true;
+}
+
+void ImGuiEx::Canvas::End()
+{
+    // If you're here your call to Begin() returned false,
+    // or Begin() wasn't called at all.
+    IM_ASSERT(m_InBeginEnd == true);
+
+    // If you're here, please make sure you do not interleave
+    // channel splitter with canvas.
+    // Always call canvas function with using same channel.
+    IM_ASSERT(m_DrawList->_Splitter._Current == m_ExpectedChannel);
+
+    //auto& io = ImGui::GetIO();
+
+    // Check: Unmatched calls to Suspend() / Resume(). Please check your code.
+    IM_ASSERT(m_SuspendCounter == 0);
+
+    LeaveLocalSpace();
+
+    // Emit dummy widget matching bounds of the canvas.
+    ImGui::SetCursorScreenPos(m_WidgetPosition);
+    ImGui::Dummy(m_WidgetSize);
+
+    // #debug: Rect around canvas. Content should be inside these bounds.
+    //m_DrawList->AddRect(m_WidgetPosition - ImVec2(1.0f, 1.0f), m_WidgetPosition + m_WidgetSize + ImVec2(1.0f, 1.0f), IM_COL32(196, 0, 0, 255));
+
+    m_InBeginEnd = false;
+}
+
+void ImGuiEx::Canvas::SetView(const ImVec2& origin, float scale)
+{
+    SetView(CanvasView(origin, scale));
+}
+
+void ImGuiEx::Canvas::SetView(const CanvasView& view)
+{
+    if (m_InBeginEnd)
+        LeaveLocalSpace();
+
+    if (m_View.Origin.x != view.Origin.x || m_View.Origin.y != view.Origin.y)
+    {
+        m_View.Origin = view.Origin;
+
+        UpdateViewTransformPosition();
+    }
+
+    if (m_View.Scale != view.Scale)
+    {
+        m_View.Scale    = view.Scale;
+        m_View.InvScale = view.InvScale;
+    }
+
+    if (m_InBeginEnd)
+        EnterLocalSpace();
+}
+
+void ImGuiEx::Canvas::CenterView(const ImVec2& canvasPoint)
+{
+    auto view = CalcCenterView(canvasPoint);
+    SetView(view);
+}
+
+ImGuiEx::CanvasView ImGuiEx::Canvas::CalcCenterView(const ImVec2& canvasPoint) const
+{
+    auto localCenter = ToLocal(m_WidgetPosition + m_WidgetSize * 0.5f);
+    auto localOffset = canvasPoint - localCenter;
+    auto offset      = FromLocalV(localOffset);
+
+    return CanvasView{ m_View.Origin - offset, m_View.Scale };
+}
+
+void ImGuiEx::Canvas::CenterView(const ImRect& canvasRect)
+{
+    auto view = CalcCenterView(canvasRect);
+
+    SetView(view);
+}
+
+ImGuiEx::CanvasView ImGuiEx::Canvas::CalcCenterView(const ImRect& canvasRect) const
+{
+    auto canvasRectSize = canvasRect.GetSize();
+
+    if (canvasRectSize.x <= 0.0f || canvasRectSize.y <= 0.0f)
+        return View();
+
+    auto widgetAspectRatio     = m_WidgetSize.y   > 0.0f ? m_WidgetSize.x   / m_WidgetSize.y   : 0.0f;
+    auto canvasRectAspectRatio = canvasRectSize.y > 0.0f ? canvasRectSize.x / canvasRectSize.y : 0.0f;
+
+    if (widgetAspectRatio <= 0.0f || canvasRectAspectRatio <= 0.0f)
+        return View();
+
+    auto newOrigin = m_View.Origin;
+    auto newScale  = m_View.Scale;
+    if (canvasRectAspectRatio > widgetAspectRatio)
+    {
+        // width span across view
+        newScale = m_WidgetSize.x / canvasRectSize.x;
+        newOrigin = canvasRect.Min * -newScale;
+        newOrigin.y += (m_WidgetSize.y - canvasRectSize.y * newScale) * 0.5f;
+    }
+    else
+    {
+        // height span across view
+        newScale = m_WidgetSize.y / canvasRectSize.y;
+        newOrigin = canvasRect.Min * -newScale;
+        newOrigin.x += (m_WidgetSize.x - canvasRectSize.x * newScale) * 0.5f;
+    }
+
+    return CanvasView{ newOrigin, newScale };
+}
+
+void ImGuiEx::Canvas::Suspend()
+{
+    // If you're here, please make sure you do not interleave
+    // channel splitter with canvas.
+    // Always call canvas function with using same channel.
+    IM_ASSERT(m_DrawList->_Splitter._Current == m_ExpectedChannel);
+
+    if (m_SuspendCounter == 0)
+        LeaveLocalSpace();
+
+    ++m_SuspendCounter;
+}
+
+void ImGuiEx::Canvas::Resume()
+{
+    // If you're here, please make sure you do not interleave
+    // channel splitter with canvas.
+    // Always call canvas function with using same channel.
+    IM_ASSERT(m_DrawList->_Splitter._Current == m_ExpectedChannel);
+
+    // Check: Number of calls to Resume() do not match calls to Suspend(). Please check your code.
+    IM_ASSERT(m_SuspendCounter > 0);
+    if (--m_SuspendCounter == 0)
+        EnterLocalSpace();
+}
+
+ImVec2 ImGuiEx::Canvas::FromLocal(const ImVec2& point) const
+{
+    return point * m_View.Scale + m_ViewTransformPosition;
+}
+
+ImVec2 ImGuiEx::Canvas::FromLocal(const ImVec2& point, const CanvasView& view) const
+{
+    return point * view.Scale + view.Origin + m_WidgetPosition;
+}
+
+ImVec2 ImGuiEx::Canvas::FromLocalV(const ImVec2& vector) const
+{
+    return vector * m_View.Scale;
+}
+
+ImVec2 ImGuiEx::Canvas::FromLocalV(const ImVec2& vector, const CanvasView& view) const
+{
+    return vector * view.Scale;
+}
+
+ImVec2 ImGuiEx::Canvas::ToLocal(const ImVec2& point) const
+{
+    return (point - m_ViewTransformPosition) * m_View.InvScale;
+}
+
+ImVec2 ImGuiEx::Canvas::ToLocal(const ImVec2& point, const CanvasView& view) const
+{
+    return (point - view.Origin - m_WidgetPosition) * view.InvScale;
+}
+
+ImVec2 ImGuiEx::Canvas::ToLocalV(const ImVec2& vector) const
+{
+    return vector * m_View.InvScale;
+}
+
+ImVec2 ImGuiEx::Canvas::ToLocalV(const ImVec2& vector, const CanvasView& view) const
+{
+    return vector * view.InvScale;
+}
+
+ImRect ImGuiEx::Canvas::CalcViewRect(const CanvasView& view) const
+{
+    ImRect result;
+    result.Min = ImVec2(-view.Origin.x, -view.Origin.y) * view.InvScale;
+    result.Max = (m_WidgetSize - view.Origin) * view.InvScale;
+    return result;
+}
+
+void ImGuiEx::Canvas::UpdateViewTransformPosition()
+{
+    m_ViewTransformPosition = m_View.Origin + m_WidgetPosition;
+}
+
+void ImGuiEx::Canvas::SaveInputState()
+{
+    auto& io = ImGui::GetIO();
+    m_MousePosBackup = io.MousePos;
+    m_MousePosPrevBackup = io.MousePosPrev;
+    for (auto i = 0; i < IM_ARRAYSIZE(m_MouseClickedPosBackup); ++i)
+        m_MouseClickedPosBackup[i] = io.MouseClickedPos[i];
+
+    // Record cursor max to prevent scrollbars from appearing.
+    m_WindowCursorMaxBackup = ImGui::GetCurrentWindow()->DC.CursorMaxPos;
+}
+
+void ImGuiEx::Canvas::RestoreInputState()
+{
+    auto& io = ImGui::GetIO();
+    io.MousePos = m_MousePosBackup;
+    io.MousePosPrev = m_MousePosPrevBackup;
+    for (auto i = 0; i < IM_ARRAYSIZE(m_MouseClickedPosBackup); ++i)
+        io.MouseClickedPos[i] = m_MouseClickedPosBackup[i];
+    ImGui::GetCurrentWindow()->DC.CursorMaxPos = m_WindowCursorMaxBackup;
+}
+
+void ImGuiEx::Canvas::SaveViewportState()
+{
+# if defined(IMGUI_HAS_VIEWPORT)
+    auto viewport = ImGui::GetWindowViewport();
+
+    m_ViewportPosBackup = viewport->Pos;
+    m_ViewportSizeBackup = viewport->Size;
+# endif
+}
+
+void ImGuiEx::Canvas::RestoreViewportState()
+{
+# if defined(IMGUI_HAS_VIEWPORT)
+    auto viewport = ImGui::GetWindowViewport();
+
+    viewport->Pos = m_ViewportPosBackup;
+    viewport->Size = m_ViewportSizeBackup;
+# endif
+}
+
+void ImGuiEx::Canvas::EnterLocalSpace()
+{
+    // Prepare ImDrawList for drawing in local coordinate system:
+    //   - determine visible part of the canvas
+    //   - start unique draw command
+    //   - add clip rect matching canvas size
+    //   - record current command index
+    //   - record current vertex write index
+
+    // Determine visible part of the canvas. Make it before
+    // adding new command, to avoid round rip where command
+    // is removed in PopClipRect() and added again next PushClipRect().
+    ImGui::PushClipRect(m_WidgetPosition, m_WidgetPosition + m_WidgetSize, true);
+    auto clipped_clip_rect = m_DrawList->_ClipRectStack.back();
+    ImGui::PopClipRect();
+
+    // Make sure we do not share draw command with anyone. We don't want to mess
+    // with someones clip rectangle.
+
+    // #FIXME:
+    //     This condition is not enough to avoid when user choose
+    //     to use channel splitter.
+    //
+    //     To deal with Suspend()/Resume() calls empty draw command
+    //     is always added then splitter is active. Otherwise
+    //     channel merger will collapse our draw command one with
+    //     different clip rectangle.
+    //
+    //     More investigation is needed. To get to the bottom of this.
+    if ((!m_DrawList->CmdBuffer.empty() && m_DrawList->CmdBuffer.back().ElemCount > 0) || m_DrawList->_Splitter._Count > 1)
+        m_DrawList->AddDrawCmd();
+
+# if IMGUI_EX_CANVAS_DEFERED()
+    m_Ranges.resize(m_Ranges.Size + 1);
+    m_CurrentRange = &m_Ranges.back();
+    m_CurrentRange->BeginComandIndex = ImMax(m_DrawList->CmdBuffer.Size - 1, 0);
+    m_CurrentRange->BeginVertexIndex = m_DrawList->_VtxCurrentIdx + ImVtxOffsetRef(m_DrawList);
+# endif
+    m_DrawListCommadBufferSize       = ImMax(m_DrawList->CmdBuffer.Size - 1, 0);
+    m_DrawListStartVertexIndex       = m_DrawList->_VtxCurrentIdx + ImVtxOffsetRef(m_DrawList);
+
+# if defined(IMGUI_HAS_VIEWPORT)
+    auto viewport_min = m_ViewportPosBackup;
+    auto viewport_max = m_ViewportPosBackup + m_ViewportSizeBackup;
+
+    viewport_min.x = (viewport_min.x - m_ViewTransformPosition.x) * m_View.InvScale;
+    viewport_min.y = (viewport_min.y - m_ViewTransformPosition.y) * m_View.InvScale;
+    viewport_max.x = (viewport_max.x - m_ViewTransformPosition.x) * m_View.InvScale;
+    viewport_max.y = (viewport_max.y - m_ViewTransformPosition.y) * m_View.InvScale;
+
+    auto viewport = ImGui::GetWindowViewport();
+    viewport->Pos  = viewport_min;
+    viewport->Size = viewport_max - viewport_min;
+# endif
+
+    // Clip rectangle in parent canvas space and move it to local space.
+    clipped_clip_rect.x = (clipped_clip_rect.x - m_ViewTransformPosition.x) * m_View.InvScale;
+    clipped_clip_rect.y = (clipped_clip_rect.y - m_ViewTransformPosition.y) * m_View.InvScale;
+    clipped_clip_rect.z = (clipped_clip_rect.z - m_ViewTransformPosition.x) * m_View.InvScale;
+    clipped_clip_rect.w = (clipped_clip_rect.w - m_ViewTransformPosition.y) * m_View.InvScale;
+    ImGui::PushClipRect(ImVec2(clipped_clip_rect.x, clipped_clip_rect.y), ImVec2(clipped_clip_rect.z, clipped_clip_rect.w), false);
+
+    // Transform mouse position to local space.
+    auto& io = ImGui::GetIO();
+    io.MousePos     = (m_MousePosBackup - m_ViewTransformPosition) * m_View.InvScale;
+    io.MousePosPrev = (m_MousePosPrevBackup - m_ViewTransformPosition) * m_View.InvScale;
+    for (auto i = 0; i < IM_ARRAYSIZE(m_MouseClickedPosBackup); ++i)
+        io.MouseClickedPos[i] = (m_MouseClickedPosBackup[i] - m_ViewTransformPosition) * m_View.InvScale;
+
+    m_ViewRect = CalcViewRect(m_View);;
+
+    auto& fringeScale = ImFringeScaleRef(m_DrawList);
+    m_LastFringeScale = fringeScale;
+    fringeScale *= m_View.InvScale;
+}
+
+void ImGuiEx::Canvas::LeaveLocalSpace()
+{
+    IM_ASSERT(m_DrawList->_Splitter._Current == m_ExpectedChannel);
+
+# if IMGUI_EX_CANVAS_DEFERED()
+    IM_ASSERT(m_CurrentRange != nullptr);
+
+    m_CurrentRange->EndVertexIndex  = m_DrawList->_VtxCurrentIdx + ImVtxOffsetRef(m_DrawList);
+    m_CurrentRange->EndCommandIndex = m_DrawList->CmdBuffer.size();
+    if (m_CurrentRange->BeginVertexIndex == m_CurrentRange->EndVertexIndex)
+    {
+        // Drop empty range
+        m_Ranges.resize(m_Ranges.Size - 1);
+    }
+    m_CurrentRange = nullptr;
+# endif
+
+    // Move vertices to screen space.
+    auto vertex    = m_DrawList->VtxBuffer.Data + m_DrawListStartVertexIndex;
+    auto vertexEnd = m_DrawList->VtxBuffer.Data + m_DrawList->_VtxCurrentIdx + ImVtxOffsetRef(m_DrawList);
+
+    // If canvas view is not scaled take a faster path.
+    if (m_View.Scale != 1.0f)
+    {
+        while (vertex < vertexEnd)
+        {
+            vertex->pos.x = vertex->pos.x * m_View.Scale + m_ViewTransformPosition.x;
+            vertex->pos.y = vertex->pos.y * m_View.Scale + m_ViewTransformPosition.y;
+            ++vertex;
+        }
+
+        // Move clip rectangles to screen space.
+        for (int i = m_DrawListCommadBufferSize; i < m_DrawList->CmdBuffer.size(); ++i)
+        {
+            auto& command = m_DrawList->CmdBuffer[i];
+            command.ClipRect.x = command.ClipRect.x * m_View.Scale + m_ViewTransformPosition.x;
+            command.ClipRect.y = command.ClipRect.y * m_View.Scale + m_ViewTransformPosition.y;
+            command.ClipRect.z = command.ClipRect.z * m_View.Scale + m_ViewTransformPosition.x;
+            command.ClipRect.w = command.ClipRect.w * m_View.Scale + m_ViewTransformPosition.y;
+        }
+    }
+    else
+    {
+        while (vertex < vertexEnd)
+        {
+            vertex->pos.x = vertex->pos.x + m_ViewTransformPosition.x;
+            vertex->pos.y = vertex->pos.y + m_ViewTransformPosition.y;
+            ++vertex;
+        }
+
+        // Move clip rectangles to screen space.
+        for (int i = m_DrawListCommadBufferSize; i < m_DrawList->CmdBuffer.size(); ++i)
+        {
+            auto& command = m_DrawList->CmdBuffer[i];
+            command.ClipRect.x = command.ClipRect.x + m_ViewTransformPosition.x;
+            command.ClipRect.y = command.ClipRect.y + m_ViewTransformPosition.y;
+            command.ClipRect.z = command.ClipRect.z + m_ViewTransformPosition.x;
+            command.ClipRect.w = command.ClipRect.w + m_ViewTransformPosition.y;
+        }
+    }
+
+    auto& fringeScale = ImFringeScaleRef(m_DrawList);
+    fringeScale = m_LastFringeScale;
+
+    // And pop \o/
+    ImGui::PopClipRect();
+
+    RestoreInputState();
+    RestoreViewportState();
+}
diff --git a/3rdparty/imgui-node-editor/imgui_canvas.h b/3rdparty/imgui-node-editor/imgui_canvas.h
new file mode 100644
index 0000000..44f4347
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_canvas.h
@@ -0,0 +1,258 @@
+// Canvas widget - view over infinite virtual space.
+//
+// Canvas allows you to draw your widgets anywhere over infinite space and provide
+// view over it with support for panning and scaling.
+//
+// When you enter a canvas ImGui is moved to virtual space which mean:
+//   - ImGui::GetCursorScreenPos() return (0, 0) and which correspond to top left corner
+//     of the canvas on the screen (this can be changed usign CanvasView()).
+//   - Mouse input is brought to canvas space, so widgets works as usual.
+//   - Everything you draw with ImDrawList will be in virtual space.
+//
+// By default origin point is on top left corner of canvas widget. It can be
+// changed with call to CanvasView() where you can specify what part of space
+// should be viewed by setting viewport origin point and scale. Current state
+// can be queried with CanvasViewOrigin() and CanvasViewScale().
+//
+// Viewport size is controlled by 'size' parameter in BeginCanvas(). You can query
+// it using CanvasContentMin/Max/Size functions. They are useful if you to not specify
+// canvas size in which case all free space is used.
+//
+// Bounds of visible region of infinite space can be queried using CanvasViewMin/Max/Size
+// functions. Everything that is drawn outside of this region will be clipped
+// as usual in ImGui.
+//
+// While drawing inside canvas you can translate position from world (usual ImGui space)
+// to virtual space and back usign CanvasFromWorld()/CanvasToWorld().
+//
+// Canvas can be nested in each other (they are regular widgets after all). There
+// is a way to transform position between current and parent canvas with
+// CanvasFromParent()/CanvasToParent().
+//
+// Sometimes in more elaborate scenarios you want to move out canvas virtual space,
+// do something and came back. You can do that with SuspendCanvas() and ResumeCanvas().
+//
+// Note:
+//     It is not valid to call canvas API outside of BeginCanvas() / EndCanvas() scope.
+//
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+# ifndef __IMGUI_EX_CANVAS_H__
+# define __IMGUI_EX_CANVAS_H__
+# pragma once
+
+# include <imgui.h>
+# include <imgui_internal.h> // ImRect, ImFloor
+
+namespace ImGuiEx {
+
+struct CanvasView
+{
+    ImVec2 Origin;
+    float  Scale  = 1.0f;
+    float  InvScale = 1.0f;
+
+    CanvasView() = default;
+    CanvasView(const ImVec2& origin, float scale)
+        : Origin(origin)
+        , Scale(scale)
+        , InvScale(scale ? 1.0f / scale : 0.0f)
+    {
+    }
+
+    void Set(const ImVec2& origin, float scale)
+    {
+        *this = CanvasView(origin, scale);
+    }
+};
+
+// Canvas widget represent view over infinite plane.
+//
+// It acts like a child window without scroll bars with
+// ability to zoom to specific part of canvas plane.
+//
+// Widgets are clipped according to current view exactly
+// same way ImGui do. To avoid `missing widgets` artifacts first
+// setup visible region with SetView() then draw content.
+//
+// Everything drawn with ImDrawList betwen calls to Begin()/End()
+// will be drawn on canvas plane. This behavior can be suspended
+// by calling Suspend() and resumed by calling Resume().
+//
+// Warning:
+//     Please do not interleave canvas with use of channel splitter.
+//     Keep channel splitter contained inside canvas or always
+//     call canvas functions from same channel.
+struct Canvas
+{
+    // Begins drawing content of canvas plane.
+    //
+    // When false is returned that mean canvas is not visible to the
+    // user can drawing should be skipped and End() not called.
+    // When true is returned drawing must be ended with call to End().
+    //
+    // If any size component is equal to zero or less canvas will
+    // automatically expand to all available area on that axis.
+    // So (0, 300) will take horizontal space and have height
+    // of 300 points. (0, 0) will take all remaining space of
+    // the window.
+    //
+    // You can query size of the canvas while it is being drawn
+    // by calling Rect().
+    bool Begin(const char* id, const ImVec2& size);
+    bool Begin(ImGuiID id, const ImVec2& size);
+
+    // Ends interaction with canvas plane.
+    //
+    // Must be called only when Begin() retuned true.
+    void End();
+
+    // Sets visible region of canvas plane.
+    //
+    // Origin is an offset of infinite plane origin from top left
+    // corner of the canvas.
+    //
+    // Scale greater than 1 make canvas content be bigger, less than 1 smaller.
+    void SetView(const ImVec2& origin, float scale);
+    void SetView(const CanvasView& view);
+
+    // Centers view over specific point on canvas plane.
+    //
+    // View will be centered on specific point by changing origin
+    // but not scale.
+    void CenterView(const ImVec2& canvasPoint);
+
+    // Calculates view over specific point on canvas plane.
+    CanvasView CalcCenterView(const ImVec2& canvasPoint) const;
+
+    // Centers view over specific rectangle on canvas plane.
+    //
+    // Whole rectangle will fit in canvas view. This will affect both
+    // origin and scale.
+    void CenterView(const ImRect& canvasRect);
+
+    // Calculates view over specific rectangle on canvas plane.
+    CanvasView CalcCenterView(const ImRect& canvasRect) const;
+
+    // Suspends canvas by returning to normal ImGui transformation space.
+    // While suspended UI will not be drawn on canvas plane.
+    //
+    // Calls to Suspend()/Resume() are symetrical. Each call to Suspend()
+    // must be matched with call to Resume().
+    void Suspend();
+    void Resume();
+
+    // Transforms point from canvas plane to ImGui.
+    ImVec2 FromLocal(const ImVec2& point) const;
+    ImVec2 FromLocal(const ImVec2& point, const CanvasView& view) const;
+
+    // Transforms vector from canvas plant to ImGui.
+    ImVec2 FromLocalV(const ImVec2& vector) const;
+    ImVec2 FromLocalV(const ImVec2& vector, const CanvasView& view) const;
+
+    // Transforms point from ImGui to canvas plane.
+    ImVec2 ToLocal(const ImVec2& point) const;
+    ImVec2 ToLocal(const ImVec2& point, const CanvasView& view) const;
+
+    // Transforms vector from ImGui to canvas plane.
+    ImVec2 ToLocalV(const ImVec2& vector) const;
+    ImVec2 ToLocalV(const ImVec2& vector, const CanvasView& view) const;
+
+    // Returns widget bounds.
+    //
+    // Note:
+    //     Rect is valid after call to Begin().
+    const ImRect& Rect() const { return m_WidgetRect; }
+
+    // Returns visible region on canvas plane (in canvas plane coordinates).
+    const ImRect& ViewRect() const { return m_ViewRect; }
+
+    // Calculates visible region for view.
+    ImRect CalcViewRect(const CanvasView& view) const;
+
+    // Returns current view.
+    const CanvasView& View() const { return m_View; }
+
+    // Returns origin of the view.
+    //
+    // Origin is an offset of infinite plane origin from top left
+    // corner of the canvas.
+    const ImVec2& ViewOrigin()  const { return m_View.Origin; }
+
+    // Returns scale of the view.
+    float ViewScale() const { return m_View.Scale; }
+
+    // Returns true if canvas is suspended.
+    //
+    // See: Suspend()/Resume()
+    bool IsSuspended() const { return m_SuspendCounter > 0; }
+
+private:
+# define IMGUI_EX_CANVAS_DEFERED() 0
+
+# if IMGUI_EX_CANVAS_DEFERED()
+    struct Range
+    {
+        int BeginVertexIndex = 0;
+        int EndVertexIndex   = 0;
+        int BeginComandIndex = 0;
+        int EndCommandIndex  = 0;
+    };
+# endif
+
+    void UpdateViewTransformPosition();
+
+    void SaveInputState();
+    void RestoreInputState();
+
+    void SaveViewportState();
+    void RestoreViewportState();
+
+    void EnterLocalSpace();
+    void LeaveLocalSpace();
+
+    bool m_InBeginEnd = false;
+
+    ImVec2 m_WidgetPosition;
+    ImVec2 m_WidgetSize;
+    ImRect m_WidgetRect;
+
+    ImDrawList* m_DrawList = nullptr;
+    int m_ExpectedChannel = 0;
+
+# if IMGUI_EX_CANVAS_DEFERED()
+    ImVector<Range> m_Ranges;
+    Range* m_CurrentRange = nullptr;
+# endif
+
+    int m_DrawListCommadBufferSize = 0;
+    int m_DrawListStartVertexIndex = 0;
+
+    CanvasView  m_View;
+    ImRect      m_ViewRect;
+
+    ImVec2 m_ViewTransformPosition;
+
+    int m_SuspendCounter = 0;
+
+    float m_LastFringeScale = 1.0f;
+
+    ImVec2 m_MousePosBackup;
+    ImVec2 m_MousePosPrevBackup;
+    ImVec2 m_MouseClickedPosBackup[IM_ARRAYSIZE(ImGuiIO::MouseClickedPos)];
+    ImVec2 m_WindowCursorMaxBackup;
+
+# if defined(IMGUI_HAS_VIEWPORT)
+    ImVec2 m_ViewportPosBackup;
+    ImVec2 m_ViewportSizeBackup;
+# endif
+};
+
+} // namespace ImGuiEx
+
+# endif // __IMGUI_EX_CANVAS_H__
\ No newline at end of file
diff --git a/3rdparty/imgui-node-editor/imgui_extra_math.h b/3rdparty/imgui-node-editor/imgui_extra_math.h
new file mode 100644
index 0000000..2a3a2fe
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_extra_math.h
@@ -0,0 +1,71 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# ifndef __IMGUI_EXTRA_MATH_H__
+# define __IMGUI_EXTRA_MATH_H__
+# pragma once
+
+
+//------------------------------------------------------------------------------
+# include <imgui.h>
+# ifndef IMGUI_DEFINE_MATH_OPERATORS
+#     define IMGUI_DEFINE_MATH_OPERATORS
+# endif
+# include <imgui_internal.h>
+
+
+//------------------------------------------------------------------------------
+struct ImLine
+{
+    ImVec2 A, B;
+};
+
+
+//------------------------------------------------------------------------------
+inline bool operator==(const ImVec2& lhs, const ImVec2& rhs);
+inline bool operator!=(const ImVec2& lhs, const ImVec2& rhs);
+inline ImVec2 operator*(const float lhs, const ImVec2& rhs);
+inline ImVec2 operator-(const ImVec2& lhs);
+
+
+//------------------------------------------------------------------------------
+inline float  ImLength(float v);
+inline float  ImLength(const ImVec2& v);
+inline float  ImLengthSqr(float v);
+inline ImVec2 ImNormalized(const ImVec2& v);
+
+
+//------------------------------------------------------------------------------
+inline bool   ImRect_IsEmpty(const ImRect& rect);
+inline ImVec2 ImRect_ClosestPoint(const ImRect& rect, const ImVec2& p, bool snap_to_edge);
+inline ImVec2 ImRect_ClosestPoint(const ImRect& rect, const ImVec2& p, bool snap_to_edge, float radius);
+inline ImVec2 ImRect_ClosestPoint(const ImRect& rect, const ImRect& b);
+inline ImLine ImRect_ClosestLine(const ImRect& rect_a, const ImRect& rect_b);
+inline ImLine ImRect_ClosestLine(const ImRect& rect_a, const ImRect& rect_b, float radius_a, float radius_b);
+
+
+
+//------------------------------------------------------------------------------
+namespace ImEasing {
+
+template <typename V, typename T>
+inline V EaseOutQuad(V b, V c, T t)
+{
+    return b - c * (t * (t - 2));
+}
+
+} // namespace ImEasing
+
+
+//------------------------------------------------------------------------------
+# include "imgui_extra_math.inl"
+
+
+//------------------------------------------------------------------------------
+# endif // __IMGUI_EXTRA_MATH_H__
diff --git a/3rdparty/imgui-node-editor/imgui_extra_math.inl b/3rdparty/imgui-node-editor/imgui_extra_math.inl
new file mode 100644
index 0000000..18fb25e
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_extra_math.inl
@@ -0,0 +1,187 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# ifndef __IMGUI_EXTRA_MATH_INL__
+# define __IMGUI_EXTRA_MATH_INL__
+# pragma once
+
+
+//------------------------------------------------------------------------------
+# include "imgui_extra_math.h"
+
+
+//------------------------------------------------------------------------------
+inline bool operator==(const ImVec2& lhs, const ImVec2& rhs)
+{
+    return lhs.x == rhs.x && lhs.y == rhs.y;
+}
+
+inline bool operator!=(const ImVec2& lhs, const ImVec2& rhs)
+{
+    return lhs.x != rhs.x || lhs.y != rhs.y;
+}
+
+inline ImVec2 operator*(const float lhs, const ImVec2& rhs)
+{
+    return ImVec2(lhs * rhs.x, lhs * rhs.y);
+}
+
+inline ImVec2 operator-(const ImVec2& lhs)
+{
+    return ImVec2(-lhs.x, -lhs.y);
+}
+
+
+//------------------------------------------------------------------------------
+inline float ImLength(float v)
+{
+    return v;
+}
+
+inline float ImLength(const ImVec2& v)
+{
+    return ImSqrt(ImLengthSqr(v));
+}
+
+inline float ImLengthSqr(float v)
+{
+    return v * v;
+}
+
+inline ImVec2 ImNormalized(const ImVec2& v)
+{
+    return v * ImInvLength(v, 0.0f);
+}
+
+
+
+
+//------------------------------------------------------------------------------
+inline bool ImRect_IsEmpty(const ImRect& rect)
+{
+    return rect.Min.x >= rect.Max.x
+        || rect.Min.y >= rect.Max.y;
+}
+
+inline ImVec2 ImRect_ClosestPoint(const ImRect& rect, const ImVec2& p, bool snap_to_edge)
+{
+    if (!snap_to_edge && rect.Contains(p))
+        return p;
+
+    return ImVec2(
+        (p.x > rect.Max.x) ? rect.Max.x : (p.x < rect.Min.x ? rect.Min.x : p.x),
+        (p.y > rect.Max.y) ? rect.Max.y : (p.y < rect.Min.y ? rect.Min.y : p.y)
+    );
+}
+
+inline ImVec2 ImRect_ClosestPoint(const ImRect& rect, const ImVec2& p, bool snap_to_edge, float radius)
+{
+    auto point = ImRect_ClosestPoint(rect, p, snap_to_edge);
+
+    const auto offset      = p - point;
+    const auto distance_sq = offset.x * offset.x + offset.y * offset.y;
+    if (distance_sq <= 0)
+        return point;
+
+    const auto distance = ImSqrt(distance_sq);
+
+    return point + offset * (ImMin(distance, radius) * (1.0f / distance));
+}
+
+inline ImVec2 ImRect_ClosestPoint(const ImRect& rect, const ImRect& other)
+{
+    ImVec2 result;
+    if (other.Min.x >= rect.Max.x)
+        result.x = rect.Max.x;
+    else if (other.Max.x <= rect.Min.x)
+        result.x = rect.Min.x;
+    else
+        result.x = (ImMax(rect.Min.x, other.Min.x) + ImMin(rect.Max.x, other.Max.x)) / 2;
+
+    if (other.Min.y >= rect.Max.y)
+        result.y = rect.Max.y;
+    else if (other.Max.y <= rect.Min.y)
+        result.y = rect.Min.y;
+    else
+        result.y = (ImMax(rect.Min.y, other.Min.y) + ImMin(rect.Max.y, other.Max.y)) / 2;
+
+    return result;
+}
+
+inline ImLine ImRect_ClosestLine(const ImRect& rect_a, const ImRect& rect_b)
+{
+    ImLine result;
+    result.A = ImRect_ClosestPoint(rect_a, rect_b);
+    result.B = ImRect_ClosestPoint(rect_b, rect_a);
+
+    auto distribute = [](float& a, float& b, float a0, float a1, float b0, float b1)
+    {
+        if (a0 >= b1 || a1 <= b0)
+            return;
+
+        const auto aw = a1 - a0;
+        const auto bw = b1 - b0;
+
+        if (aw > bw)
+        {
+            b = b0 + bw - bw * (a - a0) / aw;
+            a = b;
+        }
+        else if (aw < bw)
+        {
+            a = a0 + aw - aw * (b - b0) / bw;
+            b = a;
+        }
+    };
+
+    distribute(result.A.x, result.B.x, rect_a.Min.x, rect_a.Max.x, rect_b.Min.x, rect_b.Max.x);
+    distribute(result.A.y, result.B.y, rect_a.Min.y, rect_a.Max.y, rect_b.Min.y, rect_b.Max.y);
+
+    return result;
+}
+
+inline ImLine ImRect_ClosestLine(const ImRect& rect_a, const ImRect& rect_b, float radius_a, float radius_b)
+{
+    auto line = ImRect_ClosestLine(rect_a, rect_b);
+    if (radius_a < 0)
+        radius_a = 0;
+    if (radius_b < 0)
+        radius_b = 0;
+
+    if (radius_a == 0 && radius_b == 0)
+        return line;
+
+    const auto offset      = line.B - line.A;
+    const auto length_sq   = offset.x * offset.x + offset.y * offset.y;
+    const auto radius_a_sq = radius_a * radius_a;
+    const auto radius_b_sq = radius_b * radius_b;
+
+    if (length_sq <= 0)
+        return line;
+
+    const auto length    = ImSqrt(length_sq);
+    const auto direction = ImVec2(offset.x / length, offset.y / length);
+
+    const auto total_radius_sq = radius_a_sq + radius_b_sq;
+    if (total_radius_sq > length_sq)
+    {
+        const auto scale = length / (radius_a + radius_b);
+        radius_a *= scale;
+        radius_b *= scale;
+    }
+
+    line.A = line.A + (direction * radius_a);
+    line.B = line.B - (direction * radius_b);
+
+    return line;
+}
+
+
+//------------------------------------------------------------------------------
+# endif // __IMGUI_EXTRA_MATH_INL__
diff --git a/3rdparty/imgui-node-editor/imgui_node_editor.cpp b/3rdparty/imgui-node-editor/imgui_node_editor.cpp
new file mode 100644
index 0000000..c1911c3
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_node_editor.cpp
@@ -0,0 +1,5316 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# include "imgui_node_editor_internal.h"
+# include <cstdio> // snprintf
+# include <string>
+# include <fstream>
+# include <bitset>
+# include <climits>
+# include <algorithm>
+# include <sstream>
+# include <streambuf>
+# include <type_traits>
+
+// https://stackoverflow.com/a/8597498
+# define DECLARE_HAS_NESTED(Name, Member)                                          \
+                                                                                   \
+    template<class T>                                                              \
+    struct has_nested_ ## Name                                                     \
+    {                                                                              \
+        typedef char yes;                                                          \
+        typedef yes(&no)[2];                                                       \
+                                                                                   \
+        template<class U> static yes test(decltype(U::Member)*);                   \
+        template<class U> static no  test(...);                                    \
+                                                                                   \
+        static bool const value = sizeof(test<T>(0)) == sizeof(yes);               \
+    };
+
+
+namespace ax {
+namespace NodeEditor {
+namespace Detail {
+
+# define DECLARE_KEY_TESTER(Key)                                                                    \
+    DECLARE_HAS_NESTED(Key, Key)                                                                    \
+    struct KeyTester_ ## Key                                                                        \
+    {                                                                                               \
+        template <typename T>                                                                       \
+        static int Get(typename std::enable_if<has_nested_ ## Key<ImGuiKey_>::value, T>::type*)     \
+        {                                                                                           \
+            return ImGui::GetKeyIndex(T::Key);                                                      \
+        }                                                                                           \
+                                                                                                    \
+        template <typename T>                                                                       \
+        static int Get(typename std::enable_if<!has_nested_ ## Key<ImGuiKey_>::value, T>::type*)    \
+        {                                                                                           \
+            return -1;                                                                              \
+        }                                                                                           \
+    }
+
+DECLARE_KEY_TESTER(ImGuiKey_F);
+DECLARE_KEY_TESTER(ImGuiKey_D);
+
+static inline int GetKeyIndexForF()
+{
+    return KeyTester_ImGuiKey_F::Get<ImGuiKey_>(nullptr);
+}
+
+static inline int GetKeyIndexForD()
+{
+    return KeyTester_ImGuiKey_D::Get<ImGuiKey_>(nullptr);
+}
+
+} // namespace Detail
+} // namespace NodeEditor
+} // namespace ax
+
+
+//------------------------------------------------------------------------------
+namespace ed = ax::NodeEditor::Detail;
+
+
+//------------------------------------------------------------------------------
+static const int c_BackgroundChannelCount = 1;
+static const int c_LinkChannelCount       = 4;
+static const int c_UserLayersCount        = 5;
+
+static const int c_UserLayerChannelStart  = 0;
+static const int c_BackgroundChannelStart = c_UserLayerChannelStart  + c_UserLayersCount;
+static const int c_LinkStartChannel       = c_BackgroundChannelStart + c_BackgroundChannelCount;
+static const int c_NodeStartChannel       = c_LinkStartChannel       + c_LinkChannelCount;
+
+static const int c_BackgroundChannel_SelectionRect = c_BackgroundChannelStart + 0;
+
+static const int c_UserChannel_Content         = c_UserLayerChannelStart + 1;
+static const int c_UserChannel_Grid            = c_UserLayerChannelStart + 2;
+static const int c_UserChannel_HintsBackground = c_UserLayerChannelStart + 3;
+static const int c_UserChannel_Hints           = c_UserLayerChannelStart + 4;
+
+static const int c_LinkChannel_Selection  = c_LinkStartChannel + 0;
+static const int c_LinkChannel_Links      = c_LinkStartChannel + 1;
+static const int c_LinkChannel_Flow       = c_LinkStartChannel + 2;
+static const int c_LinkChannel_NewLink    = c_LinkStartChannel + 3;
+
+static const int c_ChannelsPerNode           = 5;
+static const int c_NodeBaseChannel           = 0;
+static const int c_NodeBackgroundChannel     = 1;
+static const int c_NodeUserBackgroundChannel = 2;
+static const int c_NodePinChannel            = 3;
+static const int c_NodeContentChannel        = 4;
+
+static const float c_GroupSelectThickness       = 6.0f;  // canvas pixels
+static const float c_LinkSelectThickness        = 5.0f;  // canvas pixels
+static const float c_NavigationZoomMargin       = 0.1f;  // percentage of visible bounds
+static const float c_MouseZoomDuration          = 0.15f; // seconds
+static const float c_SelectionFadeOutDuration   = 0.15f; // seconds
+static const auto  c_ScrollButtonIndex          = 1;
+
+
+//------------------------------------------------------------------------------
+# if defined(_DEBUG) && defined(_WIN32)
+extern "C" __declspec(dllimport) void __stdcall OutputDebugStringA(const char* string);
+
+static void LogV(const char* fmt, va_list args)
+{
+    const int buffer_size = 1024;
+    static char buffer[1024];
+
+    vsnprintf(buffer, buffer_size - 1, fmt, args);
+    buffer[buffer_size - 1] = 0;
+
+    ImGui::LogText("\nNode Editor: %s", buffer);
+
+    OutputDebugStringA("NodeEditor: ");
+    OutputDebugStringA(buffer);
+    OutputDebugStringA("\n");
+}
+# endif
+
+void ed::Log(const char* fmt, ...)
+{
+# if defined(_DEBUG) && defined(_WIN32)
+    va_list args;
+    va_start(args, fmt);
+    LogV(fmt, args);
+    va_end(args);
+# endif
+}
+
+
+//------------------------------------------------------------------------------
+static bool IsGroup(const ed::Node* node)
+{
+    if (node && node->m_Type == ed::NodeType::Group)
+        return true;
+    else
+        return false;
+}
+
+
+//------------------------------------------------------------------------------
+static void ImDrawListSplitter_Grow(ImDrawList* draw_list, ImDrawListSplitter* splitter, int channels_count)
+{
+    IM_ASSERT(splitter != nullptr);
+    IM_ASSERT(splitter->_Count <= channels_count);
+
+    if (splitter->_Count == 1)
+    {
+        splitter->Split(draw_list, channels_count);
+        return;
+    }
+
+    int old_channels_count = splitter->_Channels.Size;
+    if (old_channels_count < channels_count)
+        splitter->_Channels.resize(channels_count);
+    int old_used_channels_count = splitter->_Count;
+    splitter->_Count = channels_count;
+
+    for (int i = old_used_channels_count; i < channels_count; i++)
+    {
+        if (i >= old_channels_count)
+        {
+            IM_PLACEMENT_NEW(&splitter->_Channels[i]) ImDrawChannel();
+        }
+        else
+        {
+            splitter->_Channels[i]._CmdBuffer.resize(0);
+            splitter->_Channels[i]._IdxBuffer.resize(0);
+        }
+        if (splitter->_Channels[i]._CmdBuffer.Size == 0)
+        {
+            ImDrawCmd draw_cmd;
+            draw_cmd.ClipRect = draw_list->_ClipRectStack.back();
+            draw_cmd.TextureId = draw_list->_TextureIdStack.back();
+            splitter->_Channels[i]._CmdBuffer.push_back(draw_cmd);
+        }
+    }
+}
+
+static void ImDrawList_ChannelsGrow(ImDrawList* draw_list, int channels_count)
+{
+	ImDrawListSplitter_Grow(draw_list, &draw_list->_Splitter, channels_count);
+}
+
+static void ImDrawListSplitter_SwapChannels(ImDrawListSplitter* splitter, int left, int right)
+{
+	IM_ASSERT(left < splitter->_Count && right < splitter->_Count);
+	if (left == right)
+		return;
+
+	auto currentChannel = splitter->_Current;
+
+	auto* leftCmdBuffer  = &splitter->_Channels[left]._CmdBuffer;
+	auto* leftIdxBuffer  = &splitter->_Channels[left]._IdxBuffer;
+	auto* rightCmdBuffer = &splitter->_Channels[right]._CmdBuffer;
+	auto* rightIdxBuffer = &splitter->_Channels[right]._IdxBuffer;
+
+	leftCmdBuffer->swap(*rightCmdBuffer);
+	leftIdxBuffer->swap(*rightIdxBuffer);
+
+	if (currentChannel == left)
+		splitter->_Current = right;
+	else if (currentChannel == right)
+		splitter->_Current = left;
+}
+
+static void ImDrawList_SwapChannels(ImDrawList* drawList, int left, int right)
+{
+	ImDrawListSplitter_SwapChannels(&drawList->_Splitter, left, right);
+}
+
+static void ImDrawList_SwapSplitter(ImDrawList* drawList, ImDrawListSplitter& splitter)
+{
+    auto& currentSplitter = drawList->_Splitter;
+
+    std::swap(currentSplitter._Current, splitter._Current);
+    std::swap(currentSplitter._Count, splitter._Count);
+    currentSplitter._Channels.swap(splitter._Channels);
+}
+
+//static void ImDrawList_TransformChannel_Inner(ImVector<ImDrawVert>& vtxBuffer, const ImVector<ImDrawIdx>& idxBuffer, const ImVector<ImDrawCmd>& cmdBuffer, const ImVec2& preOffset, const ImVec2& scale, const ImVec2& postOffset)
+//{
+//    auto idxRead = idxBuffer.Data;
+//
+//    int indexOffset = 0;
+//    for (auto& cmd : cmdBuffer)
+//    {
+//        auto idxCount = cmd.ElemCount;
+//
+//        if (idxCount == 0) continue;
+//
+//        auto minIndex = idxRead[indexOffset];
+//        auto maxIndex = idxRead[indexOffset];
+//
+//        for (auto i = 1u; i < idxCount; ++i)
+//        {
+//            auto idx = idxRead[indexOffset + i];
+//            minIndex = std::min(minIndex, idx);
+//            maxIndex = ImMax(maxIndex, idx);
+//        }
+//
+//        for (auto vtx = vtxBuffer.Data + minIndex, vtxEnd = vtxBuffer.Data + maxIndex + 1; vtx < vtxEnd; ++vtx)
+//        {
+//            vtx->pos.x = (vtx->pos.x + preOffset.x) * scale.x + postOffset.x;
+//            vtx->pos.y = (vtx->pos.y + preOffset.y) * scale.y + postOffset.y;
+//        }
+//
+//        indexOffset += idxCount;
+//    }
+//}
+
+//static void ImDrawList_TransformChannels(ImDrawList* drawList, int begin, int end, const ImVec2& preOffset, const ImVec2& scale, const ImVec2& postOffset)
+//{
+//    int lastCurrentChannel = drawList->_ChannelsCurrent;
+//    if (lastCurrentChannel != 0)
+//        drawList->ChannelsSetCurrent(0);
+//
+//    auto& vtxBuffer = drawList->VtxBuffer;
+//
+//    if (begin == 0 && begin != end)
+//    {
+//        ImDrawList_TransformChannel_Inner(vtxBuffer, drawList->IdxBuffer, drawList->CmdBuffer, preOffset, scale, postOffset);
+//        ++begin;
+//    }
+//
+//    for (int channelIndex = begin; channelIndex < end; ++channelIndex)
+//    {
+//        auto& channel = drawList->_Channels[channelIndex];
+//        ImDrawList_TransformChannel_Inner(vtxBuffer, channel.IdxBuffer, channel.CmdBuffer, preOffset, scale, postOffset);
+//    }
+//
+//    if (lastCurrentChannel != 0)
+//        drawList->ChannelsSetCurrent(lastCurrentChannel);
+//}
+
+//static void ImDrawList_ClampClipRects_Inner(ImVector<ImDrawCmd>& cmdBuffer, const ImVec4& clipRect, const ImVec2& offset)
+//{
+//    for (auto& cmd : cmdBuffer)
+//    {
+//        cmd.ClipRect.x = ImMax(cmd.ClipRect.x + offset.x, clipRect.x);
+//        cmd.ClipRect.y = ImMax(cmd.ClipRect.y + offset.y, clipRect.y);
+//        cmd.ClipRect.z = std::min(cmd.ClipRect.z + offset.x, clipRect.z);
+//        cmd.ClipRect.w = std::min(cmd.ClipRect.w + offset.y, clipRect.w);
+//    }
+//}
+
+//static void ImDrawList_TranslateAndClampClipRects(ImDrawList* drawList, int begin, int end, const ImVec2& offset)
+//{
+//    int lastCurrentChannel = drawList->_ChannelsCurrent;
+//    if (lastCurrentChannel != 0)
+//        drawList->ChannelsSetCurrent(0);
+//
+//    auto clipRect = drawList->_ClipRectStack.back();
+//
+//    if (begin == 0 && begin != end)
+//    {
+//        ImDrawList_ClampClipRects_Inner(drawList->CmdBuffer, clipRect, offset);
+//        ++begin;
+//    }
+//
+//    for (int channelIndex = begin; channelIndex < end; ++channelIndex)
+//    {
+//        auto& channel = drawList->_Channels[channelIndex];
+//        ImDrawList_ClampClipRects_Inner(channel.CmdBuffer, clipRect, offset);
+//    }
+//
+//    if (lastCurrentChannel != 0)
+//        drawList->ChannelsSetCurrent(lastCurrentChannel);
+//}
+
+static void ImDrawList_PathBezierOffset(ImDrawList* drawList, float offset, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3)
+{
+    using namespace ed;
+
+    auto acceptPoint = [drawList, offset](const ImCubicBezierSubdivideSample& r)
+    {
+        drawList->PathLineTo(r.Point + ImNormalized(ImVec2(-r.Tangent.y, r.Tangent.x)) * offset);
+    };
+
+    ImCubicBezierSubdivide(acceptPoint, p0, p1, p2, p3);
+}
+
+/*
+static void ImDrawList_PolyFillScanFlood(ImDrawList *draw, std::vector<ImVec2>* poly, ImColor color, int gap = 1, float strokeWidth = 1.0f)
+{
+    std::vector<ImVec2> scanHits;
+    ImVec2 min, max; // polygon min/max points
+    auto io = ImGui::GetIO();
+    float y;
+    bool isMinMaxDone = false;
+    unsigned int polysize = poly->size();
+
+    // find the orthagonal bounding box
+    // probably can put this as a predefined
+    if (!isMinMaxDone)
+    {
+        min.x = min.y = FLT_MAX;
+        max.x = max.y = FLT_MIN;
+        for (auto p : *poly)
+        {
+            if (p.x < min.x) min.x = p.x;
+            if (p.y < min.y) min.y = p.y;
+            if (p.x > max.x) max.x = p.x;
+            if (p.y > max.y) max.y = p.y;
+        }
+        isMinMaxDone = true;
+    }
+
+    // Bounds check
+    if ((max.x < 0) || (min.x > io.DisplaySize.x) || (max.y < 0) || (min.y > io.DisplaySize.y)) return;
+
+    // Vertically clip
+    if (min.y < 0) min.y = 0;
+    if (max.y > io.DisplaySize.y) max.y = io.DisplaySize.y;
+
+    // so we know we start on the outside of the object we step out by 1.
+    min.x -= 1;
+    max.x += 1;
+
+    // Initialise our starting conditions
+    y = min.y;
+
+    // Go through each scan line iteratively, jumping by 'gap' pixels each time
+    while (y < max.y)
+    {
+        scanHits.clear();
+
+        {
+            int jump = 1;
+            ImVec2 fp = poly->at(0);
+
+            for (size_t i = 0; i < polysize - 1; i++)
+            {
+                ImVec2 pa = poly->at(i);
+                ImVec2 pb = poly->at(i + 1);
+
+                // jump double/dud points
+                if (pa.x == pb.x && pa.y == pb.y) continue;
+
+                // if we encounter our hull/poly start point, then we've now created the
+                // closed
+                // hull, jump the next segment and reset the first-point
+                if ((!jump) && (fp.x == pb.x) && (fp.y == pb.y))
+                {
+                    if (i < polysize - 2)
+                    {
+                        fp = poly->at(i + 2);
+                        jump = 1;
+                        i++;
+                    }
+                }
+                else
+                {
+                    jump = 0;
+                }
+
+                // test to see if this segment makes the scan-cut.
+                if ((pa.y > pb.y && y < pa.y && y > pb.y) || (pa.y < pb.y && y > pa.y && y < pb.y))
+                {
+                    ImVec2 intersect;
+
+                    intersect.y = y;
+                    if (pa.x == pb.x)
+                    {
+                        intersect.x = pa.x;
+                    }
+                    else
+                    {
+                        intersect.x = (pb.x - pa.x) / (pb.y - pa.y) * (y - pa.y) + pa.x;
+                    }
+                    scanHits.push_back(intersect);
+                }
+            }
+
+            // Sort the scan hits by X, so we have a proper left->right ordering
+            sort(scanHits.begin(), scanHits.end(), [](ImVec2 const &a, ImVec2 const &b) { return a.x < b.x; });
+
+            // generate the line segments.
+            {
+                int i = 0;
+                int l = scanHits.size() - 1; // we need pairs of points, this prevents segfault.
+                for (i = 0; i < l; i += 2)
+                {
+                    draw->AddLine(scanHits[i], scanHits[i + 1], color, strokeWidth);
+                }
+            }
+        }
+        y += gap;
+    } // for each scan line
+    scanHits.clear();
+}
+*/
+
+static void ImDrawList_AddBezierWithArrows(ImDrawList* drawList, const ImCubicBezierPoints& curve, float thickness,
+    float startArrowSize, float startArrowWidth, float endArrowSize, float endArrowWidth,
+    bool fill, ImU32 color, float strokeThickness)
+{
+    using namespace ax;
+
+    if ((color >> 24) == 0)
+        return;
+
+    const auto half_thickness = thickness * 0.5f;
+
+    if (fill)
+    {
+        drawList->AddBezierCurve(curve.P0, curve.P1, curve.P2, curve.P3, color, thickness);
+
+        if (startArrowSize > 0.0f)
+        {
+            const auto start_dir  = ImNormalized(ImCubicBezierTangent(curve.P0, curve.P1, curve.P2, curve.P3, 0.0f));
+            const auto start_n    = ImVec2(-start_dir.y, start_dir.x);
+            const auto half_width = startArrowWidth * 0.5f;
+            const auto tip        = curve.P0 - start_dir * startArrowSize;
+
+            drawList->PathLineTo(curve.P0 - start_n * ImMax(half_width, half_thickness));
+            drawList->PathLineTo(curve.P0 + start_n * ImMax(half_width, half_thickness));
+            drawList->PathLineTo(tip);
+            drawList->PathFillConvex(color);
+        }
+
+        if (endArrowSize > 0.0f)
+        {
+            const auto    end_dir = ImNormalized(ImCubicBezierTangent(curve.P0, curve.P1, curve.P2, curve.P3, 1.0f));
+            const auto    end_n   = ImVec2(  -end_dir.y,   end_dir.x);
+            const auto half_width = endArrowWidth * 0.5f;
+            const auto tip        = curve.P3 + end_dir * endArrowSize;
+
+            drawList->PathLineTo(curve.P3 + end_n * ImMax(half_width, half_thickness));
+            drawList->PathLineTo(curve.P3 - end_n * ImMax(half_width, half_thickness));
+            drawList->PathLineTo(tip);
+            drawList->PathFillConvex(color);
+        }
+    }
+    else
+    {
+        if (startArrowSize > 0.0f)
+        {
+            const auto start_dir  = ImNormalized(ImCubicBezierTangent(curve.P0, curve.P1, curve.P2, curve.P3, 0.0f));
+            const auto start_n    = ImVec2(-start_dir.y, start_dir.x);
+            const auto half_width = startArrowWidth * 0.5f;
+            const auto tip        = curve.P0 - start_dir * startArrowSize;
+
+            if (half_width > half_thickness)
+                drawList->PathLineTo(curve.P0 - start_n * half_width);
+            drawList->PathLineTo(tip);
+            if (half_width > half_thickness)
+                drawList->PathLineTo(curve.P0 + start_n * half_width);
+        }
+
+        ImDrawList_PathBezierOffset(drawList, half_thickness, curve.P0, curve.P1, curve.P2, curve.P3);
+
+        if (endArrowSize > 0.0f)
+        {
+            const auto    end_dir = ImNormalized(ImCubicBezierTangent(curve.P0, curve.P1, curve.P2, curve.P3, 1.0f));
+            const auto    end_n   = ImVec2(  -end_dir.y,   end_dir.x);
+            const auto half_width = endArrowWidth * 0.5f;
+            const auto tip        = curve.P3 + end_dir * endArrowSize;
+
+            if (half_width > half_thickness)
+                drawList->PathLineTo(curve.P3 + end_n * half_width);
+            drawList->PathLineTo(tip);
+            if (half_width > half_thickness)
+                drawList->PathLineTo(curve.P3 - end_n * half_width);
+        }
+
+        ImDrawList_PathBezierOffset(drawList, half_thickness, curve.P3, curve.P2, curve.P1, curve.P0);
+
+        drawList->PathStroke(color, true, strokeThickness);
+    }
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Pin
+//
+//------------------------------------------------------------------------------
+void ed::Pin::Draw(ImDrawList* drawList, DrawFlags flags)
+{
+    if (flags & Hovered)
+    {
+        drawList->ChannelsSetCurrent(m_Node->m_Channel + c_NodePinChannel);
+
+        drawList->AddRectFilled(m_Bounds.Min, m_Bounds.Max,
+            m_Color, m_Rounding, m_Corners);
+
+        if (m_BorderWidth > 0.0f)
+        {
+            FringeScaleScope fringe(1.0f);
+            drawList->AddRect(m_Bounds.Min, m_Bounds.Max,
+                m_BorderColor, m_Rounding, m_Corners, m_BorderWidth);
+        }
+
+        if (!Editor->IsSelected(m_Node))
+            m_Node->Draw(drawList, flags);
+    }
+}
+
+ImVec2 ed::Pin::GetClosestPoint(const ImVec2& p) const
+{
+    return ImRect_ClosestPoint(m_Pivot, p, true, m_Radius + m_ArrowSize);
+}
+
+ImLine ed::Pin::GetClosestLine(const Pin* pin) const
+{
+    return ImRect_ClosestLine(m_Pivot, pin->m_Pivot, m_Radius + m_ArrowSize, pin->m_Radius + pin->m_ArrowSize);
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Node
+//
+//------------------------------------------------------------------------------
+bool ed::Node::AcceptDrag()
+{
+    m_DragStart = m_Bounds.Min;
+    return true;
+}
+
+void ed::Node::UpdateDrag(const ImVec2& offset)
+{
+    auto size = m_Bounds.GetSize();
+    m_Bounds.Min = ImFloor(m_DragStart + offset);
+    m_Bounds.Max = m_Bounds.Min + size;
+}
+
+bool ed::Node::EndDrag()
+{
+    return m_Bounds.Min != m_DragStart;
+}
+
+void ed::Node::Draw(ImDrawList* drawList, DrawFlags flags)
+{
+    if (flags == Detail::Object::None)
+    {
+        drawList->ChannelsSetCurrent(m_Channel + c_NodeBackgroundChannel);
+
+        drawList->AddRectFilled(
+            m_Bounds.Min,
+            m_Bounds.Max,
+            m_Color, m_Rounding);
+
+        if (IsGroup(this))
+        {
+            drawList->AddRectFilled(
+                m_GroupBounds.Min,
+                m_GroupBounds.Max,
+                m_GroupColor, m_GroupRounding);
+
+            if (m_GroupBorderWidth > 0.0f)
+            {
+                FringeScaleScope fringe(1.0f);
+
+                drawList->AddRect(
+                    m_GroupBounds.Min,
+                    m_GroupBounds.Max,
+                    m_GroupBorderColor, m_GroupRounding, 15, m_GroupBorderWidth);
+            }
+        }
+
+# if 0
+        // #debug: highlight group regions
+        auto drawRect = [drawList](const ImRect& rect, ImU32 color)
+        {
+            if (ImRect_IsEmpty(rect)) return;
+            drawList->AddRectFilled(rect.Min, rect.Max, color);
+        };
+
+        drawRect(GetRegionBounds(NodeRegion::Top), IM_COL32(255, 0, 0, 64));
+        drawRect(GetRegionBounds(NodeRegion::Bottom), IM_COL32(255, 0, 0, 64));
+        drawRect(GetRegionBounds(NodeRegion::Left), IM_COL32(0, 255, 0, 64));
+        drawRect(GetRegionBounds(NodeRegion::Right), IM_COL32(0, 255, 0, 64));
+        drawRect(GetRegionBounds(NodeRegion::TopLeft), IM_COL32(255, 0, 255, 64));
+        drawRect(GetRegionBounds(NodeRegion::TopRight), IM_COL32(255, 0, 255, 64));
+        drawRect(GetRegionBounds(NodeRegion::BottomLeft), IM_COL32(255, 0, 255, 64));
+        drawRect(GetRegionBounds(NodeRegion::BottomRight), IM_COL32(255, 0, 255, 64));
+        drawRect(GetRegionBounds(NodeRegion::Center), IM_COL32(0, 0, 255, 64));
+        drawRect(GetRegionBounds(NodeRegion::Header), IM_COL32(0, 255, 255, 64));
+# endif
+
+        DrawBorder(drawList, m_BorderColor, m_BorderWidth);
+    }
+    else if (flags & Selected)
+    {
+        const auto  borderColor = Editor->GetColor(StyleColor_SelNodeBorder);
+        const auto& editorStyle = Editor->GetStyle();
+
+        drawList->ChannelsSetCurrent(m_Channel + c_NodeBaseChannel);
+
+        DrawBorder(drawList, borderColor, editorStyle.SelectedNodeBorderWidth);
+    }
+    else if (!IsGroup(this) && (flags & Hovered))
+    {
+        const auto  borderColor = Editor->GetColor(StyleColor_HovNodeBorder);
+        const auto& editorStyle = Editor->GetStyle();
+
+        drawList->ChannelsSetCurrent(m_Channel + c_NodeBaseChannel);
+
+        DrawBorder(drawList, borderColor, editorStyle.HoveredNodeBorderWidth);
+    }
+}
+
+void ed::Node::DrawBorder(ImDrawList* drawList, ImU32 color, float thickness)
+{
+    if (thickness > 0.0f)
+    {
+        drawList->AddRect(m_Bounds.Min, m_Bounds.Max,
+            color, m_Rounding, 15, thickness);
+    }
+}
+
+void ed::Node::GetGroupedNodes(std::vector<Node*>& result, bool append)
+{
+    if (!append)
+        result.resize(0);
+
+    if (!IsGroup(this))
+        return;
+
+    const auto firstNodeIndex = result.size();
+    Editor->FindNodesInRect(m_GroupBounds, result, true, false);
+
+    for (auto index = firstNodeIndex; index < result.size(); ++index)
+        result[index]->GetGroupedNodes(result, true);
+}
+
+ImRect ed::Node::GetRegionBounds(NodeRegion region) const
+{
+    if (m_Type == NodeType::Node)
+    {
+        if (region == NodeRegion::Header)
+            return m_Bounds;
+    }
+    else if (m_Type == NodeType::Group)
+    {
+        const float activeAreaMinimumSize = ImMax(ImMax(
+            Editor->GetView().InvScale * c_GroupSelectThickness,
+            m_GroupBorderWidth), c_GroupSelectThickness);
+        const float minimumSize = activeAreaMinimumSize * 5;
+
+        auto bounds = m_Bounds;
+        if (bounds.GetWidth() < minimumSize)
+            bounds.Expand(ImVec2(minimumSize - bounds.GetWidth(), 0.0f));
+        if (bounds.GetHeight() < minimumSize)
+            bounds.Expand(ImVec2(0.0f, minimumSize - bounds.GetHeight()));
+
+        if (region == NodeRegion::Top)
+        {
+            bounds.Max.y = bounds.Min.y + activeAreaMinimumSize;
+            bounds.Min.x += activeAreaMinimumSize;
+            bounds.Max.x -= activeAreaMinimumSize;
+            return bounds;
+        }
+        else if (region == NodeRegion::Bottom)
+        {
+            bounds.Min.y = bounds.Max.y - activeAreaMinimumSize;
+            bounds.Min.x += activeAreaMinimumSize;
+            bounds.Max.x -= activeAreaMinimumSize;
+            return bounds;
+        }
+        else if (region == NodeRegion::Left)
+        {
+            bounds.Max.x = bounds.Min.x + activeAreaMinimumSize;
+            bounds.Min.y += activeAreaMinimumSize;
+            bounds.Max.y -= activeAreaMinimumSize;
+            return bounds;
+        }
+        else if (region == NodeRegion::Right)
+        {
+            bounds.Min.x = bounds.Max.x - activeAreaMinimumSize;
+            bounds.Min.y += activeAreaMinimumSize;
+            bounds.Max.y -= activeAreaMinimumSize;
+            return bounds;
+        }
+        else if (region == NodeRegion::TopLeft)
+        {
+            bounds.Max.x = bounds.Min.x + activeAreaMinimumSize * 2;
+            bounds.Max.y = bounds.Min.y + activeAreaMinimumSize * 2;
+            return bounds;
+        }
+        else if (region == NodeRegion::TopRight)
+        {
+            bounds.Min.x = bounds.Max.x - activeAreaMinimumSize * 2;
+            bounds.Max.y = bounds.Min.y + activeAreaMinimumSize * 2;
+            return bounds;
+        }
+        else if (region == NodeRegion::BottomRight)
+        {
+            bounds.Min.x = bounds.Max.x - activeAreaMinimumSize * 2;
+            bounds.Min.y = bounds.Max.y - activeAreaMinimumSize * 2;
+            return bounds;
+        }
+        else if (region == NodeRegion::BottomLeft)
+        {
+            bounds.Max.x = bounds.Min.x + activeAreaMinimumSize * 2;
+            bounds.Min.y = bounds.Max.y - activeAreaMinimumSize * 2;
+            return bounds;
+        }
+        else if (region == NodeRegion::Header)
+        {
+            bounds.Min.x += activeAreaMinimumSize;
+            bounds.Max.x -= activeAreaMinimumSize;
+            bounds.Min.y += activeAreaMinimumSize;
+            bounds.Max.y  = ImMax(bounds.Min.y + activeAreaMinimumSize, m_GroupBounds.Min.y);
+            return bounds;
+        }
+        else if (region == NodeRegion::Center)
+        {
+            bounds.Max.x -= activeAreaMinimumSize;
+            bounds.Min.y  = ImMax(bounds.Min.y + activeAreaMinimumSize, m_GroupBounds.Min.y);
+            bounds.Min.x += activeAreaMinimumSize;
+            bounds.Max.y -= activeAreaMinimumSize;
+            return bounds;
+        }
+    }
+
+    return ImRect();
+}
+
+ed::NodeRegion ed::Node::GetRegion(const ImVec2& point) const
+{
+    if (m_Type == NodeType::Node)
+    {
+        if (m_Bounds.Contains(point))
+            return NodeRegion::Header;
+        else
+            return NodeRegion::None;
+    }
+    else if (m_Type == NodeType::Group)
+    {
+        static const NodeRegion c_Regions[] =
+        {
+            // Corners first, they may overlap other regions.
+            NodeRegion::TopLeft,
+            NodeRegion::TopRight,
+            NodeRegion::BottomLeft,
+            NodeRegion::BottomRight,
+            NodeRegion::Header,
+            NodeRegion::Top,
+            NodeRegion::Bottom,
+            NodeRegion::Left,
+            NodeRegion::Right,
+            NodeRegion::Center
+        };
+
+        for (auto region : c_Regions)
+        {
+            auto bounds = GetRegionBounds(region);
+            if (bounds.Contains(point))
+                return region;
+        }
+    }
+
+    return NodeRegion::None;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Link
+//
+//------------------------------------------------------------------------------
+void ed::Link::Draw(ImDrawList* drawList, DrawFlags flags)
+{
+    if (flags == None)
+    {
+        drawList->ChannelsSetCurrent(c_LinkChannel_Links);
+
+        Draw(drawList, m_Color, 0.0f);
+    }
+    else if (flags & Selected)
+    {
+        const auto borderColor = Editor->GetColor(StyleColor_SelLinkBorder);
+
+        drawList->ChannelsSetCurrent(c_LinkChannel_Selection);
+
+        Draw(drawList, borderColor, 4.5f);
+    }
+    else if (flags & Hovered)
+    {
+        const auto borderColor = Editor->GetColor(StyleColor_HovLinkBorder);
+
+        drawList->ChannelsSetCurrent(c_LinkChannel_Selection);
+
+        Draw(drawList, borderColor, 2.0f);
+    }
+}
+
+void ed::Link::Draw(ImDrawList* drawList, ImU32 color, float extraThickness) const
+{
+    if (!m_IsLive)
+        return;
+
+    const auto curve = GetCurve();
+
+    ImDrawList_AddBezierWithArrows(drawList, curve, m_Thickness + extraThickness,
+        m_StartPin && m_StartPin->m_ArrowSize  > 0.0f ? m_StartPin->m_ArrowSize  + extraThickness : 0.0f,
+        m_StartPin && m_StartPin->m_ArrowWidth > 0.0f ? m_StartPin->m_ArrowWidth + extraThickness : 0.0f,
+          m_EndPin &&   m_EndPin->m_ArrowSize  > 0.0f ?   m_EndPin->m_ArrowSize  + extraThickness : 0.0f,
+          m_EndPin &&   m_EndPin->m_ArrowWidth > 0.0f ?   m_EndPin->m_ArrowWidth + extraThickness : 0.0f,
+        true, color, 1.0f);
+}
+
+void ed::Link::UpdateEndpoints()
+{
+    const auto line = m_StartPin->GetClosestLine(m_EndPin);
+    m_Start = line.A;
+    m_End   = line.B;
+}
+
+ImCubicBezierPoints ed::Link::GetCurve() const
+{
+    auto easeLinkStrength = [](const ImVec2& a, const ImVec2& b, float strength)
+    {
+        const auto distanceX    = b.x - a.x;
+        const auto distanceY    = b.y - a.y;
+        const auto distance     = ImSqrt(distanceX * distanceX + distanceY * distanceY);
+        const auto halfDistance = distance * 0.5f;
+
+        if (halfDistance < strength)
+            strength = strength * ImSin(IM_PI * 0.5f * halfDistance / strength);
+
+        return strength;
+    };
+
+    const auto startStrength = easeLinkStrength(m_Start, m_End, m_StartPin->m_Strength);
+    const auto   endStrength = easeLinkStrength(m_Start, m_End,   m_EndPin->m_Strength);
+    const auto           cp0 = m_Start + m_StartPin->m_Dir * startStrength;
+    const auto           cp1 =   m_End +   m_EndPin->m_Dir *   endStrength;
+
+    ImCubicBezierPoints result;
+    result.P0 = m_Start;
+    result.P1 = cp0;
+    result.P2 = cp1;
+    result.P3 = m_End;
+
+    return result;
+}
+
+bool ed::Link::TestHit(const ImVec2& point, float extraThickness) const
+{
+    if (!m_IsLive)
+        return false;
+
+    auto bounds = GetBounds();
+    if (extraThickness > 0.0f)
+        bounds.Expand(extraThickness);
+
+    if (!bounds.Contains(point))
+        return false;
+
+    const auto bezier = GetCurve();
+    const auto result = ImProjectOnCubicBezier(point, bezier.P0, bezier.P1, bezier.P2, bezier.P3, 50);
+
+    return result.Distance <= m_Thickness + extraThickness;
+}
+
+bool ed::Link::TestHit(const ImRect& rect, bool allowIntersect) const
+{
+    if (!m_IsLive)
+        return false;
+
+    const auto bounds = GetBounds();
+
+    if (rect.Contains(bounds))
+        return true;
+
+    if (!allowIntersect || !rect.Overlaps(bounds))
+        return false;
+
+    const auto bezier = GetCurve();
+
+    const auto p0 = rect.GetTL();
+    const auto p1 = rect.GetTR();
+    const auto p2 = rect.GetBR();
+    const auto p3 = rect.GetBL();
+
+    if (ImCubicBezierLineIntersect(bezier.P0, bezier.P1, bezier.P2, bezier.P3, p0, p1).Count > 0)
+        return true;
+    if (ImCubicBezierLineIntersect(bezier.P0, bezier.P1, bezier.P2, bezier.P3, p1, p2).Count > 0)
+        return true;
+    if (ImCubicBezierLineIntersect(bezier.P0, bezier.P1, bezier.P2, bezier.P3, p2, p3).Count > 0)
+        return true;
+    if (ImCubicBezierLineIntersect(bezier.P0, bezier.P1, bezier.P2, bezier.P3, p3, p0).Count > 0)
+        return true;
+
+    return false;
+}
+
+ImRect ed::Link::GetBounds() const
+{
+    if (m_IsLive)
+    {
+        const auto curve = GetCurve();
+        auto bounds = ImCubicBezierBoundingRect(curve.P0, curve.P1, curve.P2, curve.P3);
+
+        if (bounds.GetWidth() == 0.0f)
+        {
+            bounds.Min.x -= 0.5f;
+            bounds.Max.x += 0.5f;
+        }
+
+        if (bounds.GetHeight() == 0.0f)
+        {
+            bounds.Min.y -= 0.5f;
+            bounds.Max.y += 0.5f;
+        }
+
+        if (m_StartPin->m_ArrowSize)
+        {
+            const auto start_dir = ImNormalized(ImCubicBezierTangent(curve.P0, curve.P1, curve.P2, curve.P3, 0.0f));
+            const auto p0 = curve.P0;
+            const auto p1 = curve.P0 - start_dir * m_StartPin->m_ArrowSize;
+            const auto min = ImMin(p0, p1);
+            const auto max = ImMax(p0, p1);
+            auto arrowBounds = ImRect(min, ImMax(max, min + ImVec2(1, 1)));
+            bounds.Add(arrowBounds);
+        }
+
+        if (m_EndPin->m_ArrowSize)
+        {
+            const auto end_dir = ImNormalized(ImCubicBezierTangent(curve.P0, curve.P1, curve.P2, curve.P3, 1.0f));
+            const auto p0 = curve.P3;
+            const auto p1 = curve.P3 + end_dir * m_EndPin->m_ArrowSize;
+            const auto min = ImMin(p0, p1);
+            const auto max = ImMax(p0, p1);
+            auto arrowBounds = ImRect(min, ImMax(max, min + ImVec2(1, 1)));
+            bounds.Add(arrowBounds);
+        }
+
+        return bounds;
+    }
+    else
+        return ImRect();
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Editor Context
+//
+//------------------------------------------------------------------------------
+ed::EditorContext::EditorContext(const ax::NodeEditor::Config* config)
+    : m_IsFirstFrame(true)
+    , m_IsWindowActive(false)
+    , m_ShortcutsEnabled(true)
+    , m_Style()
+    , m_Nodes()
+    , m_Pins()
+    , m_Links()
+    , m_SelectionId(1)
+    , m_LastActiveLink(nullptr)
+    , m_Canvas()
+    , m_IsCanvasVisible(false)
+    , m_NodeBuilder(this)
+    , m_HintBuilder(this)
+    , m_CurrentAction(nullptr)
+    , m_NavigateAction(this, m_Canvas)
+    , m_SizeAction(this)
+    , m_DragAction(this)
+    , m_SelectAction(this)
+    , m_ContextMenuAction(this)
+    , m_ShortcutAction(this)
+    , m_CreateItemAction(this)
+    , m_DeleteItemsAction(this)
+    , m_AnimationControllers{ &m_FlowAnimationController }
+    , m_FlowAnimationController(this)
+    , m_DoubleClickedNode(0)
+    , m_DoubleClickedPin(0)
+    , m_DoubleClickedLink(0)
+    , m_BackgroundClicked(false)
+    , m_BackgroundDoubleClicked(false)
+    , m_IsInitialized(false)
+    , m_Settings()
+    , m_Config(config)
+    , m_ExternalChannel(0)
+{
+}
+
+ed::EditorContext::~EditorContext()
+{
+    if (m_IsInitialized)
+        SaveSettings();
+
+    for (auto link  : m_Links)  delete link.m_Object;
+    for (auto pin   : m_Pins)   delete pin.m_Object;
+    for (auto node  : m_Nodes)  delete node.m_Object;
+
+    m_Splitter.ClearFreeMemory();
+}
+
+void ed::EditorContext::Begin(const char* id, const ImVec2& size)
+{
+    if (!m_IsInitialized)
+    {
+        LoadSettings();
+        m_IsInitialized = true;
+    }
+
+    //ImGui::LogToClipboard();
+    //Log("---- begin ----");
+
+    for (auto node  : m_Nodes)   node->Reset();
+    for (auto pin   : m_Pins)     pin->Reset();
+    for (auto link  : m_Links)   link->Reset();
+
+    auto drawList = ImGui::GetWindowDrawList();
+
+    ImDrawList_SwapSplitter(drawList, m_Splitter);
+    m_ExternalChannel = drawList->_Splitter._Current;
+
+    ImGui::PushID(id);
+
+    auto availableContentSize = ImGui::GetContentRegionAvail();
+    ImVec2 canvasSize = ImFloor(size);
+    if (canvasSize.x <= 0.0f)
+        canvasSize.x = ImMax(4.0f, availableContentSize.x);
+    if (canvasSize.y <= 0.0f)
+        canvasSize.y = ImMax(4.0f, availableContentSize.y);
+
+    m_IsCanvasVisible = m_Canvas.Begin(id, canvasSize);
+
+    //ImGui::PushStyleColor(ImGuiCol_ChildBg, ImVec4(0, 0, 0, 0));
+    //ImGui::BeginChild(id, size, false,
+    //    ImGuiWindowFlags_NoMove |
+    //    ImGuiWindowFlags_NoScrollbar |
+    //    ImGuiWindowFlags_NoScrollWithMouse);
+
+    ImGui::CaptureKeyboardFromApp();
+
+    m_IsWindowActive = ImGui::IsWindowFocused();
+
+    //
+	m_NavigateAction.SetWindow(m_Canvas.ViewRect().Min, m_Canvas.ViewRect().GetSize());
+
+    if (m_CurrentAction && m_CurrentAction->IsDragging() && m_NavigateAction.MoveOverEdge())
+    {
+        auto& io = ImGui::GetIO();
+        auto offset = m_NavigateAction.GetMoveOffset();
+        for (int i = 0; i < 5; ++i)
+            io.MouseClickedPos[i] = io.MouseClickedPos[i] - offset;
+    }
+    else
+        m_NavigateAction.StopMoveOverEdge();
+
+    m_Canvas.SetView(m_NavigateAction.GetView());
+
+    // #debug #clip
+    //ImGui::Text("CLIP = { x=%g y=%g w=%g h=%g r=%g b=%g }",
+    //    clipMin.x, clipMin.y, clipMax.x - clipMin.x, clipMax.y - clipMin.y, clipMax.x, clipMax.y);
+
+    // Reserve channels for background and links
+    ImDrawList_ChannelsGrow(drawList, c_NodeStartChannel);
+
+    if (HasSelectionChanged())
+        ++m_SelectionId;
+
+    m_LastSelectedObjects = m_SelectedObjects;
+}
+
+void ed::EditorContext::End()
+{
+    //auto& io          = ImGui::GetIO();
+    auto  control     = BuildControl(m_CurrentAction && m_CurrentAction->IsDragging()); // NavigateAction.IsMovingOverEdge()
+    auto  drawList    = ImGui::GetWindowDrawList();
+    //auto& editorStyle = GetStyle();
+
+    m_DoubleClickedNode       = control.DoubleClickedNode ? control.DoubleClickedNode->m_ID : 0;
+    m_DoubleClickedPin        = control.DoubleClickedPin  ? control.DoubleClickedPin->m_ID  : 0;
+    m_DoubleClickedLink       = control.DoubleClickedLink ? control.DoubleClickedLink->m_ID : 0;
+    m_BackgroundClicked       = control.BackgroundClicked;
+    m_BackgroundDoubleClicked = control.BackgroundDoubleClicked;
+
+    //if (DoubleClickedNode) LOG_TRACE(0, "DOUBLE CLICK NODE: %d", DoubleClickedNode);
+    //if (DoubleClickedPin)  LOG_TRACE(0, "DOUBLE CLICK PIN:  %d", DoubleClickedPin);
+    //if (DoubleClickedLink) LOG_TRACE(0, "DOUBLE CLICK LINK: %d", DoubleClickedLink);
+    //if (BackgroundDoubleClicked) LOG_TRACE(0, "DOUBLE CLICK BACKGROUND", DoubleClickedLink);
+
+    const bool isSelecting = m_CurrentAction && m_CurrentAction->AsSelect() != nullptr;
+    const bool isDragging  = m_CurrentAction && m_CurrentAction->AsDrag()   != nullptr;
+    //const bool isSizing    = CurrentAction && CurrentAction->AsSize()   != nullptr;
+
+    // Draw nodes
+    for (auto node : m_Nodes)
+        if (node->m_IsLive && node->IsVisible())
+            node->Draw(drawList);
+
+    // Draw links
+    for (auto link : m_Links)
+        if (link->m_IsLive && link->IsVisible())
+            link->Draw(drawList);
+
+    // Highlight selected objects
+    {
+        auto selectedObjects = &m_SelectedObjects;
+        if (auto selectAction = m_CurrentAction ? m_CurrentAction->AsSelect() : nullptr)
+            selectedObjects = &selectAction->m_CandidateObjects;
+
+        for (auto selectedObject : *selectedObjects)
+            if (selectedObject->IsVisible())
+                selectedObject->Draw(drawList, Object::Selected);
+    }
+
+    if (!isSelecting)
+    {
+        auto hoveredObject = control.HotObject;
+        if (auto dragAction = m_CurrentAction ? m_CurrentAction->AsDrag() : nullptr)
+            hoveredObject = dragAction->m_DraggedObject;
+        if (auto sizeAction = m_CurrentAction ? m_CurrentAction->AsSize() : nullptr)
+            hoveredObject = sizeAction->m_SizedNode;
+
+        if (hoveredObject && !IsSelected(hoveredObject) && hoveredObject->IsVisible())
+            hoveredObject->Draw(drawList, Object::Hovered);
+    }
+
+    // Draw animations
+    for (auto controller : m_AnimationControllers)
+        controller->Draw(drawList);
+
+    if (m_CurrentAction && !m_CurrentAction->Process(control))
+        m_CurrentAction = nullptr;
+
+    if (m_NavigateAction.m_IsActive)
+        m_NavigateAction.Process(control);
+    else
+        m_NavigateAction.Accept(control);
+
+    if (nullptr == m_CurrentAction)
+    {
+        EditorAction* possibleAction   = nullptr;
+
+        auto accept = [&possibleAction, &control](EditorAction& action)
+        {
+            auto result = action.Accept(control);
+
+            if (result == EditorAction::True)
+                return true;
+            else if (/*!possibleAction &&*/ result == EditorAction::Possible)
+                possibleAction = &action;
+            else if (result == EditorAction::Possible)
+                action.Reject();
+
+            return false;
+        };
+
+        if (accept(m_ContextMenuAction))
+            m_CurrentAction = &m_ContextMenuAction;
+        else if (accept(m_ShortcutAction))
+            m_CurrentAction = &m_ShortcutAction;
+        else if (accept(m_SizeAction))
+            m_CurrentAction = &m_SizeAction;
+        else if (accept(m_DragAction))
+            m_CurrentAction = &m_DragAction;
+        else if (accept(m_SelectAction))
+            m_CurrentAction = &m_SelectAction;
+        else if (accept(m_CreateItemAction))
+            m_CurrentAction = &m_CreateItemAction;
+        else if (accept(m_DeleteItemsAction))
+            m_CurrentAction = &m_DeleteItemsAction;
+
+        if (possibleAction)
+            ImGui::SetMouseCursor(possibleAction->GetCursor());
+
+        if (m_CurrentAction && possibleAction)
+            possibleAction->Reject();
+    }
+
+    if (m_CurrentAction)
+        ImGui::SetMouseCursor(m_CurrentAction->GetCursor());
+
+    // Draw selection rectangle
+    m_SelectAction.Draw(drawList);
+
+    bool sortGroups = false;
+    if (control.ActiveNode)
+    {
+        if (!IsGroup(control.ActiveNode))
+        {
+            // Bring active node to front
+            auto activeNodeIt = std::find(m_Nodes.begin(), m_Nodes.end(), control.ActiveNode);
+            std::rotate(activeNodeIt, activeNodeIt + 1, m_Nodes.end());
+        }
+        else if (!isDragging && m_CurrentAction && m_CurrentAction->AsDrag())
+        {
+            // Bring content of dragged group to front
+            std::vector<Node*> nodes;
+            control.ActiveNode->GetGroupedNodes(nodes);
+
+            std::stable_partition(m_Nodes.begin(), m_Nodes.end(), [&nodes](Node* node)
+            {
+                return std::find(nodes.begin(), nodes.end(), node) == nodes.end();
+            });
+
+            sortGroups = true;
+        }
+    }
+
+    // Sort nodes if bounds of node changed
+    if (sortGroups || ((m_Settings.m_DirtyReason & (SaveReasonFlags::Position | SaveReasonFlags::Size)) != SaveReasonFlags::None))
+    {
+        // Bring all groups before regular nodes
+        auto groupsItEnd = std::stable_partition(m_Nodes.begin(), m_Nodes.end(), IsGroup);
+
+        // Sort groups by area
+        std::sort(m_Nodes.begin(), groupsItEnd, [this](Node* lhs, Node* rhs)
+        {
+            const auto& lhsSize = lhs == m_SizeAction.m_SizedNode ? m_SizeAction.GetStartGroupBounds().GetSize() : lhs->m_GroupBounds.GetSize();
+            const auto& rhsSize = rhs == m_SizeAction.m_SizedNode ? m_SizeAction.GetStartGroupBounds().GetSize() : rhs->m_GroupBounds.GetSize();
+
+            const auto lhsArea = lhsSize.x * lhsSize.y;
+            const auto rhsArea = rhsSize.x * rhsSize.y;
+
+            return lhsArea > rhsArea;
+        });
+    }
+
+# if 1
+    // Every node has few channels assigned. Grow channel list
+    // to hold twice as much of channels and place them in
+    // node drawing order.
+    {
+        // Copy group nodes
+        auto liveNodeCount = static_cast<int>(std::count_if(m_Nodes.begin(), m_Nodes.end(), [](Node* node) { return node->m_IsLive; }));
+
+        // Reserve two additional channels for sorted list of channels
+        auto nodeChannelCount = drawList->_Splitter._Count;
+        ImDrawList_ChannelsGrow(drawList, drawList->_Splitter._Count + c_ChannelsPerNode * liveNodeCount + c_LinkChannelCount);
+
+        int targetChannel = nodeChannelCount;
+
+        auto copyNode = [&targetChannel, drawList](Node* node)
+        {
+            if (!node->m_IsLive)
+                return;
+
+            for (int i = 0; i < c_ChannelsPerNode; ++i)
+                ImDrawList_SwapChannels(drawList, node->m_Channel + i, targetChannel + i);
+
+            node->m_Channel = targetChannel;
+            targetChannel += c_ChannelsPerNode;
+        };
+
+        auto groupsItEnd = std::find_if(m_Nodes.begin(), m_Nodes.end(), [](Node* node) { return !IsGroup(node); });
+
+        // Copy group nodes
+        std::for_each(m_Nodes.begin(), groupsItEnd, copyNode);
+
+        // Copy links
+        for (int i = 0; i < c_LinkChannelCount; ++i, ++targetChannel)
+            ImDrawList_SwapChannels(drawList, c_LinkStartChannel + i, targetChannel);
+
+        // Copy normal nodes
+        std::for_each(groupsItEnd, m_Nodes.end(), copyNode);
+    }
+# endif
+
+    // ImGui::PopClipRect();
+
+    // Draw grid
+# if 1 // #FIXME
+    {
+        //auto& style = ImGui::GetStyle();
+
+        drawList->ChannelsSetCurrent(c_UserChannel_Grid);
+
+        ImVec2 offset    = m_Canvas.ViewOrigin() * (1.0f / m_Canvas.ViewScale());
+        ImU32 GRID_COLOR = GetColor(StyleColor_Grid, ImClamp(m_Canvas.ViewScale() * m_Canvas.ViewScale(), 0.0f, 1.0f));
+        float GRID_SX    = 32.0f;// * m_Canvas.ViewScale();
+        float GRID_SY    = 32.0f;// * m_Canvas.ViewScale();
+        ImVec2 VIEW_POS  = m_Canvas.ViewRect().Min;
+        ImVec2 VIEW_SIZE = m_Canvas.ViewRect().GetSize();
+
+        drawList->AddRectFilled(VIEW_POS, VIEW_POS + VIEW_SIZE, GetColor(StyleColor_Bg));
+
+        for (float x = fmodf(offset.x, GRID_SX); x < VIEW_SIZE.x; x += GRID_SX)
+            drawList->AddLine(ImVec2(x, 0.0f) + VIEW_POS, ImVec2(x, VIEW_SIZE.y) + VIEW_POS, GRID_COLOR);
+        for (float y = fmodf(offset.y, GRID_SY); y < VIEW_SIZE.y; y += GRID_SY)
+            drawList->AddLine(ImVec2(0.0f, y) + VIEW_POS, ImVec2(VIEW_SIZE.x, y) + VIEW_POS, GRID_COLOR);
+    }
+# endif
+
+# if 0
+    {
+        auto userChannel = drawList->_Splitter._Count;
+        auto channelsToCopy = c_UserLayersCount;
+        ImDrawList_ChannelsGrow(drawList, userChannel + channelsToCopy);
+        for (int i = 0; i < channelsToCopy; ++i)
+            ImDrawList_SwapChannels(drawList, userChannel + i, c_UserLayerChannelStart + i);
+    }
+# endif
+
+# if 0
+    {
+        auto preOffset  = ImVec2(0, 0);
+        auto postOffset = m_OldCanvas.WindowScreenPos + m_OldCanvas.ClientOrigin;
+        auto scale      = m_OldCanvas.Zoom;
+
+        ImDrawList_TransformChannels(drawList,                        0,                            1, preOffset, scale, postOffset);
+        ImDrawList_TransformChannels(drawList, c_BackgroundChannelStart, drawList->_ChannelsCount - 1, preOffset, scale, postOffset);
+
+        auto clipTranslation = m_OldCanvas.WindowScreenPos - m_OldCanvas.FromScreen(m_OldCanvas.WindowScreenPos);
+        ImGui::PushClipRect(m_OldCanvas.WindowScreenPos + ImVec2(1, 1), m_OldCanvas.WindowScreenPos + m_OldCanvas.WindowScreenSize - ImVec2(1, 1), false);
+        ImDrawList_TranslateAndClampClipRects(drawList,                        0,                            1, clipTranslation);
+        ImDrawList_TranslateAndClampClipRects(drawList, c_BackgroundChannelStart, drawList->_ChannelsCount - 1, clipTranslation);
+        ImGui::PopClipRect();
+
+        // #debug: Static grid in local space
+        //for (float x = 0; x < Canvas.WindowScreenSize.x; x += 100)
+        //    drawList->AddLine(ImVec2(x, 0.0f) + Canvas.WindowScreenPos, ImVec2(x, Canvas.WindowScreenSize.y) + Canvas.WindowScreenPos, IM_COL32(255, 0, 0, 128));
+        //for (float y = 0; y < Canvas.WindowScreenSize.y; y += 100)
+        //    drawList->AddLine(ImVec2(0.0f, y) + Canvas.WindowScreenPos, ImVec2(Canvas.WindowScreenSize.x, y) + Canvas.WindowScreenPos, IM_COL32(255, 0, 0, 128));
+    }
+# endif
+
+# if 1
+    // Move user and hint channels to top
+    {
+        // Clip plane is transformed to global space.
+        // These channels already have clip planes in global space, so
+        // we move them to clip plane. Batch transformation in canvas
+        // will bring them back to global space.
+        auto preTransformClipRect = [this, drawList](int channelIndex)
+        {
+            ImDrawChannel& channel = drawList->_Splitter._Channels[channelIndex];
+            for (ImDrawCmd& cmd : channel._CmdBuffer)
+            {
+                auto a = ToCanvas(ImVec2(cmd.ClipRect.x, cmd.ClipRect.y));
+                auto b = ToCanvas(ImVec2(cmd.ClipRect.z, cmd.ClipRect.w));
+                cmd.ClipRect = ImVec4(a.x, a.y, b.x, b.y);
+            }
+        };
+
+        drawList->ChannelsSetCurrent(0);
+
+        auto channelCount = drawList->_Splitter._Count;
+        ImDrawList_ChannelsGrow(drawList, channelCount + 3);
+        ImDrawList_SwapChannels(drawList, c_UserChannel_HintsBackground, channelCount + 0);
+        ImDrawList_SwapChannels(drawList, c_UserChannel_Hints,           channelCount + 1);
+        ImDrawList_SwapChannels(drawList, c_UserChannel_Content,         channelCount + 2);
+
+        preTransformClipRect(channelCount + 0);
+        preTransformClipRect(channelCount + 1);
+        preTransformClipRect(channelCount + 2);
+    }
+# endif
+
+    UpdateAnimations();
+
+    drawList->ChannelsMerge();
+
+    // #debug
+    // drawList->AddRectFilled(ImVec2(-10.0f, -10.0f), ImVec2(10.0f, 10.0f), IM_COL32(255, 0, 255, 255));
+
+    // ImGui::EndChild();
+    // ImGui::PopStyleColor();
+    if (m_IsCanvasVisible)
+        m_Canvas.End();
+
+    ImDrawList_SwapSplitter(drawList, m_Splitter);
+
+    // Draw border
+    {
+        auto& style = ImGui::GetStyle();
+        auto borderShadoColor = style.Colors[ImGuiCol_BorderShadow];
+        auto borderColor = style.Colors[ImGuiCol_Border];
+        drawList->AddRect(m_Canvas.Rect().Min + ImVec2(1, 1), m_Canvas.Rect().Max - ImVec2(1, 1), ImColor(borderShadoColor));
+        drawList->AddRect(m_Canvas.Rect().Min, m_Canvas.Rect().Max, ImColor(borderColor));
+    }
+
+    // ShowMetrics(control);
+
+    ImGui::PopID();
+
+    if (!m_CurrentAction && m_IsFirstFrame && !m_Settings.m_Selection.empty())
+    {
+        ClearSelection();
+        for (auto id : m_Settings.m_Selection)
+            if (auto object = FindObject(id))
+                SelectObject(object);
+    }
+
+    if (HasSelectionChanged())
+        MakeDirty(SaveReasonFlags::Selection);
+
+    if (m_Settings.m_IsDirty && !m_CurrentAction)
+        SaveSettings();
+
+    m_IsFirstFrame = false;
+}
+
+bool ed::EditorContext::DoLink(LinkId id, PinId startPinId, PinId endPinId, ImU32 color, float thickness)
+{
+    //auto& editorStyle = GetStyle();
+
+    auto startPin = FindPin(startPinId);
+    auto endPin   = FindPin(endPinId);
+
+    if (!startPin || !startPin->m_IsLive || !endPin || !endPin->m_IsLive)
+        return false;
+
+    startPin->m_HasConnection = true;
+      endPin->m_HasConnection = true;
+
+    auto link           = GetLink(id);
+    link->m_StartPin      = startPin;
+    link->m_EndPin        = endPin;
+    link->m_Color         = color;
+    link->m_Thickness     = thickness;
+    link->m_IsLive        = true;
+
+    link->UpdateEndpoints();
+
+    return true;
+}
+
+void ed::EditorContext::SetNodePosition(NodeId nodeId, const ImVec2& position)
+{
+    auto node = FindNode(nodeId);
+    if (!node)
+    {
+        node = CreateNode(nodeId);
+        node->m_IsLive = false;
+    }
+
+    if (node->m_Bounds.Min != position)
+    {
+        node->m_Bounds.Translate(position - node->m_Bounds.Min);
+        node->m_Bounds.Floor();
+        MakeDirty(NodeEditor::SaveReasonFlags::Position, node);
+    }
+}
+
+ImVec2 ed::EditorContext::GetNodePosition(NodeId nodeId)
+{
+    auto node = FindNode(nodeId);
+    if (!node)
+        return ImVec2(FLT_MAX, FLT_MAX);
+
+    return node->m_Bounds.Min;
+}
+
+ImVec2 ed::EditorContext::GetNodeSize(NodeId nodeId)
+{
+    auto node = FindNode(nodeId);
+    if (!node)
+        return ImVec2(0, 0);
+
+    return node->m_Bounds.GetSize();
+}
+
+void ed::EditorContext::MarkNodeToRestoreState(Node* node)
+{
+    node->m_RestoreState = true;
+}
+
+void ed::EditorContext::RestoreNodeState(Node* node)
+{
+    auto settings = m_Settings.FindNode(node->m_ID);
+    if (!settings)
+        return;
+
+    // Load state from config (if possible)
+    if (!NodeSettings::Parse(m_Config.LoadNode(node->m_ID), *settings))
+        return;
+
+    node->m_Bounds.Min      = settings->m_Location;
+    node->m_Bounds.Max      = node->m_Bounds.Min + settings->m_Size;
+    node->m_Bounds.Floor();
+    node->m_GroupBounds.Min = settings->m_Location;
+    node->m_GroupBounds.Max = node->m_GroupBounds.Min + settings->m_GroupSize;
+    node->m_GroupBounds.Floor();
+}
+
+void ed::EditorContext::ClearSelection()
+{
+    m_SelectedObjects.clear();
+}
+
+void ed::EditorContext::SelectObject(Object* object)
+{
+    m_SelectedObjects.push_back(object);
+}
+
+void ed::EditorContext::DeselectObject(Object* object)
+{
+    auto objectIt = std::find(m_SelectedObjects.begin(), m_SelectedObjects.end(), object);
+    if (objectIt != m_SelectedObjects.end())
+        m_SelectedObjects.erase(objectIt);
+}
+
+void ed::EditorContext::SetSelectedObject(Object* object)
+{
+    ClearSelection();
+    SelectObject(object);
+}
+
+void ed::EditorContext::ToggleObjectSelection(Object* object)
+{
+    if (IsSelected(object))
+        DeselectObject(object);
+    else
+        SelectObject(object);
+}
+
+bool ed::EditorContext::IsSelected(Object* object)
+{
+    return std::find(m_SelectedObjects.begin(), m_SelectedObjects.end(), object) != m_SelectedObjects.end();
+}
+
+const ed::vector<ed::Object*>& ed::EditorContext::GetSelectedObjects()
+{
+    return m_SelectedObjects;
+}
+
+bool ed::EditorContext::IsAnyNodeSelected()
+{
+    for (auto object : m_SelectedObjects)
+        if (object->AsNode())
+            return true;
+
+    return false;
+}
+
+bool ed::EditorContext::IsAnyLinkSelected()
+{
+    for (auto object : m_SelectedObjects)
+        if (object->AsLink())
+            return true;
+
+    return false;
+}
+
+bool ed::EditorContext::HasSelectionChanged()
+{
+    return m_LastSelectedObjects != m_SelectedObjects;
+}
+
+ed::Node* ed::EditorContext::FindNodeAt(const ImVec2& p)
+{
+    for (auto node : m_Nodes)
+        if (node->TestHit(p))
+            return node;
+
+    return nullptr;
+}
+
+void ed::EditorContext::FindNodesInRect(const ImRect& r, vector<Node*>& result, bool append, bool includeIntersecting)
+{
+    if (!append)
+        result.resize(0);
+
+    if (ImRect_IsEmpty(r))
+        return;
+
+    for (auto node : m_Nodes)
+        if (node->TestHit(r, includeIntersecting))
+            result.push_back(node);
+}
+
+void ed::EditorContext::FindLinksInRect(const ImRect& r, vector<Link*>& result, bool append)
+{
+    if (!append)
+        result.resize(0);
+
+    if (ImRect_IsEmpty(r))
+        return;
+
+    for (auto link : m_Links)
+        if (link->TestHit(r))
+            result.push_back(link);
+}
+
+void ed::EditorContext::FindLinksForNode(NodeId nodeId, vector<Link*>& result, bool add)
+{
+    if (!add)
+        result.clear();
+
+    for (auto link : m_Links)
+    {
+        if (!link->m_IsLive)
+            continue;
+
+        if (link->m_StartPin->m_Node->m_ID == nodeId || link->m_EndPin->m_Node->m_ID == nodeId)
+            result.push_back(link);
+    }
+}
+
+bool ed::EditorContext::PinHadAnyLinks(PinId pinId)
+{
+    auto pin = FindPin(pinId);
+    if (!pin || !pin->m_IsLive)
+        return false;
+
+    return pin->m_HasConnection || pin->m_HadConnection;
+}
+
+void ed::EditorContext::NotifyLinkDeleted(Link* link)
+{
+    if (m_LastActiveLink == link)
+        m_LastActiveLink = nullptr;
+}
+
+void ed::EditorContext::Suspend(SuspendFlags flags)
+{
+    auto drawList = ImGui::GetWindowDrawList();
+    auto lastChannel = drawList->_Splitter._Current;
+    drawList->ChannelsSetCurrent(m_ExternalChannel);
+    m_Canvas.Suspend();
+    drawList->ChannelsSetCurrent(lastChannel);
+    if ((flags & SuspendFlags::KeepSplitter) != SuspendFlags::KeepSplitter)
+        ImDrawList_SwapSplitter(drawList, m_Splitter);
+}
+
+void ed::EditorContext::Resume(SuspendFlags flags)
+{
+    auto drawList = ImGui::GetWindowDrawList();
+    if ((flags & SuspendFlags::KeepSplitter) != SuspendFlags::KeepSplitter)
+        ImDrawList_SwapSplitter(drawList, m_Splitter);
+    auto lastChannel = drawList->_Splitter._Current;
+    drawList->ChannelsSetCurrent(m_ExternalChannel);
+    m_Canvas.Resume();
+    drawList->ChannelsSetCurrent(lastChannel);
+}
+
+bool ed::EditorContext::IsSuspended()
+{
+	return m_Canvas.IsSuspended();
+}
+
+bool ed::EditorContext::IsActive()
+{
+    return m_IsWindowActive;
+}
+
+ed::Pin* ed::EditorContext::CreatePin(PinId id, PinKind kind)
+{
+    IM_ASSERT(nullptr == FindObject(id));
+    auto pin = new Pin(this, id, kind);
+    m_Pins.push_back({id, pin});
+    std::sort(m_Pins.begin(), m_Pins.end());
+    return pin;
+}
+
+ed::Node* ed::EditorContext::CreateNode(NodeId id)
+{
+    IM_ASSERT(nullptr == FindObject(id));
+    auto node = new Node(this, id);
+    m_Nodes.push_back({id, node});
+    //std::sort(Nodes.begin(), Nodes.end());
+
+    auto settings = m_Settings.FindNode(id);
+    if (!settings)
+        settings = m_Settings.AddNode(id);
+
+    if (!settings->m_WasUsed)
+    {
+        settings->m_WasUsed = true;
+        RestoreNodeState(node);
+    }
+
+    node->m_Bounds.Min  = settings->m_Location;
+    node->m_Bounds.Max  = node->m_Bounds.Min;
+    node->m_Bounds.Floor();
+
+    if (settings->m_GroupSize.x > 0 || settings->m_GroupSize.y > 0)
+    {
+        node->m_Type            = NodeType::Group;
+        node->m_GroupBounds.Min = settings->m_Location;
+        node->m_GroupBounds.Max = node->m_GroupBounds.Min + settings->m_GroupSize;
+        node->m_GroupBounds.Floor();
+    }
+
+    node->m_IsLive = false;
+
+    return node;
+}
+
+ed::Link* ed::EditorContext::CreateLink(LinkId id)
+{
+    IM_ASSERT(nullptr == FindObject(id));
+    auto link = new Link(this, id);
+    m_Links.push_back({id, link});
+    std::sort(m_Links.begin(), m_Links.end());
+
+    return link;
+}
+
+template <typename C, typename Id>
+static inline auto FindItemInLinear(C& container, Id id)
+{
+# if defined(_DEBUG)
+    auto start = container.data();
+    auto end   = container.data() + container.size();
+    for (auto it = start; it < end; ++it)
+        if ((*it).m_ID == id)
+            return it->m_Object;
+# else
+    for (auto item : container)
+        if (item.m_ID == id)
+            return item.m_Object;
+# endif
+
+   return static_cast<decltype(container[0].m_Object)>(nullptr);
+}
+
+template <typename C, typename Id>
+static inline auto FindItemIn(C& container, Id id)
+{
+//# if defined(_DEBUG)
+//    auto start = container.data();
+//    auto end   = container.data() + container.size();
+//    for (auto it = start; it < end; ++it)
+//        if ((*it)->ID == id)
+//            return *it;
+//# else
+//    for (auto item : container)
+//        if (item->ID == id)
+//            return item;
+//# endif
+    auto key = typename C::value_type{ id, nullptr };
+    auto first = container.cbegin();
+    auto last  = container.cend();
+    auto it    = std::lower_bound(first, last, key);
+    if (it != last && (key.m_ID == it->m_ID))
+        return it->m_Object;
+    else
+        return static_cast<decltype(it->m_Object)>(nullptr);
+}
+
+ed::Node* ed::EditorContext::FindNode(NodeId id)
+{
+    return FindItemInLinear(m_Nodes, id);
+}
+
+ed::Pin* ed::EditorContext::FindPin(PinId id)
+{
+    return FindItemIn(m_Pins, id);
+}
+
+ed::Link* ed::EditorContext::FindLink(LinkId id)
+{
+    return FindItemIn(m_Links, id);
+}
+
+ed::Object* ed::EditorContext::FindObject(ObjectId id)
+{
+    if (id.IsNodeId())
+        return FindNode(id.AsNodeId());
+    else if (id.IsLinkId())
+        return FindLink(id.AsLinkId());
+    else if (id.IsPinId())
+        return FindPin(id.AsPinId());
+    else
+        return nullptr;
+}
+
+ed::Node* ed::EditorContext::GetNode(NodeId id)
+{
+    auto node = FindNode(id);
+    if (!node)
+        node = CreateNode(id);
+    return node;
+}
+
+ed::Pin* ed::EditorContext::GetPin(PinId id, PinKind kind)
+{
+    if (auto pin = FindPin(id))
+    {
+        pin->m_Kind = kind;
+        return pin;
+    }
+    else
+        return CreatePin(id, kind);
+}
+
+ed::Link* ed::EditorContext::GetLink(LinkId id)
+{
+    if (auto link = FindLink(id))
+        return link;
+    else
+        return CreateLink(id);
+}
+
+void ed::EditorContext::LoadSettings()
+{
+    ed::Settings::Parse(m_Config.Load(), m_Settings);
+
+    m_NavigateAction.m_Scroll = m_Settings.m_ViewScroll;
+    m_NavigateAction.m_Zoom   = m_Settings.m_ViewZoom;
+}
+
+void ed::EditorContext::SaveSettings()
+{
+    m_Config.BeginSave();
+
+    for (auto& node : m_Nodes)
+    {
+        auto settings = m_Settings.FindNode(node->m_ID);
+        settings->m_Location = node->m_Bounds.Min;
+        settings->m_Size     = node->m_Bounds.GetSize();
+        if (IsGroup(node))
+            settings->m_GroupSize = node->m_GroupBounds.GetSize();
+
+        if (!node->m_RestoreState && settings->m_IsDirty && m_Config.SaveNodeSettings)
+        {
+            if (m_Config.SaveNode(node->m_ID, settings->Serialize().dump(), settings->m_DirtyReason))
+                settings->ClearDirty();
+        }
+    }
+
+    m_Settings.m_Selection.resize(0);
+    for (auto& object : m_SelectedObjects)
+        m_Settings.m_Selection.push_back(object->ID());
+
+    m_Settings.m_ViewScroll = m_NavigateAction.m_Scroll;
+    m_Settings.m_ViewZoom   = m_NavigateAction.m_Zoom;
+
+    if (m_Config.Save(m_Settings.Serialize(), m_Settings.m_DirtyReason))
+        m_Settings.ClearDirty();
+
+    m_Config.EndSave();
+}
+
+void ed::EditorContext::MakeDirty(SaveReasonFlags reason)
+{
+    m_Settings.MakeDirty(reason);
+}
+
+void ed::EditorContext::MakeDirty(SaveReasonFlags reason, Node* node)
+{
+    m_Settings.MakeDirty(reason, node);
+}
+
+ed::Link* ed::EditorContext::FindLinkAt(const ImVec2& p)
+{
+    for (auto& link : m_Links)
+        if (link->TestHit(p, c_LinkSelectThickness))
+            return link;
+
+    return nullptr;
+}
+
+ImU32 ed::EditorContext::GetColor(StyleColor colorIndex) const
+{
+    return ImColor(m_Style.Colors[colorIndex]);
+}
+
+ImU32 ed::EditorContext::GetColor(StyleColor colorIndex, float alpha) const
+{
+    auto color = m_Style.Colors[colorIndex];
+    return ImColor(color.x, color.y, color.z, color.w * alpha);
+}
+
+void ed::EditorContext::RegisterAnimation(Animation* animation)
+{
+    m_LiveAnimations.push_back(animation);
+}
+
+void ed::EditorContext::UnregisterAnimation(Animation* animation)
+{
+    auto it = std::find(m_LiveAnimations.begin(), m_LiveAnimations.end(), animation);
+    if (it != m_LiveAnimations.end())
+        m_LiveAnimations.erase(it);
+}
+
+void ed::EditorContext::UpdateAnimations()
+{
+    m_LastLiveAnimations = m_LiveAnimations;
+
+    for (auto animation : m_LastLiveAnimations)
+    {
+        const bool isLive = (std::find(m_LiveAnimations.begin(), m_LiveAnimations.end(), animation) != m_LiveAnimations.end());
+
+        if (isLive)
+            animation->Update();
+    }
+}
+
+void ed::EditorContext::Flow(Link* link)
+{
+    m_FlowAnimationController.Flow(link);
+}
+
+void ed::EditorContext::SetUserContext(bool globalSpace)
+{
+    const auto mousePos = ImGui::GetMousePos();
+
+    // Move drawing cursor to mouse location and prepare layer for
+    // content added by user.
+    if (globalSpace)
+        ImGui::SetCursorScreenPos(m_Canvas.FromLocal(mousePos));
+    else
+        ImGui::SetCursorScreenPos(m_Canvas.FromLocal(mousePos));
+        //ImGui::SetCursorScreenPos(ImFloor(mousePos));
+        //ImGui::SetCursorScreenPos(ImVec2(floorf(mousePos.x), floorf(mousePos.y)));
+
+    if (!IsSuspended())
+    {
+        auto drawList = ImGui::GetWindowDrawList();
+        drawList->ChannelsSetCurrent(c_UserChannel_Content);
+    }
+
+    // #debug
+    // drawList->AddCircleFilled(ImGui::GetMousePos(), 4, IM_COL32(0, 255, 0, 255));
+}
+
+void ed::EditorContext::EnableShortcuts(bool enable)
+{
+    m_ShortcutsEnabled = enable;
+}
+
+bool ed::EditorContext::AreShortcutsEnabled()
+{
+    return m_ShortcutsEnabled;
+}
+
+ed::Control ed::EditorContext::BuildControl(bool allowOffscreen)
+{
+    if (!allowOffscreen && !ImGui::IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem))
+        return Control(nullptr, nullptr, nullptr, nullptr, false, false, false, false);
+
+    const auto mousePos = ImGui::GetMousePos();
+
+    // Expand clip rectangle to always contain cursor
+    auto editorRect = m_Canvas.ViewRect();
+    auto isMouseOffscreen = allowOffscreen && !editorRect.Contains(mousePos);
+    if (isMouseOffscreen)
+    {
+        // Extend clip rect to capture off-screen mouse cursor
+        editorRect.Add(ImFloor(mousePos));
+        editorRect.Add(ImVec2(ImCeil(mousePos.x), ImCeil(mousePos.y)));
+
+        ImGui::PushClipRect(editorRect.Min, editorRect.Max, false);
+    }
+
+    Object* hotObject           = nullptr;
+    Object* activeObject        = nullptr;
+    Object* clickedObject       = nullptr;
+    Object* doubleClickedObject = nullptr;
+
+    // Emits invisible button and returns true if it is clicked.
+    auto emitInteractiveArea = [](ObjectId id, const ImRect& rect)
+    {
+        char idString[33] = { 0 }; // itoa can output 33 bytes maximum
+        snprintf(idString, 32, "%p", id.AsPointer());
+        ImGui::SetCursorScreenPos(rect.Min);
+
+        // debug
+        //if (id < 0) return ImGui::Button(idString, to_imvec(rect.size));
+
+        auto result = ImGui::InvisibleButton(idString, rect.GetSize());
+
+        // #debug
+        //ImGui::GetWindowDrawList()->AddRectFilled(ImGui::GetItemRectMin(), ImGui::GetItemRectMax(), IM_COL32(0, 255, 0, 64));
+
+        return result;
+    };
+
+    // Check input interactions over area.
+    auto checkInteractionsInArea = [&emitInteractiveArea, &hotObject, &activeObject, &clickedObject, &doubleClickedObject](ObjectId id, const ImRect& rect, Object* object)
+    {
+        if (emitInteractiveArea(id, rect))
+            clickedObject = object;
+        if (!doubleClickedObject && ImGui::IsMouseDoubleClicked(0) && ImGui::IsItemHovered())
+            doubleClickedObject = object;
+
+        if (!hotObject && ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem))
+            hotObject = object;
+
+        if (ImGui::IsItemActive())
+            activeObject = object;
+    };
+
+    // Process live nodes and pins.
+    for (auto nodeIt = m_Nodes.rbegin(), nodeItEnd = m_Nodes.rend(); nodeIt != nodeItEnd; ++nodeIt)
+    {
+        auto node = *nodeIt;
+
+        if (!node->m_IsLive) continue;
+
+        // Check for interactions with live pins in node before
+        // processing node itself. Pins does not overlap each other
+        // and all are within node bounds.
+        for (auto pin = node->m_LastPin; pin; pin = pin->m_PreviousPin)
+        {
+            if (!pin->m_IsLive) continue;
+
+            checkInteractionsInArea(pin->m_ID, pin->m_Bounds, pin);
+        }
+
+        // Check for interactions with node.
+        if (node->m_Type == NodeType::Group)
+        {
+            // Node with a hole
+            ImGui::PushID(node->m_ID.AsPointer());
+
+            static const NodeRegion c_Regions[] =
+            {
+                NodeRegion::TopLeft,
+                NodeRegion::TopRight,
+                NodeRegion::BottomLeft,
+                NodeRegion::BottomRight,
+                NodeRegion::Top,
+                NodeRegion::Bottom,
+                NodeRegion::Left,
+                NodeRegion::Right,
+                NodeRegion::Header,
+            };
+
+            for (auto region : c_Regions)
+            {
+                auto bounds = node->GetRegionBounds(region);
+                if (ImRect_IsEmpty(bounds))
+                    continue;
+                checkInteractionsInArea(NodeId(static_cast<int>(region)), bounds, node);
+            }
+
+            ImGui::PopID();
+        }
+        else
+            checkInteractionsInArea(node->m_ID, node->m_Bounds, node);
+    }
+
+    // Links are not regular widgets and must be done manually since
+    // ImGui does not support interactive elements with custom hit maps.
+    //
+    // Links can steal input from background.
+
+    // Links are just over background. So if anything else
+    // is hovered we can skip them.
+    if (nullptr == hotObject)
+        hotObject = FindLinkAt(mousePos);
+
+    // Check for interaction with background.
+    auto backgroundClicked       = emitInteractiveArea(NodeId(0), editorRect);
+    auto backgroundDoubleClicked = !doubleClickedObject && ImGui::IsItemHovered() ? ImGui::IsMouseDoubleClicked(0) : false;
+    auto isBackgroundActive      = ImGui::IsItemActive();
+    auto isBackgroundHot         = !hotObject;
+    auto isDragging              = ImGui::IsMouseDragging(0, 1) || ImGui::IsMouseDragging(1, 1) || ImGui::IsMouseDragging(2, 1);
+
+    if (backgroundDoubleClicked)
+        backgroundClicked = false;
+
+    if (isMouseOffscreen)
+        ImGui::PopClipRect();
+
+    // Process link input using background interactions.
+    auto hotLink = hotObject ? hotObject->AsLink() : nullptr;
+
+    // ImGui take care of tracking active items. With link
+    // we must do this ourself.
+    if (!isDragging && isBackgroundActive && hotLink && !m_LastActiveLink)
+        m_LastActiveLink = hotLink;
+    if (isBackgroundActive && m_LastActiveLink)
+    {
+        activeObject       = m_LastActiveLink;
+        isBackgroundActive = false;
+    }
+    else if (!isBackgroundActive && m_LastActiveLink)
+        m_LastActiveLink = nullptr;
+
+    // Steal click from backgrounds if link is hovered.
+    if (!isDragging && backgroundClicked && hotLink)
+    {
+        clickedObject     = hotLink;
+        backgroundClicked = false;
+    }
+
+    // Steal double-click from backgrounds if link is hovered.
+    if (!isDragging && backgroundDoubleClicked && hotLink)
+    {
+        doubleClickedObject = hotLink;
+        backgroundDoubleClicked = false;
+    }
+
+    return Control(hotObject, activeObject, clickedObject, doubleClickedObject,
+        isBackgroundHot, isBackgroundActive, backgroundClicked, backgroundDoubleClicked);
+}
+
+void ed::EditorContext::ShowMetrics(const Control& control)
+{
+    auto& io = ImGui::GetIO();
+
+    auto getObjectName = [](Object* object)
+    {
+        if (!object) return "";
+        else if (object->AsNode())  return "Node";
+        else if (object->AsPin())   return "Pin";
+        else if (object->AsLink())  return "Link";
+        else return "";
+    };
+
+    auto getHotObjectName = [&control, &getObjectName]()
+    {
+        if (control.HotObject)
+            return getObjectName(control.HotObject);
+        else if (control.BackgroundHot)
+            return "Background";
+        else
+            return "<unknown>";
+    };
+
+    auto getActiveObjectName = [&control, &getObjectName]()
+    {
+        if (control.ActiveObject)
+            return getObjectName(control.ActiveObject);
+        else if (control.BackgroundActive)
+            return "Background";
+        else
+            return "<unknown>";
+    };
+
+    auto liveNodeCount  = (int)std::count_if(m_Nodes.begin(),  m_Nodes.end(),  [](Node*  node)  { return  node->m_IsLive; });
+    auto livePinCount   = (int)std::count_if(m_Pins.begin(),   m_Pins.end(),   [](Pin*   pin)   { return   pin->m_IsLive; });
+    auto liveLinkCount  = (int)std::count_if(m_Links.begin(),  m_Links.end(),  [](Link*  link)  { return  link->m_IsLive; });
+
+    auto canvasRect     = m_Canvas.Rect();
+    auto viewRect       = m_Canvas.ViewRect();
+    auto localMousePos  = m_Canvas.ToLocal(io.MousePos);
+    auto globalMousePos = io.MousePos;
+
+    ImGui::SetCursorScreenPos(canvasRect.Min + ImVec2(5, 5));
+    ImGui::BeginGroup();
+    ImGui::Text("Is Editor Active: %s", ImGui::IsWindowHovered() ? "true" : "false");
+    ImGui::Text("View Position: { x=%g y=%g }", viewRect.Min.x, viewRect.Min.y);
+    ImGui::Text("View Size: { w=%g h=%g }", viewRect.GetWidth(), viewRect.GetHeight());
+    ImGui::Text("Canvas Size: { w=%g h=%g }", canvasRect.GetWidth(), canvasRect.GetHeight());
+    ImGui::Text("Mouse: { x=%.0f y=%.0f } global: { x=%g y=%g }", localMousePos.x, localMousePos.y, globalMousePos.x, globalMousePos.y);
+    ImGui::Text("Live Nodes: %d", liveNodeCount);
+    ImGui::Text("Live Pins: %d", livePinCount);
+    ImGui::Text("Live Links: %d", liveLinkCount);
+    ImGui::Text("Hot Object: %s (%p)", getHotObjectName(), control.HotObject ? control.HotObject->ID().AsPointer() : nullptr);
+    if (auto node = control.HotObject ? control.HotObject->AsNode() : nullptr)
+    {
+        ImGui::SameLine();
+        ImGui::Text("{ x=%g y=%g w=%g h=%g }", node->m_Bounds.Min.x, node->m_Bounds.Min.y, node->m_Bounds.GetWidth(), node->m_Bounds.GetHeight());
+    }
+    ImGui::Text("Active Object: %s (%p)", getActiveObjectName(), control.ActiveObject ? control.ActiveObject->ID().AsPointer() : nullptr);
+    if (auto node = control.ActiveObject ? control.ActiveObject->AsNode() : nullptr)
+    {
+        ImGui::SameLine();
+        ImGui::Text("{ x=%g y=%g w=%g h=%g }", node->m_Bounds.Min.x, node->m_Bounds.Min.y, node->m_Bounds.GetWidth(), node->m_Bounds.GetHeight());
+    }
+    ImGui::Text("Action: %s", m_CurrentAction ? m_CurrentAction->GetName() : "<none>");
+    ImGui::Text("Action Is Dragging: %s", m_CurrentAction && m_CurrentAction->IsDragging() ? "Yes" : "No");
+    m_NavigateAction.ShowMetrics();
+    m_SizeAction.ShowMetrics();
+    m_DragAction.ShowMetrics();
+    m_SelectAction.ShowMetrics();
+    m_ContextMenuAction.ShowMetrics();
+    m_CreateItemAction.ShowMetrics();
+    m_DeleteItemsAction.ShowMetrics();
+    ImGui::EndGroup();
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Node Settings
+//
+//------------------------------------------------------------------------------
+void ed::NodeSettings::ClearDirty()
+{
+    m_IsDirty     = false;
+    m_DirtyReason = SaveReasonFlags::None;
+}
+
+void ed::NodeSettings::MakeDirty(SaveReasonFlags reason)
+{
+    m_IsDirty     = true;
+    m_DirtyReason = m_DirtyReason | reason;
+}
+
+ed::json::value ed::NodeSettings::Serialize()
+{
+    json::value result;
+    result["location"]["x"] = m_Location.x;
+    result["location"]["y"] = m_Location.y;
+
+    if (m_GroupSize.x > 0 || m_GroupSize.y > 0)
+    {
+        result["group_size"]["x"] = m_GroupSize.x;
+        result["group_size"]["y"] = m_GroupSize.y;
+    }
+
+    return result;
+}
+
+bool ed::NodeSettings::Parse(const std::string& string, NodeSettings& settings)
+{
+    auto settingsValue = json::value::parse(string);
+    if (settingsValue.is_discarded())
+        return false;
+
+    return Parse(settingsValue, settings);
+}
+
+bool ed::NodeSettings::Parse(const json::value& data, NodeSettings& result)
+{
+    if (!data.is_object())
+        return false;
+
+    auto tryParseVector = [](const json::value& v, ImVec2& result) -> bool
+    {
+        if (v.is_object())
+        {
+            auto xValue = v["x"];
+            auto yValue = v["y"];
+
+            if (xValue.is_number() && yValue.is_number())
+            {
+                result.x = static_cast<float>(xValue.get<double>());
+                result.y = static_cast<float>(yValue.get<double>());
+
+                return true;
+            }
+        }
+
+        return false;
+    };
+
+    if (!tryParseVector(data["location"], result.m_Location))
+        return false;
+
+    if (data.contains("group_size") && !tryParseVector(data["group_size"], result.m_GroupSize))
+        return false;
+
+    return true;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Settings
+//
+//------------------------------------------------------------------------------
+ed::NodeSettings* ed::Settings::AddNode(NodeId id)
+{
+    m_Nodes.push_back(NodeSettings(id));
+    return &m_Nodes.back();
+}
+
+ed::NodeSettings* ed::Settings::FindNode(NodeId id)
+{
+    for (auto& settings : m_Nodes)
+        if (settings.m_ID == id)
+            return &settings;
+
+    return nullptr;
+}
+
+void ed::Settings::ClearDirty(Node* node)
+{
+    if (node)
+    {
+        auto settings = FindNode(node->m_ID);
+        IM_ASSERT(settings);
+        settings->ClearDirty();
+    }
+    else
+    {
+        m_IsDirty     = false;
+        m_DirtyReason = SaveReasonFlags::None;
+
+        for (auto& knownNode : m_Nodes)
+            knownNode.ClearDirty();
+    }
+}
+
+void ed::Settings::MakeDirty(SaveReasonFlags reason, Node* node)
+{
+    m_IsDirty     = true;
+    m_DirtyReason = m_DirtyReason | reason;
+
+    if (node)
+    {
+        auto settings = FindNode(node->m_ID);
+        IM_ASSERT(settings);
+
+        settings->MakeDirty(reason);
+    }
+}
+
+std::string ed::Settings::Serialize()
+{
+    json::value result;
+
+    auto serializeObjectId = [](ObjectId id)
+    {
+        auto value = std::to_string(reinterpret_cast<uintptr_t>(id.AsPointer()));
+        switch (id.Type())
+        {
+            default:
+            case NodeEditor::Detail::ObjectType::None: return value;
+            case NodeEditor::Detail::ObjectType::Node: return "node:" + value;
+            case NodeEditor::Detail::ObjectType::Link: return "link:" + value;
+            case NodeEditor::Detail::ObjectType::Pin:  return "pin:"  + value;
+        }
+    };
+
+    auto& nodes = result["nodes"];
+    for (auto& node : m_Nodes)
+    {
+        if (node.m_WasUsed)
+            nodes[serializeObjectId(node.m_ID)] = node.Serialize();
+    }
+
+    auto& selection = result["selection"];
+    for (auto& id : m_Selection)
+        selection.push_back(serializeObjectId(id));
+
+    auto& view = result["view"];
+    view["scroll"]["x"] = m_ViewScroll.x;
+    view["scroll"]["y"] = m_ViewScroll.y;
+    view["zoom"]   = m_ViewZoom;
+
+    return result.dump();
+}
+
+bool ed::Settings::Parse(const std::string& string, Settings& settings)
+{
+    Settings result = settings;
+
+    auto settingsValue = json::value::parse(string);
+    if (settingsValue.is_discarded())
+        return false;
+
+    if (!settingsValue.is_object())
+        return false;
+
+    auto tryParseVector = [](const json::value& v, ImVec2& result) -> bool
+    {
+        if (v.is_object() && v.contains("x") && v.contains("y"))
+        {
+            auto xValue = v["x"];
+            auto yValue = v["y"];
+
+            if (xValue.is_number() && yValue.is_number())
+            {
+                result.x = static_cast<float>(xValue.get<double>());
+                result.y = static_cast<float>(yValue.get<double>());
+
+                return true;
+            }
+        }
+
+        return false;
+    };
+
+    auto deserializeObjectId = [](const std::string& str)
+    {
+        auto separator = str.find_first_of(':');
+        auto idStart   = str.c_str() + ((separator != std::string::npos) ? separator + 1 : 0);
+        auto id        = reinterpret_cast<void*>(strtoull(idStart, nullptr, 10));
+        if (str.compare(0, separator, "node") == 0)
+            return ObjectId(NodeId(id));
+        else if (str.compare(0, separator, "link") == 0)
+            return ObjectId(LinkId(id));
+        else if (str.compare(0, separator, "pin") == 0)
+            return ObjectId(PinId(id));
+        else
+            // fallback to old format
+            return ObjectId(NodeId(id)); //return ObjectId();
+    };
+
+    //auto& settingsObject = settingsValue.get<json::object>();
+
+    auto& nodesValue = settingsValue["nodes"];
+    if (nodesValue.is_object())
+    {
+        for (auto& node : nodesValue.get<json::object>())
+        {
+            auto id = deserializeObjectId(node.first.c_str()).AsNodeId();
+
+            auto nodeSettings = result.FindNode(id);
+            if (!nodeSettings)
+                nodeSettings = result.AddNode(id);
+
+            NodeSettings::Parse(node.second, *nodeSettings);
+        }
+    }
+
+    auto& selectionValue = settingsValue["selection"];
+    if (selectionValue.is_array())
+    {
+        const auto selectionArray = selectionValue.get<json::array>();
+
+        result.m_Selection.reserve(selectionArray.size());
+        result.m_Selection.resize(0);
+        for (auto& selection : selectionArray)
+        {
+            if (selection.is_string())
+                result.m_Selection.push_back(deserializeObjectId(selection.get<json::string>()));
+        }
+    }
+
+    auto& viewValue = settingsValue["view"];
+    if (viewValue.is_object())
+    {
+        auto& viewScrollValue = viewValue["scroll"];
+        auto& viewZoomValue   = viewValue["zoom"];
+
+        if (!tryParseVector(viewScrollValue, result.m_ViewScroll))
+            result.m_ViewScroll = ImVec2(0, 0);
+
+        result.m_ViewZoom = viewZoomValue.is_number() ? static_cast<float>(viewZoomValue.get<double>()) : 1.0f;
+    }
+
+    settings = std::move(result);
+
+    return true;
+}
+
+
+
+//------------------------------------------------------------------------------
+//
+// Animation
+//
+//------------------------------------------------------------------------------
+ed::Animation::Animation(EditorContext* editor):
+    Editor(editor),
+    m_State(Stopped),
+    m_Time(0.0f),
+    m_Duration(0.0f)
+{
+}
+
+ed::Animation::~Animation()
+{
+    Stop();
+}
+
+void ed::Animation::Play(float duration)
+{
+    if (IsPlaying())
+        Stop();
+
+    m_State = Playing;
+    if (duration < 0)
+        duration = 0.0f;
+
+    m_Time     = 0.0f;
+    m_Duration = duration;
+
+    OnPlay();
+
+    Editor->RegisterAnimation(this);
+
+    if (duration == 0.0f)
+        Stop();
+}
+
+void ed::Animation::Stop()
+{
+    if (!IsPlaying())
+        return;
+
+    m_State = Stopped;
+
+    Editor->UnregisterAnimation(this);
+
+    OnStop();
+}
+
+void ed::Animation::Finish()
+{
+    if (!IsPlaying())
+        return;
+
+    OnFinish();
+
+    Stop();
+}
+
+void ed::Animation::Update()
+{
+    if (!IsPlaying())
+        return;
+
+    m_Time += ImMax(0.0f, ImGui::GetIO().DeltaTime);
+    if (m_Time < m_Duration)
+    {
+        const float progress = GetProgress();
+        OnUpdate(progress);
+    }
+    else
+    {
+        OnFinish();
+        Stop();
+    }
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Navigate Animation
+//
+//------------------------------------------------------------------------------
+ed::NavigateAnimation::NavigateAnimation(EditorContext* editor, NavigateAction& scrollAction):
+    Animation(editor),
+    Action(scrollAction)
+{
+}
+
+void ed::NavigateAnimation::NavigateTo(const ImRect& target, float duration)
+{
+    Stop();
+
+    m_Start      = Action.GetViewRect();
+    m_Target     = target;
+
+    // Skip tiny animations
+    auto minoffset = m_Target.Min - m_Start.Min;
+    auto maxOffset = m_Target.Max - m_Start.Max;
+    auto epsilon   = 1e-4f;
+    if (ImFabs(minoffset.x) < epsilon && ImFabs(minoffset.y) < epsilon &&
+        ImFabs(maxOffset.x) < epsilon && ImFabs(maxOffset.y) < epsilon)
+    {
+        duration = 0;
+    }
+
+    Play(duration);
+}
+
+void ed::NavigateAnimation::OnUpdate(float progress)
+{
+    ImRect current;
+    current.Min = ImEasing::EaseOutQuad(m_Start.Min, m_Target.Min - m_Start.Min, progress);
+    current.Max = ImEasing::EaseOutQuad(m_Start.Max, m_Target.Max - m_Start.Max, progress);
+    Action.SetViewRect(current);
+}
+
+void ed::NavigateAnimation::OnStop()
+{
+    Editor->MakeDirty(SaveReasonFlags::Navigation);
+}
+
+void ed::NavigateAnimation::OnFinish()
+{
+    Action.SetViewRect(m_Target);
+
+    Editor->MakeDirty(SaveReasonFlags::Navigation);
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Flow Animation
+//
+//------------------------------------------------------------------------------
+ed::FlowAnimation::FlowAnimation(FlowAnimationController* controller):
+    Animation(controller->Editor),
+    Controller(controller),
+    m_Link(nullptr),
+    m_Offset(0.0f),
+    m_PathLength(0.0f)
+{
+}
+
+void ed::FlowAnimation::Flow(ed::Link* link, float markerDistance, float speed, float duration)
+{
+    Stop();
+
+    if (m_Link != link)
+    {
+        m_Offset = 0.0f;
+        ClearPath();
+    }
+
+    if (m_MarkerDistance != markerDistance)
+        ClearPath();
+
+    m_MarkerDistance = markerDistance;
+    m_Speed          = speed;
+    m_Link           = link;
+
+    Play(duration);
+}
+
+void ed::FlowAnimation::Draw(ImDrawList* drawList)
+{
+    if (!IsPlaying() || !IsLinkValid() || !m_Link->IsVisible())
+        return;
+
+    if (!IsPathValid())
+        UpdatePath();
+
+    m_Offset = fmodf(m_Offset, m_MarkerDistance);
+
+    const auto progress    = GetProgress();
+
+    const auto flowAlpha = 1.0f - progress * progress;
+    const auto flowColor = Editor->GetColor(StyleColor_Flow, flowAlpha);
+    //const auto flowPath  = Link->GetCurve();
+
+    m_Link->Draw(drawList, flowColor, 2.0f);
+
+    if (IsPathValid())
+    {
+        //Offset = 0;
+
+        const auto markerAlpha  = powf(1.0f - progress, 0.35f);
+        const auto markerRadius = 4.0f * (1.0f - progress) + 2.0f;
+        const auto markerColor  = Editor->GetColor(StyleColor_FlowMarker, markerAlpha);
+
+        for (float d = m_Offset; d < m_PathLength; d += m_MarkerDistance)
+            drawList->AddCircleFilled(SamplePath(d), markerRadius, markerColor);
+    }
+}
+
+bool ed::FlowAnimation::IsLinkValid() const
+{
+    return m_Link && m_Link->m_IsLive;
+}
+
+bool ed::FlowAnimation::IsPathValid() const
+{
+    return m_Path.size() > 1 && m_PathLength > 0.0f && m_Link->m_Start == m_LastStart && m_Link->m_End == m_LastEnd;
+}
+
+void ed::FlowAnimation::UpdatePath()
+{
+    if (!IsLinkValid())
+    {
+        ClearPath();
+        return;
+    }
+
+    const auto curve  = m_Link->GetCurve();
+
+    m_LastStart  = m_Link->m_Start;
+    m_LastEnd    = m_Link->m_End;
+    m_PathLength = ImCubicBezierLength(curve.P0, curve.P1, curve.P2, curve.P3);
+
+    auto collectPointsCallback = [this](ImCubicBezierFixedStepSample& result)
+    {
+        m_Path.push_back(CurvePoint{ result.Length, result.Point });
+    };
+
+    const auto step = ImMax(m_MarkerDistance * 0.5f, 15.0f);
+
+    m_Path.resize(0);
+    ImCubicBezierFixedStep(collectPointsCallback, curve, step, false, 0.5f, 0.001f);
+}
+
+void ed::FlowAnimation::ClearPath()
+{
+    vector<CurvePoint>().swap(m_Path);
+    m_PathLength = 0.0f;
+}
+
+ImVec2 ed::FlowAnimation::SamplePath(float distance)
+{
+    //distance = ImMax(0.0f, std::min(distance, PathLength));
+
+    auto endPointIt = std::find_if(m_Path.begin(), m_Path.end(), [distance](const CurvePoint& p) { return distance < p.Distance; });
+    if (endPointIt == m_Path.end())
+        endPointIt = m_Path.end() - 1;
+    else if (endPointIt == m_Path.begin())
+        endPointIt = m_Path.begin() + 1;
+
+    const auto& start = endPointIt[-1];
+    const auto& end   = *endPointIt;
+    const auto  t     = (distance - start.Distance) / (end.Distance - start.Distance);
+
+    return start.Point + (end.Point - start.Point) * t;
+}
+
+void ed::FlowAnimation::OnUpdate(float progress)
+{
+    IM_UNUSED(progress);
+
+    m_Offset += m_Speed * ImGui::GetIO().DeltaTime;
+}
+
+void ed::FlowAnimation::OnStop()
+{
+    Controller->Release(this);
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Flow Animation Controller
+//
+//------------------------------------------------------------------------------
+ed::FlowAnimationController::FlowAnimationController(EditorContext* editor):
+    AnimationController(editor)
+{
+}
+
+ed::FlowAnimationController::~FlowAnimationController()
+{
+    for (auto animation : m_Animations)
+        delete animation;
+}
+
+void ed::FlowAnimationController::Flow(Link* link)
+{
+    if (!link || !link->m_IsLive)
+        return;
+
+    auto& editorStyle = GetStyle();
+
+    auto animation = GetOrCreate(link);
+
+    animation->Flow(link, editorStyle.FlowMarkerDistance, editorStyle.FlowSpeed, editorStyle.FlowDuration);
+}
+
+void ed::FlowAnimationController::Draw(ImDrawList* drawList)
+{
+    if (m_Animations.empty())
+        return;
+
+    drawList->ChannelsSetCurrent(c_LinkChannel_Flow);
+
+    for (auto animation : m_Animations)
+        animation->Draw(drawList);
+}
+
+ed::FlowAnimation* ed::FlowAnimationController::GetOrCreate(Link* link)
+{
+    // Return live animation which match target link
+    {
+        auto animationIt = std::find_if(m_Animations.begin(), m_Animations.end(), [link](FlowAnimation* animation) { return animation->m_Link == link; });
+        if (animationIt != m_Animations.end())
+            return *animationIt;
+    }
+
+    // There are no live animations for target link, try to reuse inactive old one
+    if (!m_FreePool.empty())
+    {
+        auto animation = m_FreePool.back();
+        m_FreePool.pop_back();
+        return animation;
+    }
+
+    // Cache miss, allocate new one
+    auto animation = new FlowAnimation(this);
+    m_Animations.push_back(animation);
+
+    return animation;
+}
+
+void ed::FlowAnimationController::Release(FlowAnimation* animation)
+{
+    IM_UNUSED(animation);
+}
+
+
+
+//------------------------------------------------------------------------------
+//
+// Navigate Action
+//
+//------------------------------------------------------------------------------
+const float ed::NavigateAction::s_ZoomLevels[] =
+{
+    0.1f, 0.15f, 0.20f, 0.25f, 0.33f, 0.5f, 0.75f, 1.0f, 1.25f, 1.50f, 2.0f, 2.5f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f
+};
+
+const int ed::NavigateAction::s_ZoomLevelCount = sizeof(s_ZoomLevels) / sizeof(*s_ZoomLevels);
+
+ed::NavigateAction::NavigateAction(EditorContext* editor, ImGuiEx::Canvas& canvas):
+    EditorAction(editor),
+    m_IsActive(false),
+    m_Zoom(1),
+    m_Scroll(0, 0),
+    m_ScrollStart(0, 0),
+    m_ScrollDelta(0, 0),
+    m_Canvas(canvas),
+    m_WindowScreenPos(0, 0),
+    m_WindowScreenSize(0, 0),
+    m_Animation(editor, *this),
+    m_Reason(NavigationReason::Unknown),
+    m_LastSelectionId(0),
+    m_LastObject(nullptr),
+    m_MovingOverEdge(false),
+    m_MoveOffset(0, 0)
+{
+}
+
+ed::EditorAction::AcceptResult ed::NavigateAction::Accept(const Control& control)
+{
+    IM_ASSERT(!m_IsActive);
+
+    if (m_IsActive)
+        return False;
+
+    if (ImGui::IsWindowHovered() /*&& !ImGui::IsAnyItemActive()*/ && ImGui::IsMouseDragging(c_ScrollButtonIndex, 0.0f))
+    {
+        m_IsActive    = true;
+        m_ScrollStart = m_Scroll;
+        m_ScrollDelta = ImGui::GetMouseDragDelta(c_ScrollButtonIndex);
+        m_Scroll      = m_ScrollStart - m_ScrollDelta * m_Zoom;
+    }
+
+    auto& io = ImGui::GetIO();
+
+    if (ImGui::IsWindowFocused() && ImGui::IsKeyPressed(GetKeyIndexForF()) && Editor->AreShortcutsEnabled())
+    {
+        const auto allowZoomIn = io.KeyShift;
+
+        auto findHotObjectToZoom = [this, &control, &io]() -> Object*
+        {
+            if (control.HotObject)
+            {
+                if (auto pin = control.HotObject->AsPin())
+                    return pin->m_Node;
+                else
+                    return control.HotObject;
+            }
+            else if (control.BackgroundHot)
+            {
+                auto node = Editor->FindNodeAt(io.MousePos);
+                if (IsGroup(node))
+                    return node;
+            }
+
+            return nullptr;
+        };
+
+        bool navigateToContent = false;
+        if (!Editor->GetSelectedObjects().empty())
+        {
+            if (m_Reason != NavigationReason::Selection || m_LastSelectionId != Editor->GetSelectionId() || allowZoomIn)
+            {
+                m_LastSelectionId = Editor->GetSelectionId();
+                NavigateTo(Editor->GetSelectionBounds(), allowZoomIn, -1.0f, NavigationReason::Selection);
+            }
+            else
+                navigateToContent = true;
+        }
+        else if(auto hotObject = findHotObjectToZoom())
+        {
+            if (m_Reason != NavigationReason::Object || m_LastObject != hotObject || allowZoomIn)
+            {
+                m_LastObject = hotObject;
+                auto bounds = hotObject->GetBounds();
+                NavigateTo(bounds, allowZoomIn, -1.0f, NavigationReason::Object);
+            }
+            else
+                navigateToContent = true;
+        }
+        else
+            navigateToContent = true;
+
+        if (navigateToContent)
+            NavigateTo(Editor->GetContentBounds(), true, -1.0f, NavigationReason::Content);
+    }
+
+    // // #debug
+    // if (auto drawList = ImGui::GetWindowDrawList())
+    //     drawList->AddCircleFilled(io.MousePos, 4.0f, IM_COL32(255, 0, 255, 255));
+
+    if (HandleZoom(control))
+        return True;
+
+    return m_IsActive ? True : False;
+}
+
+bool ed::NavigateAction::Process(const Control& control)
+{
+    IM_UNUSED(control);
+
+    if (!m_IsActive)
+        return false;
+
+    if (ImGui::IsMouseDragging(c_ScrollButtonIndex, 0.0f))
+    {
+        m_ScrollDelta = ImGui::GetMouseDragDelta(c_ScrollButtonIndex);
+        m_Scroll      = m_ScrollStart - m_ScrollDelta * m_Zoom;
+
+//         if (IsActive && Animation.IsPlaying())
+//             Animation.Target = Animation.Target - ScrollDelta * Animation.TargetZoom;
+    }
+    else
+    {
+        if (m_Scroll != m_ScrollStart)
+            Editor->MakeDirty(SaveReasonFlags::Navigation);
+
+        m_IsActive = false;
+    }
+
+    // #TODO: Handle zoom while scrolling
+    // HandleZoom(control);
+
+    return m_IsActive;
+}
+
+bool ed::NavigateAction::HandleZoom(const Control& control)
+{
+    IM_UNUSED(control);
+
+    const auto currentAction  = Editor->GetCurrentAction();
+    const auto allowOffscreen = currentAction && currentAction->IsDragging();
+
+    auto& io = ImGui::GetIO();
+
+    if (!io.MouseWheel || (!allowOffscreen && !ImGui::IsWindowHovered()))// && !ImGui::IsAnyItemActive())
+        return false;
+
+    auto savedScroll = m_Scroll;
+    auto savedZoom   = m_Zoom;
+
+    m_Animation.Finish();
+
+    auto mousePos = io.MousePos;
+    auto steps    = (int)io.MouseWheel;
+    auto newZoom  = MatchZoom(steps, s_ZoomLevels[steps < 0 ? 0 : s_ZoomLevelCount - 1]);
+
+    auto oldView   = GetView();
+    m_Zoom = newZoom;
+    auto newView   = GetView();
+
+    auto screenPos = m_Canvas.FromLocal(mousePos, oldView);
+    auto canvasPos = m_Canvas.ToLocal(screenPos, newView);
+
+    auto offset       = (canvasPos - mousePos) * m_Zoom;
+    auto targetScroll = m_Scroll - offset;
+
+    if (m_Scroll != savedScroll || m_Zoom != savedZoom)
+    {
+        m_Scroll = savedScroll;
+        m_Zoom = savedZoom;
+
+        Editor->MakeDirty(SaveReasonFlags::Navigation);
+    }
+
+    auto targetRect = m_Canvas.CalcViewRect(ImGuiEx::CanvasView(-targetScroll, newZoom));
+
+    NavigateTo(targetRect, c_MouseZoomDuration, NavigationReason::MouseZoom);
+
+    return true;
+}
+
+void ed::NavigateAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Active: %s", m_IsActive ? "yes" : "no");
+    ImGui::Text("    Scroll: { x=%g y=%g }", m_Scroll.x, m_Scroll.y);
+    ImGui::Text("    Zoom: %g", m_Zoom);
+}
+
+void ed::NavigateAction::NavigateTo(const ImRect& bounds, bool zoomIn, float duration, NavigationReason reason)
+{
+    if (ImRect_IsEmpty(bounds))
+        return;
+
+    if (duration < 0.0f)
+        duration = GetStyle().ScrollDuration;
+
+    if (!zoomIn)
+    {
+        auto viewRect       = m_Canvas.ViewRect();
+        auto viewRectCenter = viewRect.GetCenter();
+        auto targetCenter   = bounds.GetCenter();
+
+        viewRect.Translate(targetCenter - viewRectCenter);
+
+        NavigateTo(viewRect, duration, reason);
+    }
+    else
+    {
+        // Grow rect by 5% to leave some reasonable margin
+        // from the edges of the canvas.
+        auto rect   = bounds;
+        auto extend = ImMax(rect.GetWidth(), rect.GetHeight());
+        rect.Expand(extend * c_NavigationZoomMargin * 0.5f);
+
+        NavigateTo(rect, duration, reason);
+    }
+}
+
+void ed::NavigateAction::NavigateTo(const ImRect& target, float duration, NavigationReason reason)
+{
+    m_Reason = reason;
+
+    m_Animation.NavigateTo(target, duration);
+}
+
+void ed::NavigateAction::StopNavigation()
+{
+    m_Animation.Stop();
+}
+
+void ed::NavigateAction::FinishNavigation()
+{
+    m_Animation.Finish();
+}
+
+bool ed::NavigateAction::MoveOverEdge()
+{
+    // Don't interrupt non-edge animations
+    if (m_Animation.IsPlaying())
+        return false;
+
+          auto& io            = ImGui::GetIO();
+    const auto screenRect     = m_Canvas.ViewRect();
+    const auto screenMousePos = io.MousePos;
+
+    // Mouse is over screen, do nothing
+    if (screenRect.Contains(screenMousePos))
+        return false;
+
+    const auto screenPointOnEdge = ImRect_ClosestPoint(screenRect, screenMousePos, true);
+    const auto direction         = screenPointOnEdge - screenMousePos;
+    const auto offset            = -direction * io.DeltaTime * 10.0f;
+
+    m_Scroll = m_Scroll + offset;
+
+    m_MoveOffset     = offset;
+    m_MovingOverEdge = true;
+
+    return true;
+}
+
+void ed::NavigateAction::StopMoveOverEdge()
+{
+    if (m_MovingOverEdge)
+    {
+        Editor->MakeDirty(SaveReasonFlags::Navigation);
+
+        m_MoveOffset     = ImVec2(0, 0);
+        m_MovingOverEdge = false;
+    }
+}
+
+void ed::NavigateAction::SetWindow(ImVec2 position, ImVec2 size)
+{
+    m_WindowScreenPos  = position;
+    m_WindowScreenSize = size;
+}
+
+ImGuiEx::CanvasView ed::NavigateAction::GetView() const
+{
+    return ImGuiEx::CanvasView(-m_Scroll, m_Zoom);
+}
+
+ImVec2 ed::NavigateAction::GetViewOrigin() const
+{
+    return -m_Scroll;
+}
+
+float ed::NavigateAction::GetViewScale() const
+{
+    return m_Zoom;
+}
+
+void ed::NavigateAction::SetViewRect(const ImRect& rect)
+{
+    auto view = m_Canvas.CalcCenterView(rect);
+    m_Scroll = -view.Origin;
+    m_Zoom   =  view.Scale;
+}
+
+ImRect ed::NavigateAction::GetViewRect() const
+{
+    return m_Canvas.CalcViewRect(GetView());
+}
+
+float ed::NavigateAction::MatchZoom(int steps, float fallbackZoom)
+{
+    auto currentZoomIndex = MatchZoomIndex(steps);
+    if (currentZoomIndex < 0)
+        return fallbackZoom;
+
+    auto currentZoom = s_ZoomLevels[currentZoomIndex];
+    if (fabsf(currentZoom - m_Zoom) > 0.001f)
+        return currentZoom;
+
+    auto newIndex = currentZoomIndex + steps;
+    if (newIndex >= 0 && newIndex < s_ZoomLevelCount)
+        return s_ZoomLevels[newIndex];
+    else
+        return fallbackZoom;
+}
+
+int ed::NavigateAction::MatchZoomIndex(int direction)
+{
+    int   bestIndex    = -1;
+    float bestDistance = 0.0f;
+
+    for (int i = 0; i < s_ZoomLevelCount; ++i)
+    {
+        auto distance = fabsf(s_ZoomLevels[i] - m_Zoom);
+        if (distance < bestDistance || bestIndex < 0)
+        {
+            bestDistance = distance;
+            bestIndex    = i;
+        }
+    }
+
+    if (bestDistance > 0.001f)
+    {
+        if (direction > 0)
+        {
+            ++bestIndex;
+
+            if (bestIndex >= s_ZoomLevelCount)
+                bestIndex = s_ZoomLevelCount - 1;
+        }
+        else if (direction < 0)
+        {
+            --bestIndex;
+
+            if (bestIndex < 0)
+                bestIndex = 0;
+        }
+    }
+
+    return bestIndex;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Size Action
+//
+//------------------------------------------------------------------------------
+ed::SizeAction::SizeAction(EditorContext* editor):
+    EditorAction(editor),
+    m_IsActive(false),
+    m_Clean(false),
+    m_SizedNode(nullptr),
+    m_Pivot(NodeRegion::None),
+    m_Cursor(ImGuiMouseCursor_Arrow)
+{
+}
+
+ed::EditorAction::AcceptResult ed::SizeAction::Accept(const Control& control)
+{
+    IM_ASSERT(!m_IsActive);
+
+    if (m_IsActive)
+        return False;
+
+    if (control.ActiveNode && IsGroup(control.ActiveNode) && ImGui::IsMouseDragging(0, 0))
+    {
+        //const auto mousePos     = to_point(ImGui::GetMousePos());
+        //const auto closestPoint = control.ActiveNode->Bounds.get_closest_point_hollow(mousePos, static_cast<int>(control.ActiveNode->Rounding));
+
+        auto pivot = GetRegion(control.ActiveNode);
+        if (pivot != NodeRegion::Header && pivot != NodeRegion::Center)
+        {
+            m_StartBounds      = control.ActiveNode->m_Bounds;
+            m_StartGroupBounds = control.ActiveNode->m_GroupBounds;
+            m_LastSize         = control.ActiveNode->m_Bounds.GetSize();
+            m_MinimumSize      = ImVec2(0, 0);
+            m_LastDragOffset   = ImVec2(0, 0);
+            m_Pivot            = pivot;
+            m_Cursor           = ChooseCursor(m_Pivot);
+            m_SizedNode        = control.ActiveNode;
+            m_IsActive         = true;
+        }
+    }
+    else if (control.HotNode && IsGroup(control.HotNode))
+    {
+        m_Cursor = ChooseCursor(GetRegion(control.HotNode));
+        return Possible;
+    }
+
+    return m_IsActive ? True : False;
+}
+
+bool ed::SizeAction::Process(const Control& control)
+{
+    if (m_Clean)
+    {
+        m_Clean = false;
+
+        if (m_SizedNode->m_Bounds.Min != m_StartBounds.Min || m_SizedNode->m_GroupBounds.Min != m_StartGroupBounds.Min)
+            Editor->MakeDirty(SaveReasonFlags::Position | SaveReasonFlags::User, m_SizedNode);
+
+        if (m_SizedNode->m_Bounds.GetSize() != m_StartBounds.GetSize() || m_SizedNode->m_GroupBounds.GetSize() != m_StartGroupBounds.GetSize())
+            Editor->MakeDirty(SaveReasonFlags::Size | SaveReasonFlags::User, m_SizedNode);
+
+        m_SizedNode = nullptr;
+    }
+
+    if (!m_IsActive)
+        return false;
+
+    if (control.ActiveNode == m_SizedNode)
+    {
+        const auto dragOffset = (control.ActiveNode == m_SizedNode) ? ImGui::GetMouseDragDelta(0, 0.0f) : m_LastDragOffset;
+        m_LastDragOffset = dragOffset;
+
+        if (m_MinimumSize.x == 0.0f && m_LastSize.x != m_SizedNode->m_Bounds.GetWidth())
+            m_MinimumSize.x = m_SizedNode->m_Bounds.GetWidth();
+        if (m_MinimumSize.y == 0.0f && m_LastSize.y != m_SizedNode->m_Bounds.GetHeight())
+            m_MinimumSize.y = m_SizedNode->m_Bounds.GetHeight();
+
+        auto minimumSize = ImMax(m_MinimumSize, m_StartBounds.GetSize() - m_StartGroupBounds.GetSize());
+
+
+        auto newBounds = m_StartBounds;
+
+        if ((m_Pivot & NodeRegion::Top) == NodeRegion::Top)
+            newBounds.Min.y = ImMin(newBounds.Max.y - minimumSize.y, Editor->AlignPointToGrid(newBounds.Min.y + dragOffset.y));
+        if ((m_Pivot & NodeRegion::Bottom) == NodeRegion::Bottom)
+            newBounds.Max.y = ImMax(newBounds.Min.y + minimumSize.y, Editor->AlignPointToGrid(newBounds.Max.y + dragOffset.y));
+        if ((m_Pivot & NodeRegion::Left) == NodeRegion::Left)
+            newBounds.Min.x = ImMin(newBounds.Max.x - minimumSize.x, Editor->AlignPointToGrid(newBounds.Min.x + dragOffset.x));
+        if ((m_Pivot & NodeRegion::Right) == NodeRegion::Right)
+            newBounds.Max.x = ImMax(newBounds.Min.x + minimumSize.x, Editor->AlignPointToGrid(newBounds.Max.x + dragOffset.x));
+
+        newBounds.Floor();
+
+        m_LastSize = newBounds.GetSize();
+
+        m_SizedNode->m_Bounds      = newBounds;
+        m_SizedNode->m_GroupBounds = newBounds;
+        m_SizedNode->m_GroupBounds.Min.x -= m_StartBounds.Min.x - m_StartGroupBounds.Min.x;
+        m_SizedNode->m_GroupBounds.Min.y -= m_StartBounds.Min.y - m_StartGroupBounds.Min.y;
+        m_SizedNode->m_GroupBounds.Max.x -= m_StartBounds.Max.x - m_StartGroupBounds.Max.x;
+        m_SizedNode->m_GroupBounds.Max.y -= m_StartBounds.Max.y - m_StartGroupBounds.Max.y;
+    }
+    else if (!control.ActiveNode)
+    {
+        m_Clean = true;
+        m_IsActive = false;
+        return true;
+    }
+
+    return m_IsActive;
+}
+
+void ed::SizeAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    auto getObjectName = [](Object* object)
+    {
+        if (!object) return "";
+        else if (object->AsNode())  return "Node";
+        else if (object->AsPin())   return "Pin";
+        else if (object->AsLink())  return "Link";
+        else return "";
+    };
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Active: %s", m_IsActive ? "yes" : "no");
+    ImGui::Text("    Node: %s (%p)", getObjectName(m_SizedNode), m_SizedNode ? m_SizedNode->m_ID.AsPointer() : nullptr);
+    if (m_SizedNode && m_IsActive)
+    {
+        ImGui::Text("    Bounds: { x=%g y=%g w=%g h=%g }", m_SizedNode->m_Bounds.Min.x, m_SizedNode->m_Bounds.Min.y, m_SizedNode->m_Bounds.GetWidth(), m_SizedNode->m_Bounds.GetHeight());
+        ImGui::Text("    Group Bounds: { x=%g y=%g w=%g h=%g }", m_SizedNode->m_GroupBounds.Min.x, m_SizedNode->m_GroupBounds.Min.y, m_SizedNode->m_GroupBounds.GetWidth(), m_SizedNode->m_GroupBounds.GetHeight());
+        ImGui::Text("    Start Bounds: { x=%g y=%g w=%g h=%g }", m_StartBounds.Min.x, m_StartBounds.Min.y, m_StartBounds.GetWidth(), m_StartBounds.GetHeight());
+        ImGui::Text("    Start Group Bounds: { x=%g y=%g w=%g h=%g }", m_StartGroupBounds.Min.x, m_StartGroupBounds.Min.y, m_StartGroupBounds.GetWidth(), m_StartGroupBounds.GetHeight());
+        ImGui::Text("    Minimum Size: { w=%g h=%g }", m_MinimumSize.x, m_MinimumSize.y);
+        ImGui::Text("    Last Size: { w=%g h=%g }", m_LastSize.x, m_LastSize.y);
+    }
+}
+
+ed::NodeRegion ed::SizeAction::GetRegion(Node* node)
+{
+    return node->GetRegion(ImGui::GetMousePos());
+}
+
+ImGuiMouseCursor ed::SizeAction::ChooseCursor(NodeRegion region)
+{
+    switch (region)
+    {
+        default:
+        case NodeRegion::Center:
+            return ImGuiMouseCursor_Arrow;
+
+        case NodeRegion::Top:
+        case NodeRegion::Bottom:
+            return ImGuiMouseCursor_ResizeNS;
+
+        case NodeRegion::Left:
+        case NodeRegion::Right:
+            return ImGuiMouseCursor_ResizeEW;
+
+        case NodeRegion::TopLeft:
+        case NodeRegion::BottomRight:
+            return ImGuiMouseCursor_ResizeNWSE;
+
+        case NodeRegion::TopRight:
+        case NodeRegion::BottomLeft:
+            return ImGuiMouseCursor_ResizeNESW;
+    }
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Drag Action
+//
+//------------------------------------------------------------------------------
+ed::DragAction::DragAction(EditorContext* editor):
+    EditorAction(editor),
+    m_IsActive(false),
+    m_Clear(false),
+    m_DraggedObject(nullptr)
+{
+}
+
+ed::EditorAction::AcceptResult ed::DragAction::Accept(const Control& control)
+{
+    IM_ASSERT(!m_IsActive);
+
+    if (m_IsActive)
+        return False;
+
+    if (control.ActiveObject && ImGui::IsMouseDragging(0))
+    {
+        if (!control.ActiveObject->AcceptDrag())
+            return False;
+
+        m_DraggedObject = control.ActiveObject;
+
+        m_Objects.resize(0);
+        m_Objects.push_back(m_DraggedObject);
+
+        if (Editor->IsSelected(m_DraggedObject))
+        {
+            for (auto selectedObject : Editor->GetSelectedObjects())
+                if (auto selectedNode = selectedObject->AsNode())
+                    if (selectedNode != m_DraggedObject && selectedNode->AcceptDrag())
+                        m_Objects.push_back(selectedNode);
+        }
+
+        auto& io = ImGui::GetIO();
+        if (!io.KeyShift)
+        {
+            std::vector<Node*> groupedNodes;
+            for (auto object : m_Objects)
+                if (auto node = object->AsNode())
+                    node->GetGroupedNodes(groupedNodes, true);
+
+            auto isAlreadyPicked = [this](Node* node)
+            {
+                return std::find(m_Objects.begin(), m_Objects.end(), node) != m_Objects.end();
+            };
+
+            for (auto candidate : groupedNodes)
+                if (!isAlreadyPicked(candidate) && candidate->AcceptDrag())
+                    m_Objects.push_back(candidate);
+        }
+
+        m_IsActive = true;
+    }
+    else if (control.HotNode && IsGroup(control.HotNode) && control.HotNode->GetRegion(ImGui::GetMousePos()) == NodeRegion::Header)
+    {
+        return Possible;
+    }
+
+    return m_IsActive ? True : False;
+}
+
+bool ed::DragAction::Process(const Control& control)
+{
+    if (m_Clear)
+    {
+        m_Clear = false;
+
+        for (auto object : m_Objects)
+        {
+            if (object->EndDrag())
+                Editor->MakeDirty(SaveReasonFlags::Position | SaveReasonFlags::User, object->AsNode());
+        }
+
+        m_Objects.resize(0);
+
+        m_DraggedObject = nullptr;
+    }
+
+    if (!m_IsActive)
+        return false;
+
+    if (control.ActiveObject == m_DraggedObject)
+    {
+        auto dragOffset = ImGui::GetMouseDragDelta(0, 0.0f);
+
+        auto draggedOrigin  = m_DraggedObject->DragStartLocation();
+        auto alignPivot     = ImVec2(0, 0);
+
+        // TODO: Move this experimental alignment to closes pivot out of internals to node API
+        if (auto draggedNode = m_DraggedObject->AsNode())
+        {
+            float x = FLT_MAX;
+            float y = FLT_MAX;
+
+            auto testPivot = [this, &x, &y, &draggedOrigin, &dragOffset, &alignPivot](const ImVec2& pivot)
+            {
+                auto initial   = draggedOrigin + dragOffset + pivot;
+                auto candidate = Editor->AlignPointToGrid(initial) - draggedOrigin - pivot;
+
+                if (ImFabs(candidate.x) < ImFabs(ImMin(x, FLT_MAX)))
+                {
+                    x = candidate.x;
+                    alignPivot.x = pivot.x;
+                }
+
+                if (ImFabs(candidate.y) < ImFabs(ImMin(y, FLT_MAX)))
+                {
+                    y = candidate.y;
+                    alignPivot.y = pivot.y;
+                }
+            };
+
+            for (auto pin = draggedNode->m_LastPin; pin; pin = pin->m_PreviousPin)
+            {
+                auto pivot = pin->m_Pivot.GetCenter() - draggedNode->m_Bounds.Min;
+                testPivot(pivot);
+            }
+
+            //testPivot(point(0, 0));
+        }
+
+        auto alignedOffset  = Editor->AlignPointToGrid(draggedOrigin + dragOffset + alignPivot) - draggedOrigin - alignPivot;
+
+        if (!ImGui::GetIO().KeyAlt)
+            dragOffset = alignedOffset;
+
+        for (auto object : m_Objects)
+            object->UpdateDrag(dragOffset);
+    }
+    else if (!control.ActiveObject)
+    {
+        m_Clear = true;
+
+        m_IsActive = false;
+        return true;
+    }
+
+    return m_IsActive;
+}
+
+void ed::DragAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    auto getObjectName = [](Object* object)
+    {
+        if (!object) return "";
+        else if (object->AsNode())  return "Node";
+        else if (object->AsPin())   return "Pin";
+        else if (object->AsLink())  return "Link";
+        else return "";
+    };
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Active: %s", m_IsActive ? "yes" : "no");
+    ImGui::Text("    Node: %s (%p)", getObjectName(m_DraggedObject), m_DraggedObject ? m_DraggedObject->ID().AsPointer() : nullptr);
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Select Action
+//
+//------------------------------------------------------------------------------
+ed::SelectAction::SelectAction(EditorContext* editor):
+    EditorAction(editor),
+    m_IsActive(false),
+    m_SelectGroups(false),
+    m_SelectLinkMode(false),
+    m_CommitSelection(false),
+    m_StartPoint(),
+    m_Animation(editor)
+{
+}
+
+ed::EditorAction::AcceptResult ed::SelectAction::Accept(const Control& control)
+{
+    IM_ASSERT(!m_IsActive);
+
+    if (m_IsActive)
+        return False;
+
+    auto& io = ImGui::GetIO();
+    m_SelectGroups   = io.KeyShift;
+    m_SelectLinkMode = io.KeyAlt;
+
+    m_SelectedObjectsAtStart.clear();
+
+    if (control.BackgroundActive && ImGui::IsMouseDragging(0, 1))
+    {
+        m_IsActive = true;
+        m_StartPoint = ImGui::GetMousePos();
+        m_EndPoint   = m_StartPoint;
+
+        // Links and nodes cannot be selected together
+        if ((m_SelectLinkMode && Editor->IsAnyNodeSelected()) ||
+           (!m_SelectLinkMode && Editor->IsAnyLinkSelected()))
+        {
+            Editor->ClearSelection();
+        }
+
+        if (io.KeyCtrl)
+            m_SelectedObjectsAtStart = Editor->GetSelectedObjects();
+    }
+    else if (control.BackgroundClicked)
+    {
+        Editor->ClearSelection();
+    }
+    else
+    {
+        Object* clickedObject = control.ClickedNode ? static_cast<Object*>(control.ClickedNode) : static_cast<Object*>(control.ClickedLink);
+
+        if (clickedObject)
+        {
+            // Links and nodes cannot be selected together
+            if ((clickedObject->AsLink() && Editor->IsAnyNodeSelected()) ||
+                (clickedObject->AsNode() && Editor->IsAnyLinkSelected()))
+            {
+                Editor->ClearSelection();
+            }
+
+            if (io.KeyCtrl)
+                Editor->ToggleObjectSelection(clickedObject);
+            else
+                Editor->SetSelectedObject(clickedObject);
+        }
+    }
+
+    if (m_IsActive)
+        m_Animation.Stop();
+
+    return m_IsActive ? True : False;
+}
+
+bool ed::SelectAction::Process(const Control& control)
+{
+    IM_UNUSED(control);
+
+    if (m_CommitSelection)
+    {
+        Editor->ClearSelection();
+        for (auto object : m_CandidateObjects)
+            Editor->SelectObject(object);
+
+        m_CandidateObjects.clear();
+
+        m_CommitSelection = false;
+    }
+
+    if (!m_IsActive)
+        return false;
+
+    if (ImGui::IsMouseDragging(0, 0))
+    {
+        m_EndPoint = ImGui::GetMousePos();
+
+        auto topLeft     = ImVec2(std::min(m_StartPoint.x, m_EndPoint.x), std::min(m_StartPoint.y, m_EndPoint.y));
+        auto bottomRight = ImVec2(ImMax(m_StartPoint.x, m_EndPoint.x), ImMax(m_StartPoint.y, m_EndPoint.y));
+        auto rect        = ImRect(topLeft, bottomRight);
+        if (rect.GetWidth() <= 0)
+            rect.Max.x = rect.Min.x + 1;
+        if (rect.GetHeight() <= 0)
+            rect.Max.y = rect.Min.y + 1;
+
+        vector<Node*> nodes;
+        vector<Link*> links;
+
+        if (m_SelectLinkMode)
+        {
+            Editor->FindLinksInRect(rect, links);
+            m_CandidateObjects.assign(links.begin(), links.end());
+        }
+        else
+        {
+            Editor->FindNodesInRect(rect, nodes);
+            m_CandidateObjects.assign(nodes.begin(), nodes.end());
+
+            if (m_SelectGroups)
+            {
+                auto endIt = std::remove_if(m_CandidateObjects.begin(), m_CandidateObjects.end(), [](Object* object) { return !IsGroup(object->AsNode()); });
+                m_CandidateObjects.erase(endIt, m_CandidateObjects.end());
+            }
+            else
+            {
+                auto endIt = std::remove_if(m_CandidateObjects.begin(), m_CandidateObjects.end(), [](Object* object) { return IsGroup(object->AsNode()); });
+                m_CandidateObjects.erase(endIt, m_CandidateObjects.end());
+            }
+        }
+
+        m_CandidateObjects.insert(m_CandidateObjects.end(), m_SelectedObjectsAtStart.begin(), m_SelectedObjectsAtStart.end());
+        std::sort(m_CandidateObjects.begin(), m_CandidateObjects.end());
+        m_CandidateObjects.erase(std::unique(m_CandidateObjects.begin(), m_CandidateObjects.end()), m_CandidateObjects.end());
+    }
+    else
+    {
+        m_IsActive = false;
+
+        m_Animation.Play(c_SelectionFadeOutDuration);
+
+        m_CommitSelection = true;
+
+        return true;
+    }
+
+    return m_IsActive;
+}
+
+void ed::SelectAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Active: %s", m_IsActive ? "yes" : "no");
+}
+
+void ed::SelectAction::Draw(ImDrawList* drawList)
+{
+    if (!m_IsActive && !m_Animation.IsPlaying())
+        return;
+
+    const auto alpha = m_Animation.IsPlaying() ? ImEasing::EaseOutQuad(1.0f, -1.0f, m_Animation.GetProgress()) : 1.0f;
+
+    const auto fillColor    = Editor->GetColor(m_SelectLinkMode ? StyleColor_LinkSelRect       : StyleColor_NodeSelRect, alpha);
+    const auto outlineColor = Editor->GetColor(m_SelectLinkMode ? StyleColor_LinkSelRectBorder : StyleColor_NodeSelRectBorder, alpha);
+
+    drawList->ChannelsSetCurrent(c_BackgroundChannel_SelectionRect);
+
+    auto min  = ImVec2(std::min(m_StartPoint.x, m_EndPoint.x), std::min(m_StartPoint.y, m_EndPoint.y));
+    auto max  = ImVec2(ImMax(m_StartPoint.x, m_EndPoint.x), ImMax(m_StartPoint.y, m_EndPoint.y));
+
+    drawList->AddRectFilled(min, max, fillColor);
+    FringeScaleScope fringe(1.0f);
+    drawList->AddRect(min, max, outlineColor);
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Context Menu Action
+//
+//------------------------------------------------------------------------------
+ed::ContextMenuAction::ContextMenuAction(EditorContext* editor):
+    EditorAction(editor),
+    m_CandidateMenu(Menu::None),
+    m_CurrentMenu(Menu::None),
+    m_ContextId()
+{
+}
+
+ed::EditorAction::AcceptResult ed::ContextMenuAction::Accept(const Control& control)
+{
+    const auto isPressed  = ImGui::IsMouseClicked(1);
+    const auto isReleased = ImGui::IsMouseReleased(1);
+    const auto isDragging = ImGui::IsMouseDragging(1);
+
+    if (isPressed || isReleased || isDragging)
+    {
+        Menu candidateMenu = ContextMenuAction::None;
+        ObjectId contextId;
+
+        if (auto hotObejct = control.HotObject)
+        {
+            if (hotObejct->AsNode())
+                candidateMenu = Node;
+            else if (hotObejct->AsPin())
+                candidateMenu = Pin;
+            else if (hotObejct->AsLink())
+                candidateMenu = Link;
+
+            if (candidateMenu != None)
+                contextId = hotObejct->ID();
+        }
+        else if (control.BackgroundHot)
+            candidateMenu = Background;
+
+        if (isPressed)
+        {
+            m_CandidateMenu = candidateMenu;
+            m_ContextId     = contextId;
+            return Possible;
+        }
+        else if (isReleased && m_CandidateMenu == candidateMenu && m_ContextId == contextId)
+        {
+            m_CurrentMenu   = m_CandidateMenu;
+            m_CandidateMenu = ContextMenuAction::None;
+            return True;
+        }
+        else
+        {
+            m_CandidateMenu = None;
+            m_CurrentMenu   = None;
+            m_ContextId     = ObjectId();
+            return False;
+        }
+    }
+
+    return False;
+}
+
+bool ed::ContextMenuAction::Process(const Control& control)
+{
+    IM_UNUSED(control);
+
+    m_CandidateMenu = None;
+    m_CurrentMenu   = None;
+    m_ContextId     = ObjectId();
+    return false;
+}
+
+void ed::ContextMenuAction::Reject()
+{
+    m_CandidateMenu = None;
+    m_CurrentMenu   = None;
+    m_ContextId     = ObjectId();
+}
+
+void ed::ContextMenuAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    auto getMenuName = [](Menu menu)
+    {
+        switch (menu)
+        {
+            default:
+            case None:        return "None";
+            case Node:        return "Node";
+            case Pin:         return "Pin";
+            case Link:        return "Link";
+            case Background:  return "Background";
+        }
+    };
+
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Menu: %s", getMenuName(m_CurrentMenu));
+}
+
+bool ed::ContextMenuAction::ShowNodeContextMenu(NodeId* nodeId)
+{
+    if (m_CurrentMenu != Node)
+        return false;
+
+    *nodeId = m_ContextId.AsNodeId();
+    Editor->SetUserContext();
+    return true;
+}
+
+bool ed::ContextMenuAction::ShowPinContextMenu(PinId* pinId)
+{
+    if (m_CurrentMenu != Pin)
+        return false;
+
+    *pinId = m_ContextId.AsPinId();
+    Editor->SetUserContext();
+    return true;
+}
+
+bool ed::ContextMenuAction::ShowLinkContextMenu(LinkId* linkId)
+{
+    if (m_CurrentMenu != Link)
+        return false;
+
+    *linkId = m_ContextId.AsLinkId();
+    Editor->SetUserContext();
+    return true;
+}
+
+bool ed::ContextMenuAction::ShowBackgroundContextMenu()
+{
+    if (m_CurrentMenu != Background)
+        return false;
+
+    Editor->SetUserContext();
+    return true;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Cut/Copy/Paste Action
+//
+//------------------------------------------------------------------------------
+ed::ShortcutAction::ShortcutAction(EditorContext* editor):
+    EditorAction(editor),
+    m_IsActive(false),
+    m_InAction(false),
+    m_CurrentAction(Action::None),
+    m_Context()
+{
+}
+
+ed::EditorAction::AcceptResult ed::ShortcutAction::Accept(const Control& control)
+{
+    if (!Editor->IsActive() || !Editor->AreShortcutsEnabled())
+        return False;
+
+    Action candidateAction = None;
+
+    auto& io = ImGui::GetIO();
+    if (io.KeyCtrl && !io.KeyShift && !io.KeyAlt && ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_X)))
+        candidateAction = Cut;
+    if (io.KeyCtrl && !io.KeyShift && !io.KeyAlt && ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_C)))
+        candidateAction = Copy;
+    if (io.KeyCtrl && !io.KeyShift && !io.KeyAlt && ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_V)))
+        candidateAction = Paste;
+    if (io.KeyCtrl && !io.KeyShift && !io.KeyAlt && ImGui::IsKeyPressed(GetKeyIndexForD()))
+        candidateAction = Duplicate;
+    if (!io.KeyCtrl && !io.KeyShift && !io.KeyAlt && ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_Space)))
+        candidateAction = CreateNode;
+
+    if (candidateAction != None)
+    {
+        if (candidateAction != Paste && candidateAction != CreateNode)
+        {
+            auto& selection = Editor->GetSelectedObjects();
+            if (!selection.empty())
+            {
+                // #TODO: Find a way to simplify logic.
+
+                m_Context.assign(selection.begin(), selection.end());
+
+                // Expand groups
+                vector<Node*> extra;
+                for (auto object : m_Context)
+                {
+                    auto node = object->AsNode();
+                    if (IsGroup(node))
+                        node->GetGroupedNodes(extra, true);
+                }
+
+                // Apply groups and remove duplicates
+                if (!extra.empty())
+                {
+                    m_Context.insert(m_Context.end(), extra.begin(), extra.end());
+                    std::sort(m_Context.begin(), m_Context.end());
+                    m_Context.erase(std::unique(m_Context.begin(), m_Context.end()), m_Context.end());
+                }
+            }
+            else if (control.HotObject && control.HotObject->IsSelectable() && !IsGroup(control.HotObject->AsNode()))
+            {
+                m_Context.push_back(control.HotObject);
+            }
+
+            if (m_Context.empty())
+                return False;
+
+            // Does copying only links make sense?
+            //const auto hasOnlyLinks = std::all_of(Context.begin(), Context.end(), [](Object* object) { return object->AsLink() != nullptr; });
+            //if (hasOnlyLinks)
+            //    return False;
+
+            // If no links are selected, pick all links between nodes within context
+            const auto hasAnyLinks = std::any_of(m_Context.begin(), m_Context.end(), [](Object* object) { return object->AsLink() != nullptr; });
+            if (!hasAnyLinks && m_Context.size() > 1) // one node cannot make connection to anything
+            {
+                // Collect nodes in sorted vector viable for binary search
+                std::vector<ObjectWrapper<Node>> nodes;
+
+                nodes.reserve(m_Context.size());
+                std::for_each(m_Context.begin(), m_Context.end(), [&nodes](Object* object) { if (auto node = object->AsNode()) nodes.push_back({node->m_ID, node}); });
+
+                std::sort(nodes.begin(), nodes.end());
+
+                auto isNodeInContext = [&nodes](NodeId nodeId)
+                {
+                    return std::binary_search(nodes.begin(), nodes.end(), ObjectWrapper<Node>{nodeId, nullptr});
+                };
+
+                // Collect links connected to nodes and drop those reaching out of context
+                std::vector<Link*> links;
+
+                for (auto node : nodes)
+                    Editor->FindLinksForNode(node.m_ID, links, true);
+
+                // Remove duplicates
+                std::sort(links.begin(), links.end());
+                links.erase(std::unique(links.begin(), links.end()), links.end());
+
+                // Drop out of context links
+                links.erase(std::remove_if(links.begin(), links.end(), [&isNodeInContext](Link* link)
+                {
+                    return !isNodeInContext(link->m_StartPin->m_Node->m_ID) || !isNodeInContext(link->m_EndPin->m_Node->m_ID);
+                }), links.end());
+
+                // Append links and remove duplicates
+                m_Context.insert(m_Context.end(), links.begin(), links.end());
+            }
+        }
+        else
+            m_Context.resize(0);
+
+        m_IsActive      = true;
+        m_CurrentAction = candidateAction;
+
+        return True;
+    }
+
+    return False;
+}
+
+bool ed::ShortcutAction::Process(const Control& control)
+{
+    IM_UNUSED(control);
+
+    m_IsActive        = false;
+    m_CurrentAction   = None;
+    m_Context.resize(0);
+    return false;
+}
+
+void ed::ShortcutAction::Reject()
+{
+    m_IsActive        = false;
+    m_CurrentAction   = None;
+    m_Context.resize(0);
+}
+
+void ed::ShortcutAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    auto getActionName = [](Action action)
+    {
+        switch (action)
+        {
+            default:
+            case None:       return "None";
+            case Cut:        return "Cut";
+            case Copy:       return "Copy";
+            case Paste:      return "Paste";
+            case Duplicate:  return "Duplicate";
+            case CreateNode: return "CreateNode";
+        }
+    };
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Action: %s", getActionName(m_CurrentAction));
+}
+
+bool ed::ShortcutAction::Begin()
+{
+    if (m_IsActive)
+        m_InAction = true;
+    return m_IsActive;
+}
+
+void ed::ShortcutAction::End()
+{
+    if (m_IsActive)
+        m_InAction = false;
+}
+
+bool ed::ShortcutAction::AcceptCut()
+{
+    IM_ASSERT(m_InAction);
+    return m_CurrentAction == Cut;
+}
+
+bool ed::ShortcutAction::AcceptCopy()
+{
+    IM_ASSERT(m_InAction);
+    return m_CurrentAction == Copy;
+}
+
+bool ed::ShortcutAction::AcceptPaste()
+{
+    IM_ASSERT(m_InAction);
+    return m_CurrentAction == Paste;
+}
+
+bool ed::ShortcutAction::AcceptDuplicate()
+{
+    IM_ASSERT(m_InAction);
+    return m_CurrentAction == Duplicate;
+}
+
+bool ed::ShortcutAction::AcceptCreateNode()
+{
+    IM_ASSERT(m_InAction);
+    return m_CurrentAction == CreateNode;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Create Item Action
+//
+//------------------------------------------------------------------------------
+ed::CreateItemAction::CreateItemAction(EditorContext* editor):
+    EditorAction(editor),
+    m_InActive(false),
+    m_NextStage(None),
+    m_CurrentStage(None),
+    m_ItemType(NoItem),
+    m_UserAction(Unknown),
+    m_LinkColor(IM_COL32_WHITE),
+    m_LinkThickness(1.0f),
+    m_LinkStart(nullptr),
+    m_LinkEnd(nullptr),
+
+    m_IsActive(false),
+    m_DraggedPin(nullptr),
+
+    m_IsInGlobalSpace(false)
+{
+}
+
+ed::EditorAction::AcceptResult ed::CreateItemAction::Accept(const Control& control)
+{
+    IM_ASSERT(!m_IsActive);
+
+    if (m_IsActive)
+        return EditorAction::False;
+
+    if (control.ActivePin && ImGui::IsMouseDragging(0))
+    {
+        m_DraggedPin = control.ActivePin;
+        DragStart(m_DraggedPin);
+
+        Editor->ClearSelection();
+    }
+    else if (control.HotPin)
+    {
+        return EditorAction::Possible;
+    }
+    else
+        return EditorAction::False;
+
+    m_IsActive = true;
+
+    return EditorAction::True;
+}
+
+bool ed::CreateItemAction::Process(const Control& control)
+{
+    IM_ASSERT(m_IsActive);
+
+    if (!m_IsActive)
+        return false;
+
+    if (m_DraggedPin && control.ActivePin == m_DraggedPin && (m_CurrentStage == Possible))
+    {
+        const auto draggingFromSource = (m_DraggedPin->m_Kind == PinKind::Output);
+
+        ed::Pin cursorPin(Editor, 0, draggingFromSource ? PinKind::Input : PinKind::Output);
+        cursorPin.m_Pivot    = ImRect(ImGui::GetMousePos(), ImGui::GetMousePos());
+        cursorPin.m_Dir      = -m_DraggedPin->m_Dir;
+        cursorPin.m_Strength =  m_DraggedPin->m_Strength;
+
+        ed::Link candidate(Editor, 0);
+        candidate.m_Color    = m_LinkColor;
+        candidate.m_StartPin = draggingFromSource ? m_DraggedPin : &cursorPin;
+        candidate.m_EndPin   = draggingFromSource ? &cursorPin : m_DraggedPin;
+
+        ed::Pin*& freePin  = draggingFromSource ? candidate.m_EndPin : candidate.m_StartPin;
+
+        if (control.HotPin)
+        {
+            DropPin(control.HotPin);
+
+            if (m_UserAction == UserAccept)
+                freePin = control.HotPin;
+        }
+        else if (control.BackgroundHot)
+            DropNode();
+        else
+            DropNothing();
+
+        auto drawList = ImGui::GetWindowDrawList();
+        drawList->ChannelsSetCurrent(c_LinkChannel_NewLink);
+
+        candidate.UpdateEndpoints();
+        candidate.Draw(drawList, m_LinkColor, m_LinkThickness);
+    }
+    else if (m_CurrentStage == Possible || !control.ActivePin)
+    {
+        if (!ImGui::IsWindowHovered())
+        {
+            m_DraggedPin = nullptr;
+            DropNothing();
+        }
+
+        DragEnd();
+        m_IsActive = false;
+    }
+
+    return m_IsActive;
+}
+
+void ed::CreateItemAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    auto getStageName = [](Stage stage)
+    {
+        switch (stage)
+        {
+            case None:     return "None";
+            case Possible: return "Possible";
+            case Create:   return "Create";
+            default:       return "<unknown>";
+        }
+    };
+
+    auto getActionName = [](Action action)
+    {
+        switch (action)
+        {
+            default:
+            case Unknown:     return "Unknown";
+            case UserReject:  return "Reject";
+            case UserAccept:  return "Accept";
+        }
+    };
+
+    auto getItemName = [](Type item)
+    {
+        switch (item)
+        {
+            default:
+            case NoItem: return "None";
+            case Node:   return "Node";
+            case Link:   return "Link";
+        }
+    };
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Stage: %s", getStageName(m_CurrentStage));
+    ImGui::Text("    User Action: %s", getActionName(m_UserAction));
+    ImGui::Text("    Item Type: %s", getItemName(m_ItemType));
+}
+
+void ed::CreateItemAction::SetStyle(ImU32 color, float thickness)
+{
+    m_LinkColor     = color;
+    m_LinkThickness = thickness;
+}
+
+bool ed::CreateItemAction::Begin()
+{
+    IM_ASSERT(false == m_InActive);
+
+    m_InActive        = true;
+    m_CurrentStage    = m_NextStage;
+    m_UserAction      = Unknown;
+    m_LinkColor       = IM_COL32_WHITE;
+    m_LinkThickness   = 1.0f;
+
+    if (m_CurrentStage == None)
+        return false;
+
+    m_LastChannel = ImGui::GetWindowDrawList()->_Splitter._Current;
+
+    return true;
+}
+
+void ed::CreateItemAction::End()
+{
+    IM_ASSERT(m_InActive);
+
+    if (m_IsInGlobalSpace)
+    {
+        ImGui::PopClipRect();
+        Editor->Resume(SuspendFlags::KeepSplitter);
+
+        auto currentChannel = ImGui::GetWindowDrawList()->_Splitter._Current;
+        if (currentChannel != m_LastChannel)
+            ImGui::GetWindowDrawList()->ChannelsSetCurrent(m_LastChannel);
+
+        m_IsInGlobalSpace = false;
+    }
+
+    m_InActive = false;
+}
+
+void ed::CreateItemAction::DragStart(Pin* startPin)
+{
+    IM_ASSERT(!m_InActive);
+
+    m_NextStage = Possible;
+    m_LinkStart = startPin;
+    m_LinkEnd   = nullptr;
+}
+
+void ed::CreateItemAction::DragEnd()
+{
+    IM_ASSERT(!m_InActive);
+
+    if (m_CurrentStage == Possible && m_UserAction == UserAccept)
+    {
+        m_NextStage = Create;
+    }
+    else
+    {
+        m_NextStage = None;
+        m_ItemType  = NoItem;
+        m_LinkStart = nullptr;
+        m_LinkEnd   = nullptr;
+    }
+}
+
+void ed::CreateItemAction::DropPin(Pin* endPin)
+{
+    IM_ASSERT(!m_InActive);
+
+    m_ItemType = Link;
+    m_LinkEnd  = endPin;
+}
+
+void ed::CreateItemAction::DropNode()
+{
+    IM_ASSERT(!m_InActive);
+
+    m_ItemType = Node;
+    m_LinkEnd  = nullptr;
+}
+
+void ed::CreateItemAction::DropNothing()
+{
+    IM_ASSERT(!m_InActive);
+
+    m_ItemType = NoItem;
+    m_LinkEnd  = nullptr;
+}
+
+ed::CreateItemAction::Result ed::CreateItemAction::RejectItem()
+{
+    IM_ASSERT(m_InActive);
+
+    if (!m_InActive || m_CurrentStage == None || m_ItemType == NoItem)
+        return Indeterminate;
+
+    m_UserAction = UserReject;
+
+    return True;
+}
+
+ed::CreateItemAction::Result ed::CreateItemAction::AcceptItem()
+{
+    IM_ASSERT(m_InActive);
+
+    if (!m_InActive || m_CurrentStage == None || m_ItemType == NoItem)
+        return Indeterminate;
+
+    m_UserAction = UserAccept;
+
+    if (m_CurrentStage == Create)
+    {
+        m_NextStage = None;
+        m_ItemType  = NoItem;
+        m_LinkStart = nullptr;
+        m_LinkEnd   = nullptr;
+        return True;
+    }
+    else
+        return False;
+}
+
+ed::CreateItemAction::Result ed::CreateItemAction::QueryLink(PinId* startId, PinId* endId)
+{
+    IM_ASSERT(m_InActive);
+
+    if (!m_InActive || m_CurrentStage == None || m_ItemType != Link)
+        return Indeterminate;
+
+    auto linkStartId = m_LinkStart->m_ID;
+    auto linkEndId   = m_LinkEnd->m_ID;
+
+    *startId = linkStartId;
+    *endId   = linkEndId;
+
+    Editor->SetUserContext(true);
+
+    if (!m_IsInGlobalSpace)
+    {
+        Editor->Suspend(SuspendFlags::KeepSplitter);
+
+        auto rect = Editor->GetRect();
+        ImGui::PushClipRect(rect.Min + ImVec2(1, 1), rect.Max - ImVec2(1, 1), false);
+        m_IsInGlobalSpace = true;
+    }
+
+    return True;
+}
+
+ed::CreateItemAction::Result ed::CreateItemAction::QueryNode(PinId* pinId)
+{
+    IM_ASSERT(m_InActive);
+
+    if (!m_InActive || m_CurrentStage == None || m_ItemType != Node)
+        return Indeterminate;
+
+    *pinId = m_LinkStart ? m_LinkStart->m_ID : 0;
+
+    Editor->SetUserContext(true);
+
+    if (!m_IsInGlobalSpace)
+    {
+        Editor->Suspend(SuspendFlags::KeepSplitter);
+
+        auto rect = Editor->GetRect();
+        ImGui::PushClipRect(rect.Min + ImVec2(1, 1), rect.Max - ImVec2(1, 1), false);
+        m_IsInGlobalSpace = true;
+    }
+
+    return True;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Delete Items Action
+//
+//------------------------------------------------------------------------------
+ed::DeleteItemsAction::DeleteItemsAction(EditorContext* editor):
+    EditorAction(editor),
+    m_IsActive(false),
+    m_InInteraction(false),
+    m_CurrentItemType(Unknown),
+    m_UserAction(Undetermined)
+{
+}
+
+ed::EditorAction::AcceptResult ed::DeleteItemsAction::Accept(const Control& control)
+{
+    IM_ASSERT(!m_IsActive);
+
+    if (m_IsActive)
+        return False;
+
+    auto addDeadLinks = [this]()
+    {
+        vector<ed::Link*> links;
+        for (auto object : m_CandidateObjects)
+        {
+            auto node = object->AsNode();
+            if (!node)
+                continue;
+
+            Editor->FindLinksForNode(node->m_ID, links, true);
+        }
+        if (!links.empty())
+        {
+            std::sort(links.begin(), links.end());
+            links.erase(std::unique(links.begin(), links.end()), links.end());
+            m_CandidateObjects.insert(m_CandidateObjects.end(), links.begin(), links.end());
+        }
+    };
+
+    auto& io = ImGui::GetIO();
+    if (ImGui::IsWindowFocused() && ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_Delete)) && Editor->AreShortcutsEnabled())
+    {
+        auto& selection = Editor->GetSelectedObjects();
+        if (!selection.empty())
+        {
+            m_CandidateObjects = selection;
+            addDeadLinks();
+            m_IsActive = true;
+            return True;
+        }
+    }
+    else if (control.ClickedLink && io.KeyAlt)
+    {
+        m_CandidateObjects.clear();
+        m_CandidateObjects.push_back(control.ClickedLink);
+        m_IsActive = true;
+        return True;
+    }
+
+    else if (!m_ManuallyDeletedObjects.empty())
+    {
+        m_CandidateObjects = m_ManuallyDeletedObjects;
+        m_ManuallyDeletedObjects.clear();
+        addDeadLinks();
+        m_IsActive = true;
+        return True;
+    }
+
+    return m_IsActive ? True : False;
+}
+
+bool ed::DeleteItemsAction::Process(const Control& control)
+{
+    IM_UNUSED(control);
+
+    if (!m_IsActive)
+        return false;
+
+    m_IsActive = false;
+    return true;
+}
+
+void ed::DeleteItemsAction::ShowMetrics()
+{
+    EditorAction::ShowMetrics();
+
+    //auto getObjectName = [](Object* object)
+    //{
+    //    if (!object) return "";
+    //    else if (object->AsNode()) return "Node";
+    //    else if (object->AsPin())  return "Pin";
+    //    else if (object->AsLink()) return "Link";
+    //    else return "";
+    //};
+
+    ImGui::Text("%s:", GetName());
+    ImGui::Text("    Active: %s", m_IsActive ? "yes" : "no");
+    //ImGui::Text("    Node: %s (%d)", getObjectName(DeleteItemsgedNode), DeleteItemsgedNode ? DeleteItemsgedNode->ID : 0);
+}
+
+bool ed::DeleteItemsAction::Add(Object* object)
+{
+    if (Editor->GetCurrentAction() != nullptr)
+        return false;
+
+    m_ManuallyDeletedObjects.push_back(object);
+
+    return true;
+}
+
+bool ed::DeleteItemsAction::Begin()
+{
+    if (!m_IsActive)
+        return false;
+
+    IM_ASSERT(!m_InInteraction);
+    m_InInteraction = true;
+
+    m_CurrentItemType = Unknown;
+    m_UserAction      = Undetermined;
+
+    return m_IsActive;
+}
+
+void ed::DeleteItemsAction::End()
+{
+    if (!m_IsActive)
+        return;
+
+    IM_ASSERT(m_InInteraction);
+    m_InInteraction = false;
+}
+
+bool ed::DeleteItemsAction::QueryLink(LinkId* linkId, PinId* startId, PinId* endId)
+{
+    ObjectId objectId;
+    if (!QueryItem(&objectId, Link))
+        return false;
+
+    if (auto id = objectId.AsLinkId())
+        *linkId = id;
+    else
+        return false;
+
+    if (startId || endId)
+    {
+        auto link = Editor->FindLink(*linkId);
+        if (startId)
+            *startId = link->m_StartPin->m_ID;
+        if (endId)
+            *endId = link->m_EndPin->m_ID;
+    }
+
+    return true;
+}
+
+bool ed::DeleteItemsAction::QueryNode(NodeId* nodeId)
+{
+    ObjectId objectId;
+    if (!QueryItem(&objectId, Node))
+        return false;
+
+    if (auto id = objectId.AsNodeId())
+        *nodeId = id;
+    else
+        return false;
+
+    return true;
+}
+
+bool ed::DeleteItemsAction::QueryItem(ObjectId* itemId, IteratorType itemType)
+{
+    if (!m_InInteraction)
+        return false;
+
+    if (m_CurrentItemType != itemType)
+    {
+        m_CurrentItemType    = itemType;
+        m_CandidateItemIndex = 0;
+    }
+    else if (m_UserAction == Undetermined)
+    {
+        RejectItem();
+    }
+
+    m_UserAction = Undetermined;
+
+    auto itemCount = (int)m_CandidateObjects.size();
+    while (m_CandidateItemIndex < itemCount)
+    {
+        auto item = m_CandidateObjects[m_CandidateItemIndex];
+        if (itemType == Node)
+        {
+            if (auto node = item->AsNode())
+            {
+                *itemId = node->m_ID;
+                return true;
+            }
+        }
+        else if (itemType == Link)
+        {
+            if (auto link = item->AsLink())
+            {
+                *itemId = link->m_ID;
+                return true;
+            }
+        }
+
+        ++m_CandidateItemIndex;
+    }
+
+    if (m_CandidateItemIndex == itemCount)
+        m_CurrentItemType = Unknown;
+
+    return false;
+}
+
+bool ed::DeleteItemsAction::AcceptItem()
+{
+    if (!m_InInteraction)
+        return false;
+
+    m_UserAction = Accepted;
+
+    RemoveItem();
+
+    return true;
+}
+
+void ed::DeleteItemsAction::RejectItem()
+{
+    if (!m_InInteraction)
+        return;
+
+    m_UserAction = Rejected;
+
+    RemoveItem();
+}
+
+void ed::DeleteItemsAction::RemoveItem()
+{
+    auto item = m_CandidateObjects[m_CandidateItemIndex];
+    m_CandidateObjects.erase(m_CandidateObjects.begin() + m_CandidateItemIndex);
+
+    Editor->DeselectObject(item);
+
+    if (m_CurrentItemType == Link)
+        Editor->NotifyLinkDeleted(item->AsLink());
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Node Builder
+//
+//------------------------------------------------------------------------------
+ed::NodeBuilder::NodeBuilder(EditorContext* editor):
+    Editor(editor),
+    m_CurrentNode(nullptr),
+    m_CurrentPin(nullptr)
+{
+}
+
+ed::NodeBuilder::~NodeBuilder()
+{
+    m_Splitter.ClearFreeMemory();
+    m_PinSplitter.ClearFreeMemory();
+}
+
+void ed::NodeBuilder::Begin(NodeId nodeId)
+{
+    IM_ASSERT(nullptr == m_CurrentNode);
+
+    m_CurrentNode = Editor->GetNode(nodeId);
+
+    if (m_CurrentNode->m_RestoreState)
+    {
+        Editor->RestoreNodeState(m_CurrentNode);
+        m_CurrentNode->m_RestoreState = false;
+    }
+
+    if (m_CurrentNode->m_CenterOnScreen)
+    {
+        auto bounds = Editor->GetViewRect();
+        auto offset = bounds.GetCenter() - m_CurrentNode->m_Bounds.GetCenter();
+
+        if (ImLengthSqr(offset) > 0)
+        {
+            if (::IsGroup(m_CurrentNode))
+            {
+                std::vector<Node*> groupedNodes;
+                m_CurrentNode->GetGroupedNodes(groupedNodes);
+                groupedNodes.push_back(m_CurrentNode);
+
+                for (auto node : groupedNodes)
+                {
+                    node->m_Bounds.Translate(ImFloor(offset));
+                    node->m_GroupBounds.Translate(ImFloor(offset));
+                    Editor->MakeDirty(SaveReasonFlags::Position | SaveReasonFlags::User, node);
+                }
+            }
+            else
+            {
+                m_CurrentNode->m_Bounds.Translate(ImFloor(offset));
+                m_CurrentNode->m_GroupBounds.Translate(ImFloor(offset));
+                Editor->MakeDirty(SaveReasonFlags::Position | SaveReasonFlags::User, m_CurrentNode);
+            }
+        }
+
+        m_CurrentNode->m_CenterOnScreen = false;
+    }
+
+    // Position node on screen
+    ImGui::SetCursorScreenPos(m_CurrentNode->m_Bounds.Min);
+
+    auto& editorStyle = Editor->GetStyle();
+
+    const auto alpha = ImGui::GetStyle().Alpha;
+
+    m_CurrentNode->m_IsLive           = true;
+    m_CurrentNode->m_LastPin          = nullptr;
+    m_CurrentNode->m_Color            = Editor->GetColor(StyleColor_NodeBg, alpha);
+    m_CurrentNode->m_BorderColor      = Editor->GetColor(StyleColor_NodeBorder, alpha);
+    m_CurrentNode->m_BorderWidth      = editorStyle.NodeBorderWidth;
+    m_CurrentNode->m_Rounding         = editorStyle.NodeRounding;
+    m_CurrentNode->m_GroupColor       = Editor->GetColor(StyleColor_GroupBg, alpha);
+    m_CurrentNode->m_GroupBorderColor = Editor->GetColor(StyleColor_GroupBorder, alpha);
+    m_CurrentNode->m_GroupBorderWidth = editorStyle.GroupBorderWidth;
+    m_CurrentNode->m_GroupRounding    = editorStyle.GroupRounding;
+
+    m_IsGroup = false;
+
+    // Grow channel list and select user channel
+    if (auto drawList = ImGui::GetWindowDrawList())
+    {
+        m_CurrentNode->m_Channel = drawList->_Splitter._Count;
+        ImDrawList_ChannelsGrow(drawList, drawList->_Splitter._Count + c_ChannelsPerNode);
+        drawList->ChannelsSetCurrent(m_CurrentNode->m_Channel + c_NodeContentChannel);
+
+        m_Splitter.Clear();
+        ImDrawList_SwapSplitter(drawList, m_Splitter);
+    }
+
+    // Begin outer group
+    ImGui::BeginGroup();
+
+    // Apply frame padding. Begin inner group if necessary.
+    if (editorStyle.NodePadding.x != 0 || editorStyle.NodePadding.y != 0 || editorStyle.NodePadding.z != 0 || editorStyle.NodePadding.w != 0)
+    {
+        ImGui::SetCursorPos(ImGui::GetCursorPos() + ImVec2(editorStyle.NodePadding.x, editorStyle.NodePadding.y));
+        ImGui::BeginGroup();
+    }
+}
+
+void ed::NodeBuilder::End()
+{
+    IM_ASSERT(nullptr != m_CurrentNode);
+
+    if (auto drawList = ImGui::GetWindowDrawList())
+    {
+        IM_ASSERT(drawList->_Splitter._Count == 1); // Did you forgot to call drawList->ChannelsMerge()?
+        ImDrawList_SwapSplitter(drawList, m_Splitter);
+    }
+
+    // Apply frame padding. This must be done in this convoluted way if outer group
+    // size must contain inner group padding.
+    auto& editorStyle = Editor->GetStyle();
+    if (editorStyle.NodePadding.x != 0 || editorStyle.NodePadding.y != 0 || editorStyle.NodePadding.z != 0 || editorStyle.NodePadding.w != 0)
+    {
+        ImGui::EndGroup();
+        ImGui::SameLine(0, editorStyle.NodePadding.z);
+        ImGui::Dummy(ImVec2(0, 0));
+        ImGui::SetCursorPosY(ImGui::GetCursorPosY() + editorStyle.NodePadding.w);
+    }
+
+    // End outer group.
+    ImGui::EndGroup();
+
+    m_NodeRect = ImGui_GetItemRect();
+    m_NodeRect.Floor();
+
+    if (m_CurrentNode->m_Bounds.GetSize() != m_NodeRect.GetSize())
+    {
+        m_CurrentNode->m_Bounds.Max = m_CurrentNode->m_Bounds.Min + m_NodeRect.GetSize();
+        Editor->MakeDirty(SaveReasonFlags::Size, m_CurrentNode);
+    }
+
+    if (m_IsGroup)
+    {
+        // Groups cannot have pins. Discard them.
+        for (auto pin = m_CurrentNode->m_LastPin; pin; pin = pin->m_PreviousPin)
+            pin->Reset();
+
+        m_CurrentNode->m_Type        = NodeType::Group;
+        m_CurrentNode->m_GroupBounds = m_GroupBounds;
+        m_CurrentNode->m_LastPin     = nullptr;
+    }
+    else
+        m_CurrentNode->m_Type        = NodeType::Node;
+
+    m_CurrentNode = nullptr;
+}
+
+void ed::NodeBuilder::BeginPin(PinId pinId, PinKind kind)
+{
+    IM_ASSERT(nullptr != m_CurrentNode);
+    IM_ASSERT(nullptr == m_CurrentPin);
+    IM_ASSERT(false   == m_IsGroup);
+
+    auto& editorStyle = Editor->GetStyle();
+
+    m_CurrentPin = Editor->GetPin(pinId, kind);
+    m_CurrentPin->m_Node = m_CurrentNode;
+
+    m_CurrentPin->m_IsLive      = true;
+    m_CurrentPin->m_Color       = Editor->GetColor(StyleColor_PinRect);
+    m_CurrentPin->m_BorderColor = Editor->GetColor(StyleColor_PinRectBorder);
+    m_CurrentPin->m_BorderWidth = editorStyle.PinBorderWidth;
+    m_CurrentPin->m_Rounding    = editorStyle.PinRounding;
+    m_CurrentPin->m_Corners     = static_cast<int>(editorStyle.PinCorners);
+    m_CurrentPin->m_Radius      = editorStyle.PinRadius;
+    m_CurrentPin->m_ArrowSize   = editorStyle.PinArrowSize;
+    m_CurrentPin->m_ArrowWidth  = editorStyle.PinArrowWidth;
+    m_CurrentPin->m_Dir         = kind == PinKind::Output ? editorStyle.SourceDirection : editorStyle.TargetDirection;
+    m_CurrentPin->m_Strength    = editorStyle.LinkStrength;
+
+    m_CurrentPin->m_PreviousPin = m_CurrentNode->m_LastPin;
+    m_CurrentNode->m_LastPin    = m_CurrentPin;
+
+    m_PivotAlignment          = editorStyle.PivotAlignment;
+    m_PivotSize               = editorStyle.PivotSize;
+    m_PivotScale              = editorStyle.PivotScale;
+    m_ResolvePinRect          = true;
+    m_ResolvePivot            = true;
+
+    if (auto drawList = ImGui::GetWindowDrawList())
+    {
+        m_PinSplitter.Clear();
+        ImDrawList_SwapSplitter(drawList, m_PinSplitter);
+    }
+
+    ImGui::BeginGroup();
+}
+
+void ed::NodeBuilder::EndPin()
+{
+    IM_ASSERT(nullptr != m_CurrentPin);
+
+    if (auto drawList = ImGui::GetWindowDrawList())
+    {
+        IM_ASSERT(drawList->_Splitter._Count == 1); // Did you forgot to call drawList->ChannelsMerge()?
+        ImDrawList_SwapSplitter(drawList, m_PinSplitter);
+    }
+
+    ImGui::EndGroup();
+
+    if (m_ResolvePinRect)
+        m_CurrentPin->m_Bounds = ImGui_GetItemRect();
+
+    if (m_ResolvePivot)
+    {
+        auto& pinRect = m_CurrentPin->m_Bounds;
+
+        if (m_PivotSize.x < 0)
+            m_PivotSize.x = pinRect.GetWidth();
+        if (m_PivotSize.y < 0)
+            m_PivotSize.y = pinRect.GetHeight();
+
+        m_CurrentPin->m_Pivot.Min = pinRect.Min + ImMul(pinRect.GetSize(), m_PivotAlignment);
+        m_CurrentPin->m_Pivot.Max = m_CurrentPin->m_Pivot.Min + ImMul(m_PivotSize, m_PivotScale);
+    }
+
+    // #debug: Draw pin bounds
+    //ImGui::GetWindowDrawList()->AddRect(m_CurrentPin->m_Bounds.Min, m_CurrentPin->m_Bounds.Max, IM_COL32(255, 255, 0, 255));
+
+    // #debug: Draw pin pivot rectangle
+    //ImGui::GetWindowDrawList()->AddRect(m_CurrentPin->m_Pivot.Min, m_CurrentPin->m_Pivot.Max, IM_COL32(255, 0, 255, 255));
+
+    m_CurrentPin = nullptr;
+}
+
+void ed::NodeBuilder::PinRect(const ImVec2& a, const ImVec2& b)
+{
+    IM_ASSERT(nullptr != m_CurrentPin);
+
+    m_CurrentPin->m_Bounds = ImRect(a, b);
+    m_CurrentPin->m_Bounds.Floor();
+    m_ResolvePinRect     = false;
+}
+
+void ed::NodeBuilder::PinPivotRect(const ImVec2& a, const ImVec2& b)
+{
+    IM_ASSERT(nullptr != m_CurrentPin);
+
+    m_CurrentPin->m_Pivot = ImRect(a, b);
+    m_ResolvePivot      = false;
+}
+
+void ed::NodeBuilder::PinPivotSize(const ImVec2& size)
+{
+    IM_ASSERT(nullptr != m_CurrentPin);
+
+    m_PivotSize    = size;
+    m_ResolvePivot = true;
+}
+
+void ed::NodeBuilder::PinPivotScale(const ImVec2& scale)
+{
+    IM_ASSERT(nullptr != m_CurrentPin);
+
+    m_PivotScale   = scale;
+    m_ResolvePivot = true;
+}
+
+void ed::NodeBuilder::PinPivotAlignment(const ImVec2& alignment)
+{
+    IM_ASSERT(nullptr != m_CurrentPin);
+
+    m_PivotAlignment = alignment;
+    m_ResolvePivot   = true;
+}
+
+void ed::NodeBuilder::Group(const ImVec2& size)
+{
+    IM_ASSERT(nullptr != m_CurrentNode);
+    IM_ASSERT(nullptr == m_CurrentPin);
+    IM_ASSERT(false   == m_IsGroup);
+
+    m_IsGroup = true;
+
+    if (IsGroup(m_CurrentNode))
+        ImGui::Dummy(m_CurrentNode->m_GroupBounds.GetSize());
+    else
+        ImGui::Dummy(size);
+
+    m_GroupBounds = ImGui_GetItemRect();
+    m_GroupBounds.Floor();
+}
+
+ImDrawList* ed::NodeBuilder::GetUserBackgroundDrawList() const
+{
+    return GetUserBackgroundDrawList(m_CurrentNode);
+}
+
+ImDrawList* ed::NodeBuilder::GetUserBackgroundDrawList(Node* node) const
+{
+    if (node && node->m_IsLive)
+    {
+        auto drawList = ImGui::GetWindowDrawList();
+        drawList->ChannelsSetCurrent(node->m_Channel + c_NodeUserBackgroundChannel);
+        return drawList;
+    }
+    else
+        return nullptr;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Node Builder
+//
+//------------------------------------------------------------------------------
+ed::HintBuilder::HintBuilder(EditorContext* editor):
+    Editor(editor),
+    m_IsActive(false),
+    m_CurrentNode(nullptr)
+{
+}
+
+bool ed::HintBuilder::Begin(NodeId nodeId)
+{
+    IM_ASSERT(nullptr == m_CurrentNode);
+
+    auto& view = Editor->GetView();
+    auto& rect = Editor->GetRect();
+
+    const float c_min_zoom = 0.75f;
+    const float c_max_zoom = 0.50f;
+
+    if (view.Scale > 0.75f)
+        return false;
+
+    auto node = Editor->FindNode(nodeId);
+    if (!IsGroup(node))
+        return false;
+
+    m_CurrentNode = node;
+
+    m_LastChannel = ImGui::GetWindowDrawList()->_Splitter._Current;
+
+    Editor->Suspend(SuspendFlags::KeepSplitter);
+
+    const auto alpha = ImMax(0.0f, std::min(1.0f, (view.Scale - c_min_zoom) / (c_max_zoom - c_min_zoom)));
+
+    ImGui::GetWindowDrawList()->ChannelsSetCurrent(c_UserChannel_HintsBackground);
+    ImGui::PushClipRect(rect.Min + ImVec2(1, 1), rect.Max - ImVec2(1, 1), false);
+
+    ImGui::GetWindowDrawList()->ChannelsSetCurrent(c_UserChannel_Hints);
+    ImGui::PushClipRect(rect.Min + ImVec2(1, 1), rect.Max - ImVec2(1, 1), false);
+
+    ImGui::PushStyleVar(ImGuiStyleVar_Alpha, alpha);
+
+    m_IsActive = true;
+
+    return true;
+}
+
+void ed::HintBuilder::End()
+{
+    if (!m_IsActive)
+        return;
+
+    ImGui::PopStyleVar();
+
+    ImGui::GetWindowDrawList()->ChannelsSetCurrent(c_UserChannel_Hints);
+    ImGui::PopClipRect();
+
+    ImGui::GetWindowDrawList()->ChannelsSetCurrent(c_UserChannel_HintsBackground);
+    ImGui::PopClipRect();
+
+    ImGui::GetWindowDrawList()->ChannelsSetCurrent(m_LastChannel);
+
+    Editor->Resume(SuspendFlags::KeepSplitter);
+
+    m_IsActive    = false;
+    m_CurrentNode = nullptr;
+}
+
+ImVec2 ed::HintBuilder::GetGroupMin()
+{
+    IM_ASSERT(nullptr != m_CurrentNode);
+
+    return Editor->ToScreen(m_CurrentNode->m_Bounds.Min);
+}
+
+ImVec2 ed::HintBuilder::GetGroupMax()
+{
+    IM_ASSERT(nullptr != m_CurrentNode);
+
+    return Editor->ToScreen(m_CurrentNode->m_Bounds.Max);
+}
+
+ImDrawList* ed::HintBuilder::GetForegroundDrawList()
+{
+    IM_ASSERT(nullptr != m_CurrentNode);
+
+    auto drawList = ImGui::GetWindowDrawList();
+
+    drawList->ChannelsSetCurrent(c_UserChannel_Hints);
+
+    return drawList;
+}
+
+ImDrawList* ed::HintBuilder::GetBackgroundDrawList()
+{
+    IM_ASSERT(nullptr != m_CurrentNode);
+
+    auto drawList = ImGui::GetWindowDrawList();
+
+    drawList->ChannelsSetCurrent(c_UserChannel_HintsBackground);
+
+    return drawList;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Style
+//
+//------------------------------------------------------------------------------
+void ed::Style::PushColor(StyleColor colorIndex, const ImVec4& color)
+{
+    ColorModifier modifier;
+    modifier.Index = colorIndex;
+    modifier.Value = Colors[colorIndex];
+    m_ColorStack.push_back(modifier);
+    Colors[colorIndex] = color;
+}
+
+void ed::Style::PopColor(int count)
+{
+    while (count > 0)
+    {
+        auto& modifier = m_ColorStack.back();
+        Colors[modifier.Index] = modifier.Value;
+        m_ColorStack.pop_back();
+        --count;
+    }
+}
+
+void ed::Style::PushVar(StyleVar varIndex, float value)
+{
+    auto* var = GetVarFloatAddr(varIndex);
+    IM_ASSERT(var != nullptr);
+    VarModifier modifier;
+    modifier.Index = varIndex;
+    modifier.Value = ImVec4(*var, 0, 0, 0);
+    *var = value;
+    m_VarStack.push_back(modifier);
+}
+
+void ed::Style::PushVar(StyleVar varIndex, const ImVec2& value)
+{
+    auto* var = GetVarVec2Addr(varIndex);
+    IM_ASSERT(var != nullptr);
+    VarModifier modifier;
+    modifier.Index = varIndex;
+    modifier.Value = ImVec4(var->x, var->y, 0, 0);
+    *var = value;
+    m_VarStack.push_back(modifier);
+}
+
+void ed::Style::PushVar(StyleVar varIndex, const ImVec4& value)
+{
+    auto* var = GetVarVec4Addr(varIndex);
+    IM_ASSERT(var != nullptr);
+    VarModifier modifier;
+    modifier.Index = varIndex;
+    modifier.Value = *var;
+    *var = value;
+    m_VarStack.push_back(modifier);
+}
+
+void ed::Style::PopVar(int count)
+{
+    while (count > 0)
+    {
+        auto& modifier = m_VarStack.back();
+        if (auto floatValue = GetVarFloatAddr(modifier.Index))
+            *floatValue = modifier.Value.x;
+        else if (auto vec2Value = GetVarVec2Addr(modifier.Index))
+            *vec2Value = ImVec2(modifier.Value.x, modifier.Value.y);
+        else if (auto vec4Value = GetVarVec4Addr(modifier.Index))
+            *vec4Value = modifier.Value;
+        m_VarStack.pop_back();
+        --count;
+    }
+}
+
+const char* ed::Style::GetColorName(StyleColor colorIndex) const
+{
+    switch (colorIndex)
+    {
+        case StyleColor_Bg: return "Bg";
+        case StyleColor_Grid: return "Grid";
+        case StyleColor_NodeBg: return "NodeBg";
+        case StyleColor_NodeBorder: return "NodeBorder";
+        case StyleColor_HovNodeBorder: return "HoveredNodeBorder";
+        case StyleColor_SelNodeBorder: return "SelNodeBorder";
+        case StyleColor_NodeSelRect: return "NodeSelRect";
+        case StyleColor_NodeSelRectBorder: return "NodeSelRectBorder";
+        case StyleColor_HovLinkBorder: return "HoveredLinkBorder";
+        case StyleColor_SelLinkBorder: return "SelLinkBorder";
+        case StyleColor_LinkSelRect: return "LinkSelRect";
+        case StyleColor_LinkSelRectBorder: return "LinkSelRectBorder";
+        case StyleColor_PinRect: return "PinRect";
+        case StyleColor_PinRectBorder: return "PinRectBorder";
+        case StyleColor_Flow: return "Flow";
+        case StyleColor_FlowMarker: return "FlowMarker";
+        case StyleColor_GroupBg: return "GroupBg";
+        case StyleColor_GroupBorder: return "GroupBorder";
+        case StyleColor_Count: break;
+    }
+
+    IM_ASSERT(0);
+    return "Unknown";
+}
+
+float* ed::Style::GetVarFloatAddr(StyleVar idx)
+{
+    switch (idx)
+    {
+        case StyleVar_NodeRounding:             return &NodeRounding;
+        case StyleVar_NodeBorderWidth:          return &NodeBorderWidth;
+        case StyleVar_HoveredNodeBorderWidth:   return &HoveredNodeBorderWidth;
+        case StyleVar_SelectedNodeBorderWidth:  return &SelectedNodeBorderWidth;
+        case StyleVar_PinRounding:              return &PinRounding;
+        case StyleVar_PinBorderWidth:           return &PinBorderWidth;
+        case StyleVar_LinkStrength:             return &LinkStrength;
+        case StyleVar_ScrollDuration:           return &ScrollDuration;
+        case StyleVar_FlowMarkerDistance:       return &FlowMarkerDistance;
+        case StyleVar_FlowSpeed:                return &FlowSpeed;
+        case StyleVar_FlowDuration:             return &FlowDuration;
+        case StyleVar_PinCorners:               return &PinCorners;
+        case StyleVar_PinRadius:                return &PinRadius;
+        case StyleVar_PinArrowSize:             return &PinArrowSize;
+        case StyleVar_PinArrowWidth:            return &PinArrowWidth;
+        case StyleVar_GroupRounding:            return &GroupRounding;
+        case StyleVar_GroupBorderWidth:         return &GroupBorderWidth;
+        default:                                return nullptr;
+    }
+}
+
+ImVec2* ed::Style::GetVarVec2Addr(StyleVar idx)
+{
+    switch (idx)
+    {
+        case StyleVar_SourceDirection:  return &SourceDirection;
+        case StyleVar_TargetDirection:  return &TargetDirection;
+        case StyleVar_PivotAlignment:   return &PivotAlignment;
+        case StyleVar_PivotSize:        return &PivotSize;
+        case StyleVar_PivotScale:       return &PivotScale;
+        default:                        return nullptr;
+    }
+}
+
+ImVec4* ed::Style::GetVarVec4Addr(StyleVar idx)
+{
+    switch (idx)
+    {
+        case StyleVar_NodePadding:  return &NodePadding;
+        default:                    return nullptr;
+    }
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+// Config
+//
+//------------------------------------------------------------------------------
+ed::Config::Config(const ax::NodeEditor::Config* config)
+{
+    if (config)
+        *static_cast<ax::NodeEditor::Config*>(this) = *config;
+}
+
+std::string ed::Config::Load()
+{
+    std::string data;
+
+    if (LoadSettings)
+    {
+        const auto size = LoadSettings(nullptr, UserPointer);
+        if (size > 0)
+        {
+            data.resize(size);
+            LoadSettings(const_cast<char*>(data.data()), UserPointer);
+        }
+    }
+    else if (SettingsFile)
+    {
+        std::ifstream file(SettingsFile);
+        if (file)
+        {
+            file.seekg(0, std::ios_base::end);
+            auto size = static_cast<size_t>(file.tellg());
+            file.seekg(0, std::ios_base::beg);
+
+            data.reserve(size);
+            data.assign(std::istreambuf_iterator<char>(file), std::istreambuf_iterator<char>());
+        }
+    }
+
+    return data;
+}
+
+std::string ed::Config::LoadNode(NodeId nodeId)
+{
+    std::string data;
+
+    if (LoadNodeSettings)
+    {
+        const auto size = LoadNodeSettings(nodeId, nullptr, UserPointer);
+        if (size > 0)
+        {
+            data.resize(size);
+            LoadNodeSettings(nodeId, const_cast<char*>(data.data()), UserPointer);
+        }
+    }
+
+    return data;
+}
+
+void ed::Config::BeginSave()
+{
+    if (BeginSaveSession)
+        BeginSaveSession(UserPointer);
+}
+
+bool ed::Config::Save(const std::string& data, SaveReasonFlags flags)
+{
+    if (SaveSettings)
+    {
+        return SaveSettings(data.c_str(), data.size(), flags, UserPointer);
+    }
+    else if (SettingsFile)
+    {
+        std::ofstream settingsFile(SettingsFile);
+        if (settingsFile)
+            settingsFile << data;
+
+        return !!settingsFile;
+    }
+
+    return false;
+}
+
+bool ed::Config::SaveNode(NodeId nodeId, const std::string& data, SaveReasonFlags flags)
+{
+    if (SaveNodeSettings)
+        return SaveNodeSettings(nodeId, data.c_str(), data.size(), flags, UserPointer);
+
+    return false;
+}
+
+void ed::Config::EndSave()
+{
+    if (EndSaveSession)
+        EndSaveSession(UserPointer);
+}
diff --git a/3rdparty/imgui-node-editor/imgui_node_editor.h b/3rdparty/imgui-node-editor/imgui_node_editor.h
new file mode 100644
index 0000000..02282a1
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_node_editor.h
@@ -0,0 +1,444 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# ifndef __IMGUI_NODE_EDITOR_H__
+# define __IMGUI_NODE_EDITOR_H__
+# pragma once
+
+
+//------------------------------------------------------------------------------
+# include <imgui.h>
+# include <cstdint> // std::uintXX_t
+# include <utility> // std::move
+
+
+//------------------------------------------------------------------------------
+namespace ax {
+namespace NodeEditor {
+
+
+//------------------------------------------------------------------------------
+struct NodeId;
+struct LinkId;
+struct PinId;
+
+
+//------------------------------------------------------------------------------
+enum class SaveReasonFlags: uint32_t
+{
+    None       = 0x00000000,
+    Navigation = 0x00000001,
+    Position   = 0x00000002,
+    Size       = 0x00000004,
+    Selection  = 0x00000008,
+    User       = 0x00000010
+};
+
+inline SaveReasonFlags operator |(SaveReasonFlags lhs, SaveReasonFlags rhs) { return static_cast<SaveReasonFlags>(static_cast<uint32_t>(lhs) | static_cast<uint32_t>(rhs)); }
+inline SaveReasonFlags operator &(SaveReasonFlags lhs, SaveReasonFlags rhs) { return static_cast<SaveReasonFlags>(static_cast<uint32_t>(lhs) & static_cast<uint32_t>(rhs)); }
+
+using ConfigSaveSettings     = bool   (*)(const char* data, size_t size, SaveReasonFlags reason, void* userPointer);
+using ConfigLoadSettings     = size_t (*)(char* data, void* userPointer);
+
+using ConfigSaveNodeSettings = bool   (*)(NodeId nodeId, const char* data, size_t size, SaveReasonFlags reason, void* userPointer);
+using ConfigLoadNodeSettings = size_t (*)(NodeId nodeId, char* data, void* userPointer);
+
+using ConfigSession          = void   (*)(void* userPointer);
+
+struct Config
+{
+    const char*             SettingsFile;
+    ConfigSession           BeginSaveSession;
+    ConfigSession           EndSaveSession;
+    ConfigSaveSettings      SaveSettings;
+    ConfigLoadSettings      LoadSettings;
+    ConfigSaveNodeSettings  SaveNodeSettings;
+    ConfigLoadNodeSettings  LoadNodeSettings;
+    void*                   UserPointer;
+
+    Config()
+        : SettingsFile("NodeEditor.json")
+        , BeginSaveSession(nullptr)
+        , EndSaveSession(nullptr)
+        , SaveSettings(nullptr)
+        , LoadSettings(nullptr)
+        , SaveNodeSettings(nullptr)
+        , LoadNodeSettings(nullptr)
+        , UserPointer(nullptr)
+    {
+    }
+};
+
+
+//------------------------------------------------------------------------------
+enum class PinKind
+{
+    Input,
+    Output
+};
+
+
+//------------------------------------------------------------------------------
+enum StyleColor
+{
+    StyleColor_Bg,
+    StyleColor_Grid,
+    StyleColor_NodeBg,
+    StyleColor_NodeBorder,
+    StyleColor_HovNodeBorder,
+    StyleColor_SelNodeBorder,
+    StyleColor_NodeSelRect,
+    StyleColor_NodeSelRectBorder,
+    StyleColor_HovLinkBorder,
+    StyleColor_SelLinkBorder,
+    StyleColor_LinkSelRect,
+    StyleColor_LinkSelRectBorder,
+    StyleColor_PinRect,
+    StyleColor_PinRectBorder,
+    StyleColor_Flow,
+    StyleColor_FlowMarker,
+    StyleColor_GroupBg,
+    StyleColor_GroupBorder,
+
+    StyleColor_Count
+};
+
+enum StyleVar
+{
+    StyleVar_NodePadding,
+    StyleVar_NodeRounding,
+    StyleVar_NodeBorderWidth,
+    StyleVar_HoveredNodeBorderWidth,
+    StyleVar_SelectedNodeBorderWidth,
+    StyleVar_PinRounding,
+    StyleVar_PinBorderWidth,
+    StyleVar_LinkStrength,
+    StyleVar_SourceDirection,
+    StyleVar_TargetDirection,
+    StyleVar_ScrollDuration,
+    StyleVar_FlowMarkerDistance,
+    StyleVar_FlowSpeed,
+    StyleVar_FlowDuration,
+    StyleVar_PivotAlignment,
+    StyleVar_PivotSize,
+    StyleVar_PivotScale,
+    StyleVar_PinCorners,
+    StyleVar_PinRadius,
+    StyleVar_PinArrowSize,
+    StyleVar_PinArrowWidth,
+    StyleVar_GroupRounding,
+    StyleVar_GroupBorderWidth,
+
+    StyleVar_Count
+};
+
+struct Style
+{
+    ImVec4  NodePadding;
+    float   NodeRounding;
+    float   NodeBorderWidth;
+    float   HoveredNodeBorderWidth;
+    float   SelectedNodeBorderWidth;
+    float   PinRounding;
+    float   PinBorderWidth;
+    float   LinkStrength;
+    ImVec2  SourceDirection;
+    ImVec2  TargetDirection;
+    float   ScrollDuration;
+    float   FlowMarkerDistance;
+    float   FlowSpeed;
+    float   FlowDuration;
+    ImVec2  PivotAlignment;
+    ImVec2  PivotSize;
+    ImVec2  PivotScale;
+    float   PinCorners;
+    float   PinRadius;
+    float   PinArrowSize;
+    float   PinArrowWidth;
+    float   GroupRounding;
+    float   GroupBorderWidth;
+    ImVec4  Colors[StyleColor_Count];
+
+    Style()
+    {
+        NodePadding             = ImVec4(8, 8, 8, 8);
+        NodeRounding            = 12.0f;
+        NodeBorderWidth         = 1.5f;
+        HoveredNodeBorderWidth  = 3.5f;
+        SelectedNodeBorderWidth = 3.5f;
+        PinRounding             = 4.0f;
+        PinBorderWidth          = 0.0f;
+        LinkStrength            = 100.0f;
+        SourceDirection         = ImVec2(1.0f, 0.0f);
+        TargetDirection         = ImVec2(-1.0f, 0.0f);
+        ScrollDuration          = 0.35f;
+        FlowMarkerDistance      = 30.0f;
+        FlowSpeed               = 150.0f;
+        FlowDuration            = 2.0f;
+        PivotAlignment          = ImVec2(0.5f, 0.5f);
+        PivotSize               = ImVec2(0.0f, 0.0f);
+        PivotScale              = ImVec2(1, 1);
+        PinCorners              = ImDrawCornerFlags_All;
+        PinRadius               = 0.0f;
+        PinArrowSize            = 0.0f;
+        PinArrowWidth           = 0.0f;
+        GroupRounding           = 6.0f;
+        GroupBorderWidth        = 1.0f;
+
+        Colors[StyleColor_Bg]                 = ImColor( 60,  60,  70, 200);
+        Colors[StyleColor_Grid]               = ImColor(120, 120, 120,  40);
+        Colors[StyleColor_NodeBg]             = ImColor( 32,  32,  32, 200);
+        Colors[StyleColor_NodeBorder]         = ImColor(255, 255, 255,  96);
+        Colors[StyleColor_HovNodeBorder]      = ImColor( 50, 176, 255, 255);
+        Colors[StyleColor_SelNodeBorder]      = ImColor(255, 176,  50, 255);
+        Colors[StyleColor_NodeSelRect]        = ImColor(  5, 130, 255,  64);
+        Colors[StyleColor_NodeSelRectBorder]  = ImColor(  5, 130, 255, 128);
+        Colors[StyleColor_HovLinkBorder]      = ImColor( 50, 176, 255, 255);
+        Colors[StyleColor_SelLinkBorder]      = ImColor(255, 176,  50, 255);
+        Colors[StyleColor_LinkSelRect]        = ImColor(  5, 130, 255,  64);
+        Colors[StyleColor_LinkSelRectBorder]  = ImColor(  5, 130, 255, 128);
+        Colors[StyleColor_PinRect]            = ImColor( 60, 180, 255, 100);
+        Colors[StyleColor_PinRectBorder]      = ImColor( 60, 180, 255, 128);
+        Colors[StyleColor_Flow]               = ImColor(255, 128,  64, 255);
+        Colors[StyleColor_FlowMarker]         = ImColor(255, 128,  64, 255);
+        Colors[StyleColor_GroupBg]            = ImColor(  0,   0,   0, 160);
+        Colors[StyleColor_GroupBorder]        = ImColor(255, 255, 255,  32);
+    }
+};
+
+
+//------------------------------------------------------------------------------
+struct EditorContext;
+
+
+//------------------------------------------------------------------------------
+void SetCurrentEditor(EditorContext* ctx);
+EditorContext* GetCurrentEditor();
+EditorContext* CreateEditor(const Config* config = nullptr);
+void DestroyEditor(EditorContext* ctx);
+
+Style& GetStyle();
+const char* GetStyleColorName(StyleColor colorIndex);
+
+void PushStyleColor(StyleColor colorIndex, const ImVec4& color);
+void PopStyleColor(int count = 1);
+
+void PushStyleVar(StyleVar varIndex, float value);
+void PushStyleVar(StyleVar varIndex, const ImVec2& value);
+void PushStyleVar(StyleVar varIndex, const ImVec4& value);
+void PopStyleVar(int count = 1);
+
+void Begin(const char* id, const ImVec2& size = ImVec2(0, 0));
+void End();
+
+void BeginNode(NodeId id);
+void BeginPin(PinId id, PinKind kind);
+void PinRect(const ImVec2& a, const ImVec2& b);
+void PinPivotRect(const ImVec2& a, const ImVec2& b);
+void PinPivotSize(const ImVec2& size);
+void PinPivotScale(const ImVec2& scale);
+void PinPivotAlignment(const ImVec2& alignment);
+void EndPin();
+void Group(const ImVec2& size);
+void EndNode();
+
+bool BeginGroupHint(NodeId nodeId);
+ImVec2 GetGroupMin();
+ImVec2 GetGroupMax();
+ImDrawList* GetHintForegroundDrawList();
+ImDrawList* GetHintBackgroundDrawList();
+void EndGroupHint();
+
+// TODO: Add a way to manage node background channels
+ImDrawList* GetNodeBackgroundDrawList(NodeId nodeId);
+
+bool Link(LinkId id, PinId startPinId, PinId endPinId, const ImVec4& color = ImVec4(1, 1, 1, 1), float thickness = 1.0f);
+
+void Flow(LinkId linkId);
+
+bool BeginCreate(const ImVec4& color = ImVec4(1, 1, 1, 1), float thickness = 1.0f);
+bool QueryNewLink(PinId* startId, PinId* endId);
+bool QueryNewLink(PinId* startId, PinId* endId, const ImVec4& color, float thickness = 1.0f);
+bool QueryNewNode(PinId* pinId);
+bool QueryNewNode(PinId* pinId, const ImVec4& color, float thickness = 1.0f);
+bool AcceptNewItem();
+bool AcceptNewItem(const ImVec4& color, float thickness = 1.0f);
+void RejectNewItem();
+void RejectNewItem(const ImVec4& color, float thickness = 1.0f);
+void EndCreate();
+
+bool BeginDelete();
+bool QueryDeletedLink(LinkId* linkId, PinId* startId = nullptr, PinId* endId = nullptr);
+bool QueryDeletedNode(NodeId* nodeId);
+bool AcceptDeletedItem();
+void RejectDeletedItem();
+void EndDelete();
+
+void SetNodePosition(NodeId nodeId, const ImVec2& editorPosition);
+ImVec2 GetNodePosition(NodeId nodeId);
+ImVec2 GetNodeSize(NodeId nodeId);
+void CenterNodeOnScreen(NodeId nodeId);
+
+void RestoreNodeState(NodeId nodeId);
+
+void Suspend();
+void Resume();
+bool IsSuspended();
+
+bool IsActive();
+
+bool HasSelectionChanged();
+int  GetSelectedObjectCount();
+int  GetSelectedNodes(NodeId* nodes, int size);
+int  GetSelectedLinks(LinkId* links, int size);
+void ClearSelection();
+void SelectNode(NodeId nodeId, bool append = false);
+void SelectLink(LinkId linkId, bool append = false);
+void DeselectNode(NodeId nodeId);
+void DeselectLink(LinkId linkId);
+
+bool DeleteNode(NodeId nodeId);
+bool DeleteLink(LinkId linkId);
+
+void NavigateToContent(float duration = -1);
+void NavigateToSelection(bool zoomIn = false, float duration = -1);
+
+bool ShowNodeContextMenu(NodeId* nodeId);
+bool ShowPinContextMenu(PinId* pinId);
+bool ShowLinkContextMenu(LinkId* linkId);
+bool ShowBackgroundContextMenu();
+
+void EnableShortcuts(bool enable);
+bool AreShortcutsEnabled();
+
+bool BeginShortcut();
+bool AcceptCut();
+bool AcceptCopy();
+bool AcceptPaste();
+bool AcceptDuplicate();
+bool AcceptCreateNode();
+int  GetActionContextSize();
+int  GetActionContextNodes(NodeId* nodes, int size);
+int  GetActionContextLinks(LinkId* links, int size);
+void EndShortcut();
+
+float GetCurrentZoom();
+
+NodeId GetDoubleClickedNode();
+PinId GetDoubleClickedPin();
+LinkId GetDoubleClickedLink();
+bool IsBackgroundClicked();
+bool IsBackgroundDoubleClicked();
+
+bool PinHadAnyLinks(PinId pinId);
+
+ImVec2 GetScreenSize();
+ImVec2 ScreenToCanvas(const ImVec2& pos);
+ImVec2 CanvasToScreen(const ImVec2& pos);
+
+
+
+
+
+
+
+
+
+
+//------------------------------------------------------------------------------
+namespace Details {
+
+template <typename T, typename Tag>
+struct SafeType
+{
+    SafeType(T t)
+        : m_Value(std::move(t))
+    {
+    }
+
+    SafeType(const SafeType&) = default;
+
+    template <typename T2, typename Tag2>
+    SafeType(
+        const SafeType
+        <
+            typename std::enable_if<!std::is_same<T, T2>::value, T2>::type,
+            typename std::enable_if<!std::is_same<Tag, Tag2>::value, Tag2>::type
+        >&) = delete;
+
+    SafeType& operator=(const SafeType&) = default;
+
+    explicit operator T() const { return Get(); }
+
+    T Get() const { return m_Value; }
+
+private:
+    T m_Value;
+};
+
+
+template <typename Tag>
+struct SafePointerType
+    : SafeType<uintptr_t, Tag>
+{
+    static const Tag Invalid;
+
+    using SafeType<uintptr_t, Tag>::SafeType;
+
+    SafePointerType()
+        : SafePointerType(Invalid)
+    {
+    }
+
+    template <typename T = void> explicit SafePointerType(T* ptr): SafePointerType(reinterpret_cast<uintptr_t>(ptr)) {}
+    template <typename T = void> T* AsPointer() const { return reinterpret_cast<T*>(this->Get()); }
+
+    explicit operator bool() const { return *this != Invalid; }
+};
+
+template <typename Tag>
+const Tag SafePointerType<Tag>::Invalid = { 0 };
+
+template <typename Tag>
+inline bool operator==(const SafePointerType<Tag>& lhs, const SafePointerType<Tag>& rhs)
+{
+    return lhs.Get() == rhs.Get();
+}
+
+template <typename Tag>
+inline bool operator!=(const SafePointerType<Tag>& lhs, const SafePointerType<Tag>& rhs)
+{
+    return lhs.Get() != rhs.Get();
+}
+
+} // namespace Details
+
+struct NodeId final: Details::SafePointerType<NodeId>
+{
+    using SafePointerType::SafePointerType;
+};
+
+struct LinkId final: Details::SafePointerType<LinkId>
+{
+    using SafePointerType::SafePointerType;
+};
+
+struct PinId final: Details::SafePointerType<PinId>
+{
+    using SafePointerType::SafePointerType;
+};
+
+
+//------------------------------------------------------------------------------
+} // namespace Editor
+} // namespace ax
+
+
+//------------------------------------------------------------------------------
+# endif // __IMGUI_NODE_EDITOR_H__
\ No newline at end of file
diff --git a/3rdparty/imgui-node-editor/imgui_node_editor_api.cpp b/3rdparty/imgui-node-editor/imgui_node_editor_api.cpp
new file mode 100644
index 0000000..d468b4e
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_node_editor_api.cpp
@@ -0,0 +1,637 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# include "imgui_node_editor_internal.h"
+# include <algorithm>
+
+
+//------------------------------------------------------------------------------
+static ax::NodeEditor::Detail::EditorContext* s_Editor = nullptr;
+
+
+//------------------------------------------------------------------------------
+template <typename C, typename I, typename F>
+static int BuildIdList(C& container, I* list, int listSize, F&& accept)
+{
+    if (list != nullptr)
+    {
+        int count = 0;
+        for (auto object : container)
+        {
+            if (listSize <= 0)
+                break;
+
+            if (accept(object))
+            {
+                list[count] = I(object->ID().AsPointer());
+                ++count;
+                --listSize;
+            }
+        }
+
+        return count;
+    }
+    else
+        return static_cast<int>(std::count_if(container.begin(), container.end(), accept));
+}
+
+
+//------------------------------------------------------------------------------
+ax::NodeEditor::EditorContext* ax::NodeEditor::CreateEditor(const Config* config)
+{
+    return reinterpret_cast<ax::NodeEditor::EditorContext*>(new ax::NodeEditor::Detail::EditorContext(config));
+}
+
+void ax::NodeEditor::DestroyEditor(EditorContext* ctx)
+{
+    if (GetCurrentEditor() == ctx)
+        SetCurrentEditor(nullptr);
+
+    auto editor = reinterpret_cast<ax::NodeEditor::Detail::EditorContext*>(ctx);
+
+    delete editor;
+}
+
+void ax::NodeEditor::SetCurrentEditor(EditorContext* ctx)
+{
+    s_Editor = reinterpret_cast<ax::NodeEditor::Detail::EditorContext*>(ctx);
+}
+
+ax::NodeEditor::EditorContext* ax::NodeEditor::GetCurrentEditor()
+{
+    return reinterpret_cast<ax::NodeEditor::EditorContext*>(s_Editor);
+}
+
+ax::NodeEditor::Style& ax::NodeEditor::GetStyle()
+{
+    return s_Editor->GetStyle();
+}
+
+const char* ax::NodeEditor::GetStyleColorName(StyleColor colorIndex)
+{
+    return s_Editor->GetStyle().GetColorName(colorIndex);
+}
+
+void ax::NodeEditor::PushStyleColor(StyleColor colorIndex, const ImVec4& color)
+{
+    s_Editor->GetStyle().PushColor(colorIndex, color);
+}
+
+void ax::NodeEditor::PopStyleColor(int count)
+{
+    s_Editor->GetStyle().PopColor(count);
+}
+
+void ax::NodeEditor::PushStyleVar(StyleVar varIndex, float value)
+{
+    s_Editor->GetStyle().PushVar(varIndex, value);
+}
+
+void ax::NodeEditor::PushStyleVar(StyleVar varIndex, const ImVec2& value)
+{
+    s_Editor->GetStyle().PushVar(varIndex, value);
+}
+
+void ax::NodeEditor::PushStyleVar(StyleVar varIndex, const ImVec4& value)
+{
+    s_Editor->GetStyle().PushVar(varIndex, value);
+}
+
+void ax::NodeEditor::PopStyleVar(int count)
+{
+    s_Editor->GetStyle().PopVar(count);
+}
+
+void ax::NodeEditor::Begin(const char* id, const ImVec2& size)
+{
+    s_Editor->Begin(id, size);
+}
+
+void ax::NodeEditor::End()
+{
+    s_Editor->End();
+}
+
+void ax::NodeEditor::BeginNode(NodeId id)
+{
+    s_Editor->GetNodeBuilder().Begin(id);
+}
+
+void ax::NodeEditor::BeginPin(PinId id, PinKind kind)
+{
+    s_Editor->GetNodeBuilder().BeginPin(id, kind);
+}
+
+void ax::NodeEditor::PinRect(const ImVec2& a, const ImVec2& b)
+{
+    s_Editor->GetNodeBuilder().PinRect(a, b);
+}
+
+void ax::NodeEditor::PinPivotRect(const ImVec2& a, const ImVec2& b)
+{
+    s_Editor->GetNodeBuilder().PinPivotRect(a, b);
+}
+
+void ax::NodeEditor::PinPivotSize(const ImVec2& size)
+{
+    s_Editor->GetNodeBuilder().PinPivotSize(size);
+}
+
+void ax::NodeEditor::PinPivotScale(const ImVec2& scale)
+{
+    s_Editor->GetNodeBuilder().PinPivotScale(scale);
+}
+
+void ax::NodeEditor::PinPivotAlignment(const ImVec2& alignment)
+{
+    s_Editor->GetNodeBuilder().PinPivotAlignment(alignment);
+}
+
+void ax::NodeEditor::EndPin()
+{
+    s_Editor->GetNodeBuilder().EndPin();
+}
+
+void ax::NodeEditor::Group(const ImVec2& size)
+{
+    s_Editor->GetNodeBuilder().Group(size);
+}
+
+void ax::NodeEditor::EndNode()
+{
+    s_Editor->GetNodeBuilder().End();
+}
+
+bool ax::NodeEditor::BeginGroupHint(NodeId nodeId)
+{
+    return s_Editor->GetHintBuilder().Begin(nodeId);
+}
+
+ImVec2 ax::NodeEditor::GetGroupMin()
+{
+    return s_Editor->GetHintBuilder().GetGroupMin();
+}
+
+ImVec2 ax::NodeEditor::GetGroupMax()
+{
+    return s_Editor->GetHintBuilder().GetGroupMax();
+}
+
+ImDrawList* ax::NodeEditor::GetHintForegroundDrawList()
+{
+    return s_Editor->GetHintBuilder().GetForegroundDrawList();
+}
+
+ImDrawList* ax::NodeEditor::GetHintBackgroundDrawList()
+{
+    return s_Editor->GetHintBuilder().GetBackgroundDrawList();
+}
+
+void ax::NodeEditor::EndGroupHint()
+{
+    s_Editor->GetHintBuilder().End();
+}
+
+ImDrawList* ax::NodeEditor::GetNodeBackgroundDrawList(NodeId nodeId)
+{
+    if (auto node = s_Editor->FindNode(nodeId))
+        return s_Editor->GetNodeBuilder().GetUserBackgroundDrawList(node);
+    else
+        return nullptr;
+}
+
+bool ax::NodeEditor::Link(LinkId id, PinId startPinId, PinId endPinId, const ImVec4& color/* = ImVec4(1, 1, 1, 1)*/, float thickness/* = 1.0f*/)
+{
+    return s_Editor->DoLink(id, startPinId, endPinId, ImColor(color), thickness);
+}
+
+void ax::NodeEditor::Flow(LinkId linkId)
+{
+    if (auto link = s_Editor->FindLink(linkId))
+        s_Editor->Flow(link);
+}
+
+bool ax::NodeEditor::BeginCreate(const ImVec4& color, float thickness)
+{
+    auto& context = s_Editor->GetItemCreator();
+
+    if (context.Begin())
+    {
+        context.SetStyle(ImColor(color), thickness);
+        return true;
+    }
+    else
+        return false;
+}
+
+bool ax::NodeEditor::QueryNewLink(PinId* startId, PinId* endId)
+{
+    using Result = ax::NodeEditor::Detail::CreateItemAction::Result;
+
+    auto& context = s_Editor->GetItemCreator();
+
+    return context.QueryLink(startId, endId) == Result::True;
+}
+
+bool ax::NodeEditor::QueryNewLink(PinId* startId, PinId* endId, const ImVec4& color, float thickness)
+{
+    using Result = ax::NodeEditor::Detail::CreateItemAction::Result;
+
+    auto& context = s_Editor->GetItemCreator();
+
+    auto result = context.QueryLink(startId, endId);
+    if (result != Result::Indeterminate)
+        context.SetStyle(ImColor(color), thickness);
+
+    return result == Result::True;
+}
+
+bool ax::NodeEditor::QueryNewNode(PinId* pinId)
+{
+    using Result = ax::NodeEditor::Detail::CreateItemAction::Result;
+
+    auto& context = s_Editor->GetItemCreator();
+
+    return context.QueryNode(pinId) == Result::True;
+}
+
+bool ax::NodeEditor::QueryNewNode(PinId* pinId, const ImVec4& color, float thickness)
+{
+    using Result = ax::NodeEditor::Detail::CreateItemAction::Result;
+
+    auto& context = s_Editor->GetItemCreator();
+
+    auto result = context.QueryNode(pinId);
+    if (result != Result::Indeterminate)
+        context.SetStyle(ImColor(color), thickness);
+
+    return result == Result::True;
+}
+
+bool ax::NodeEditor::AcceptNewItem()
+{
+    using Result = ax::NodeEditor::Detail::CreateItemAction::Result;
+
+    auto& context = s_Editor->GetItemCreator();
+
+    return context.AcceptItem() == Result::True;
+}
+
+bool ax::NodeEditor::AcceptNewItem(const ImVec4& color, float thickness)
+{
+    using Result = ax::NodeEditor::Detail::CreateItemAction::Result;
+
+    auto& context = s_Editor->GetItemCreator();
+
+    auto result = context.AcceptItem();
+    if (result != Result::Indeterminate)
+        context.SetStyle(ImColor(color), thickness);
+
+    return result == Result::True;
+}
+
+void ax::NodeEditor::RejectNewItem()
+{
+    auto& context = s_Editor->GetItemCreator();
+
+    context.RejectItem();
+}
+
+void ax::NodeEditor::RejectNewItem(const ImVec4& color, float thickness)
+{
+    using Result = ax::NodeEditor::Detail::CreateItemAction::Result;
+
+    auto& context = s_Editor->GetItemCreator();
+
+    if (context.RejectItem() != Result::Indeterminate)
+        context.SetStyle(ImColor(color), thickness);
+}
+
+void ax::NodeEditor::EndCreate()
+{
+    auto& context = s_Editor->GetItemCreator();
+
+    context.End();
+}
+
+bool ax::NodeEditor::BeginDelete()
+{
+    auto& context = s_Editor->GetItemDeleter();
+
+    return context.Begin();
+}
+
+bool ax::NodeEditor::QueryDeletedLink(LinkId* linkId, PinId* startId, PinId* endId)
+{
+    auto& context = s_Editor->GetItemDeleter();
+
+    return context.QueryLink(linkId, startId, endId);
+}
+
+bool ax::NodeEditor::QueryDeletedNode(NodeId* nodeId)
+{
+    auto& context = s_Editor->GetItemDeleter();
+
+    return context.QueryNode(nodeId);
+}
+
+bool ax::NodeEditor::AcceptDeletedItem()
+{
+    auto& context = s_Editor->GetItemDeleter();
+
+    return context.AcceptItem();
+}
+
+void ax::NodeEditor::RejectDeletedItem()
+{
+    auto& context = s_Editor->GetItemDeleter();
+
+    context.RejectItem();
+}
+
+void ax::NodeEditor::EndDelete()
+{
+    auto& context = s_Editor->GetItemDeleter();
+
+    context.End();
+}
+
+void ax::NodeEditor::SetNodePosition(NodeId nodeId, const ImVec2& position)
+{
+    s_Editor->SetNodePosition(nodeId, position);
+}
+
+ImVec2 ax::NodeEditor::GetNodePosition(NodeId nodeId)
+{
+    return s_Editor->GetNodePosition(nodeId);
+}
+
+ImVec2 ax::NodeEditor::GetNodeSize(NodeId nodeId)
+{
+    return s_Editor->GetNodeSize(nodeId);
+}
+
+void ax::NodeEditor::CenterNodeOnScreen(NodeId nodeId)
+{
+    if (auto node = s_Editor->FindNode(nodeId))
+        node->CenterOnScreenInNextFrame();
+}
+
+void ax::NodeEditor::RestoreNodeState(NodeId nodeId)
+{
+    if (auto node = s_Editor->FindNode(nodeId))
+        s_Editor->MarkNodeToRestoreState(node);
+}
+
+void ax::NodeEditor::Suspend()
+{
+    s_Editor->Suspend();
+}
+
+void ax::NodeEditor::Resume()
+{
+    s_Editor->Resume();
+}
+
+bool ax::NodeEditor::IsSuspended()
+{
+    return s_Editor->IsSuspended();
+}
+
+bool ax::NodeEditor::IsActive()
+{
+    return s_Editor->IsActive();
+}
+
+bool ax::NodeEditor::HasSelectionChanged()
+{
+    return s_Editor->HasSelectionChanged();
+}
+
+int ax::NodeEditor::GetSelectedObjectCount()
+{
+    return (int)s_Editor->GetSelectedObjects().size();
+}
+
+int ax::NodeEditor::GetSelectedNodes(NodeId* nodes, int size)
+{
+    return BuildIdList(s_Editor->GetSelectedObjects(), nodes, size, [](auto object)
+    {
+        return object->AsNode() != nullptr;
+    });
+}
+
+int ax::NodeEditor::GetSelectedLinks(LinkId* links, int size)
+{
+    return BuildIdList(s_Editor->GetSelectedObjects(), links, size, [](auto object)
+    {
+        return object->AsLink() != nullptr;
+    });
+}
+
+void ax::NodeEditor::ClearSelection()
+{
+    s_Editor->ClearSelection();
+}
+
+void ax::NodeEditor::SelectNode(NodeId nodeId, bool append)
+{
+    if (auto node = s_Editor->FindNode(nodeId))
+    {
+        if (append)
+            s_Editor->SelectObject(node);
+        else
+            s_Editor->SetSelectedObject(node);
+    }
+}
+
+void ax::NodeEditor::SelectLink(LinkId linkId, bool append)
+{
+    if (auto link = s_Editor->FindLink(linkId))
+    {
+        if (append)
+            s_Editor->SelectObject(link);
+        else
+            s_Editor->SetSelectedObject(link);
+    }
+}
+
+void ax::NodeEditor::DeselectNode(NodeId nodeId)
+{
+    if (auto node = s_Editor->FindNode(nodeId))
+        s_Editor->DeselectObject(node);
+}
+
+void ax::NodeEditor::DeselectLink(LinkId linkId)
+{
+    if (auto link = s_Editor->FindLink(linkId))
+        s_Editor->DeselectObject(link);
+}
+
+bool ax::NodeEditor::DeleteNode(NodeId nodeId)
+{
+    if (auto node = s_Editor->FindNode(nodeId))
+        return s_Editor->GetItemDeleter().Add(node);
+    else
+        return false;
+}
+
+bool ax::NodeEditor::DeleteLink(LinkId linkId)
+{
+    if (auto link = s_Editor->FindLink(linkId))
+        return s_Editor->GetItemDeleter().Add(link);
+    else
+        return false;
+}
+
+void ax::NodeEditor::NavigateToContent(float duration)
+{
+    s_Editor->NavigateTo(s_Editor->GetContentBounds(), true, duration);
+}
+
+void ax::NodeEditor::NavigateToSelection(bool zoomIn, float duration)
+{
+    s_Editor->NavigateTo(s_Editor->GetSelectionBounds(), zoomIn, duration);
+}
+
+bool ax::NodeEditor::ShowNodeContextMenu(NodeId* nodeId)
+{
+    return s_Editor->GetContextMenu().ShowNodeContextMenu(nodeId);
+}
+
+bool ax::NodeEditor::ShowPinContextMenu(PinId* pinId)
+{
+    return s_Editor->GetContextMenu().ShowPinContextMenu(pinId);
+}
+
+bool ax::NodeEditor::ShowLinkContextMenu(LinkId* linkId)
+{
+    return s_Editor->GetContextMenu().ShowLinkContextMenu(linkId);
+}
+
+bool ax::NodeEditor::ShowBackgroundContextMenu()
+{
+    return s_Editor->GetContextMenu().ShowBackgroundContextMenu();
+}
+
+void ax::NodeEditor::EnableShortcuts(bool enable)
+{
+    s_Editor->EnableShortcuts(enable);
+}
+
+bool ax::NodeEditor::AreShortcutsEnabled()
+{
+    return s_Editor->AreShortcutsEnabled();
+}
+
+bool ax::NodeEditor::BeginShortcut()
+{
+    return s_Editor->GetShortcut().Begin();
+}
+
+bool ax::NodeEditor::AcceptCut()
+{
+    return s_Editor->GetShortcut().AcceptCut();
+}
+
+bool ax::NodeEditor::AcceptCopy()
+{
+    return s_Editor->GetShortcut().AcceptCopy();
+}
+
+bool ax::NodeEditor::AcceptPaste()
+{
+    return s_Editor->GetShortcut().AcceptPaste();
+}
+
+bool ax::NodeEditor::AcceptDuplicate()
+{
+    return s_Editor->GetShortcut().AcceptDuplicate();
+}
+
+bool ax::NodeEditor::AcceptCreateNode()
+{
+    return s_Editor->GetShortcut().AcceptCreateNode();
+}
+
+int ax::NodeEditor::GetActionContextSize()
+{
+    return static_cast<int>(s_Editor->GetShortcut().m_Context.size());
+}
+
+int ax::NodeEditor::GetActionContextNodes(NodeId* nodes, int size)
+{
+    return BuildIdList(s_Editor->GetSelectedObjects(), nodes, size, [](auto object)
+    {
+        return object->AsNode() != nullptr;
+    });
+}
+
+int ax::NodeEditor::GetActionContextLinks(LinkId* links, int size)
+{
+    return BuildIdList(s_Editor->GetSelectedObjects(), links, size, [](auto object)
+    {
+        return object->AsLink() != nullptr;
+    });
+}
+
+void ax::NodeEditor::EndShortcut()
+{
+    return s_Editor->GetShortcut().End();
+}
+
+float ax::NodeEditor::GetCurrentZoom()
+{
+    return s_Editor->GetView().InvScale;
+}
+
+ax::NodeEditor::NodeId ax::NodeEditor::GetDoubleClickedNode()
+{
+    return s_Editor->GetDoubleClickedNode();
+}
+
+ax::NodeEditor::PinId ax::NodeEditor::GetDoubleClickedPin()
+{
+    return s_Editor->GetDoubleClickedPin();
+}
+
+ax::NodeEditor::LinkId ax::NodeEditor::GetDoubleClickedLink()
+{
+    return s_Editor->GetDoubleClickedLink();
+}
+
+bool ax::NodeEditor::IsBackgroundClicked()
+{
+    return s_Editor->IsBackgroundClicked();
+}
+
+bool ax::NodeEditor::IsBackgroundDoubleClicked()
+{
+    return s_Editor->IsBackgroundDoubleClicked();
+}
+
+bool ax::NodeEditor::PinHadAnyLinks(PinId pinId)
+{
+    return s_Editor->PinHadAnyLinks(pinId);
+}
+
+ImVec2 ax::NodeEditor::GetScreenSize()
+{
+    return s_Editor->GetRect().GetSize();
+}
+
+ImVec2 ax::NodeEditor::ScreenToCanvas(const ImVec2& pos)
+{
+    return s_Editor->ToCanvas(pos);
+}
+
+ImVec2 ax::NodeEditor::CanvasToScreen(const ImVec2& pos)
+{
+    return s_Editor->ToScreen(pos);
+}
diff --git a/3rdparty/imgui-node-editor/imgui_node_editor_internal.h b/3rdparty/imgui-node-editor/imgui_node_editor_internal.h
new file mode 100644
index 0000000..cef1bd5
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_node_editor_internal.h
@@ -0,0 +1,1474 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# ifndef __IMGUI_NODE_EDITOR_INTERNAL_H__
+# define __IMGUI_NODE_EDITOR_INTERNAL_H__
+# pragma once
+
+
+//------------------------------------------------------------------------------
+# include "imgui_node_editor.h"
+
+
+//------------------------------------------------------------------------------
+# include <imgui.h>
+# define IMGUI_DEFINE_MATH_OPERATORS
+# include <imgui_internal.h>
+# include "imgui_extra_math.h"
+# include "imgui_bezier_math.h"
+# include "imgui_canvas.h"
+
+# include "crude_json.h"
+
+# include <vector>
+# include <string>
+
+
+//------------------------------------------------------------------------------
+namespace ax {
+namespace NodeEditor {
+namespace Detail {
+
+
+//------------------------------------------------------------------------------
+namespace ed = ax::NodeEditor::Detail;
+namespace json = crude_json;
+
+
+//------------------------------------------------------------------------------
+using std::vector;
+using std::string;
+
+
+//------------------------------------------------------------------------------
+void Log(const char* fmt, ...);
+
+
+//------------------------------------------------------------------------------
+//inline ImRect ToRect(const ax::rectf& rect);
+//inline ImRect ToRect(const ax::rect& rect);
+inline ImRect ImGui_GetItemRect();
+
+
+//------------------------------------------------------------------------------
+// https://stackoverflow.com/a/36079786
+# define DECLARE_HAS_MEMBER(__trait_name__, __member_name__)                         \
+                                                                                     \
+    template <typename __boost_has_member_T__>                                       \
+    class __trait_name__                                                             \
+    {                                                                                \
+        using check_type = ::std::remove_const_t<__boost_has_member_T__>;            \
+        struct no_type {char x[2];};                                                 \
+        using  yes_type = char;                                                      \
+                                                                                     \
+        struct  base { void __member_name__() {}};                                   \
+        struct mixin : public base, public check_type {};                            \
+                                                                                     \
+        template <void (base::*)()> struct aux {};                                   \
+                                                                                     \
+        template <typename U> static no_type  test(aux<&U::__member_name__>*);       \
+        template <typename U> static yes_type test(...);                             \
+                                                                                     \
+        public:                                                                      \
+                                                                                     \
+        static constexpr bool value = (sizeof(yes_type) == sizeof(test<mixin>(0)));  \
+    }
+
+DECLARE_HAS_MEMBER(HasFringeScale, _FringeScale);
+
+# undef DECLARE_HAS_MEMBER
+
+struct FringeScaleRef
+{
+    // Overload is present when ImDrawList does have _FringeScale member variable.
+    template <typename T>
+    static float& Get(typename std::enable_if<HasFringeScale<T>::value, T>::type* drawList)
+    {
+        return drawList->_FringeScale;
+    }
+
+    // Overload is present when ImDrawList does not have _FringeScale member variable.
+    template <typename T>
+    static float& Get(typename std::enable_if<!HasFringeScale<T>::value, T>::type*)
+    {
+        static float placeholder = 1.0f;
+        return placeholder;
+    }
+};
+
+static inline float& ImFringeScaleRef(ImDrawList* drawList)
+{
+    return FringeScaleRef::Get<ImDrawList>(drawList);
+}
+
+struct FringeScaleScope
+{
+
+    FringeScaleScope(float scale)
+        : m_LastFringeScale(ImFringeScaleRef(ImGui::GetWindowDrawList()))
+    {
+        ImFringeScaleRef(ImGui::GetWindowDrawList()) = scale;
+    }
+
+    ~FringeScaleScope()
+    {
+        ImFringeScaleRef(ImGui::GetWindowDrawList()) = m_LastFringeScale;
+    }
+
+private:
+    float m_LastFringeScale;
+};
+
+
+//------------------------------------------------------------------------------
+enum class ObjectType
+{
+    None,
+    Node,
+    Link,
+    Pin
+};
+
+using ax::NodeEditor::PinKind;
+using ax::NodeEditor::StyleColor;
+using ax::NodeEditor::StyleVar;
+using ax::NodeEditor::SaveReasonFlags;
+
+using ax::NodeEditor::NodeId;
+using ax::NodeEditor::PinId;
+using ax::NodeEditor::LinkId;
+
+struct ObjectId final: Details::SafePointerType<ObjectId>
+{
+    using Super = Details::SafePointerType<ObjectId>;
+    using Super::Super;
+
+    ObjectId():                  Super(Invalid),              m_Type(ObjectType::None)   {}
+    ObjectId(PinId  pinId):      Super(pinId.AsPointer()),    m_Type(ObjectType::Pin)    {}
+    ObjectId(NodeId nodeId):     Super(nodeId.AsPointer()),   m_Type(ObjectType::Node)   {}
+    ObjectId(LinkId linkId):     Super(linkId.AsPointer()),   m_Type(ObjectType::Link)   {}
+
+    explicit operator PinId()    const { return AsPinId();    }
+    explicit operator NodeId()   const { return AsNodeId();   }
+    explicit operator LinkId()   const { return AsLinkId();   }
+
+    PinId    AsPinId()    const { IM_ASSERT(IsPinId());    return PinId(AsPointer());    }
+    NodeId   AsNodeId()   const { IM_ASSERT(IsNodeId());   return NodeId(AsPointer());   }
+    LinkId   AsLinkId()   const { IM_ASSERT(IsLinkId());   return LinkId(AsPointer());   }
+
+    bool IsPinId()    const { return m_Type == ObjectType::Pin;    }
+    bool IsNodeId()   const { return m_Type == ObjectType::Node;   }
+    bool IsLinkId()   const { return m_Type == ObjectType::Link;   }
+
+    ObjectType Type() const { return m_Type; }
+
+private:
+    ObjectType m_Type;
+};
+
+struct EditorContext;
+
+struct Node;
+struct Pin;
+struct Link;
+
+template <typename T, typename Id = typename T::IdType>
+struct ObjectWrapper
+{
+    Id   m_ID;
+    T*   m_Object;
+
+          T* operator->()        { return m_Object; }
+    const T* operator->() const  { return m_Object; }
+
+    operator T*()             { return m_Object; }
+    operator const T*() const { return m_Object; }
+
+    bool operator<(const ObjectWrapper& rhs) const
+    {
+        return m_ID.AsPointer() < rhs.m_ID.AsPointer();
+    }
+};
+
+struct Object
+{
+    enum DrawFlags
+    {
+        None     = 0,
+        Hovered  = 1,
+        Selected = 2
+    };
+
+    inline friend DrawFlags operator|(DrawFlags lhs, DrawFlags rhs)  { return static_cast<DrawFlags>(static_cast<int>(lhs) | static_cast<int>(rhs)); }
+    inline friend DrawFlags operator&(DrawFlags lhs, DrawFlags rhs)  { return static_cast<DrawFlags>(static_cast<int>(lhs) & static_cast<int>(rhs)); }
+    inline friend DrawFlags& operator|=(DrawFlags& lhs, DrawFlags rhs) { lhs = lhs | rhs; return lhs; }
+    inline friend DrawFlags& operator&=(DrawFlags& lhs, DrawFlags rhs) { lhs = lhs & rhs; return lhs; }
+
+    EditorContext* const Editor;
+
+    bool    m_IsLive;
+
+    Object(EditorContext* editor)
+        : Editor(editor)
+        , m_IsLive(true)
+    {
+    }
+
+    virtual ~Object() = default;
+
+    virtual ObjectId ID() = 0;
+
+    bool IsVisible() const
+    {
+        if (!m_IsLive)
+            return false;
+
+        const auto bounds = GetBounds();
+
+        return ImGui::IsRectVisible(bounds.Min, bounds.Max);
+    }
+
+    virtual void Reset() { m_IsLive = false; }
+
+    virtual void Draw(ImDrawList* drawList, DrawFlags flags = None) = 0;
+
+    virtual bool AcceptDrag() { return false; }
+    virtual void UpdateDrag(const ImVec2& offset) { IM_UNUSED(offset); }
+    virtual bool EndDrag() { return false; }
+    virtual ImVec2 DragStartLocation() { return GetBounds().Min; }
+
+    virtual bool IsDraggable() { bool result = AcceptDrag(); EndDrag(); return result; }
+    virtual bool IsSelectable() { return false; }
+
+    virtual bool TestHit(const ImVec2& point, float extraThickness = 0.0f) const
+    {
+        if (!m_IsLive)
+            return false;
+
+        auto bounds = GetBounds();
+        if (extraThickness > 0)
+            bounds.Expand(extraThickness);
+
+        return bounds.Contains(point);
+    }
+
+    virtual bool TestHit(const ImRect& rect, bool allowIntersect = true) const
+    {
+        if (!m_IsLive)
+            return false;
+
+        const auto bounds = GetBounds();
+
+        return !ImRect_IsEmpty(bounds) && (allowIntersect ? bounds.Overlaps(rect) : rect.Contains(bounds));
+    }
+
+    virtual ImRect GetBounds() const = 0;
+
+    virtual Node*  AsNode()  { return nullptr; }
+    virtual Pin*   AsPin()   { return nullptr; }
+    virtual Link*  AsLink()  { return nullptr; }
+};
+
+struct Pin final: Object
+{
+    using IdType = PinId;
+
+    PinId   m_ID;
+    PinKind m_Kind;
+    Node*   m_Node;
+    ImRect  m_Bounds;
+    ImRect  m_Pivot;
+    Pin*    m_PreviousPin;
+    ImU32   m_Color;
+    ImU32   m_BorderColor;
+    float   m_BorderWidth;
+    float   m_Rounding;
+    int     m_Corners;
+    ImVec2  m_Dir;
+    float   m_Strength;
+    float   m_Radius;
+    float   m_ArrowSize;
+    float   m_ArrowWidth;
+    bool    m_HasConnection;
+    bool    m_HadConnection;
+
+    Pin(EditorContext* editor, PinId id, PinKind kind)
+        : Object(editor)
+        , m_ID(id)
+        , m_Kind(kind)
+        , m_Node(nullptr)
+        , m_Bounds()
+        , m_PreviousPin(nullptr)
+        , m_Color(IM_COL32_WHITE)
+        , m_BorderColor(IM_COL32_BLACK)
+        , m_BorderWidth(0)
+        , m_Rounding(0)
+        , m_Corners(0)
+        , m_Dir(0, 0)
+        , m_Strength(0)
+        , m_Radius(0)
+        , m_ArrowSize(0)
+        , m_ArrowWidth(0)
+        , m_HasConnection(false)
+        , m_HadConnection(false)
+    {
+    }
+
+    virtual ObjectId ID() override { return m_ID; }
+
+    virtual void Reset() override final
+    {
+        m_HadConnection = m_HasConnection && m_IsLive;
+        m_HasConnection = false;
+
+        Object::Reset();
+    }
+
+    virtual void Draw(ImDrawList* drawList, DrawFlags flags = None) override final;
+
+    ImVec2 GetClosestPoint(const ImVec2& p) const;
+    ImLine GetClosestLine(const Pin* pin) const;
+
+    virtual ImRect GetBounds() const override final { return m_Bounds; }
+
+    virtual Pin* AsPin() override final { return this; }
+};
+
+enum class NodeType
+{
+    Node,
+    Group
+};
+
+enum class NodeRegion : uint8_t
+{
+    None        = 0x00,
+    Top         = 0x01,
+    Bottom      = 0x02,
+    Left        = 0x04,
+    Right       = 0x08,
+    Center      = 0x10,
+    Header      = 0x20,
+    TopLeft     = Top | Left,
+    TopRight    = Top | Right,
+    BottomLeft  = Bottom | Left,
+    BottomRight = Bottom | Right,
+};
+
+inline NodeRegion operator |(NodeRegion lhs, NodeRegion rhs) { return static_cast<NodeRegion>(static_cast<uint8_t>(lhs) | static_cast<uint8_t>(rhs)); }
+inline NodeRegion operator &(NodeRegion lhs, NodeRegion rhs) { return static_cast<NodeRegion>(static_cast<uint8_t>(lhs) & static_cast<uint8_t>(rhs)); }
+
+
+struct Node final: Object
+{
+    using IdType = NodeId;
+
+    NodeId   m_ID;
+    NodeType m_Type;
+    ImRect   m_Bounds;
+    int      m_Channel;
+    Pin*     m_LastPin;
+    ImVec2   m_DragStart;
+
+    ImU32    m_Color;
+    ImU32    m_BorderColor;
+    float    m_BorderWidth;
+    float    m_Rounding;
+
+    ImU32    m_GroupColor;
+    ImU32    m_GroupBorderColor;
+    float    m_GroupBorderWidth;
+    float    m_GroupRounding;
+    ImRect   m_GroupBounds;
+
+    bool     m_RestoreState;
+    bool     m_CenterOnScreen;
+
+    Node(EditorContext* editor, NodeId id)
+        : Object(editor)
+        , m_ID(id)
+        , m_Type(NodeType::Node)
+        , m_Bounds()
+        , m_Channel(0)
+        , m_LastPin(nullptr)
+        , m_DragStart()
+        , m_Color(IM_COL32_WHITE)
+        , m_BorderColor(IM_COL32_BLACK)
+        , m_BorderWidth(0)
+        , m_Rounding(0)
+        , m_GroupBounds()
+        , m_RestoreState(false)
+        , m_CenterOnScreen(false)
+    {
+    }
+
+    virtual ObjectId ID() override { return m_ID; }
+
+    bool AcceptDrag() override;
+    void UpdateDrag(const ImVec2& offset) override;
+    bool EndDrag() override; // return true, when changed
+    ImVec2 DragStartLocation() override { return m_DragStart; }
+
+    virtual bool IsSelectable() override { return true; }
+
+    virtual void Draw(ImDrawList* drawList, DrawFlags flags = None) override final;
+    void DrawBorder(ImDrawList* drawList, ImU32 color, float thickness = 1.0f);
+
+    void GetGroupedNodes(std::vector<Node*>& result, bool append = false);
+
+    void CenterOnScreenInNextFrame() { m_CenterOnScreen = true; }
+
+    ImRect GetRegionBounds(NodeRegion region) const;
+    NodeRegion GetRegion(const ImVec2& point) const;
+
+    virtual ImRect GetBounds() const override final { return m_Bounds; }
+
+    virtual Node* AsNode() override final { return this; }
+};
+
+struct Link final: Object
+{
+    using IdType = LinkId;
+
+    LinkId m_ID;
+    Pin*   m_StartPin;
+    Pin*   m_EndPin;
+    ImU32  m_Color;
+    float  m_Thickness;
+    ImVec2 m_Start;
+    ImVec2 m_End;
+
+    Link(EditorContext* editor, LinkId id)
+        : Object(editor)
+        , m_ID(id)
+        , m_StartPin(nullptr)
+        , m_EndPin(nullptr)
+        , m_Color(IM_COL32_WHITE)
+        , m_Thickness(1.0f)
+    {
+    }
+
+    virtual ObjectId ID() override { return m_ID; }
+
+    virtual bool IsSelectable() override { return true; }
+
+    virtual void Draw(ImDrawList* drawList, DrawFlags flags = None) override final;
+    void Draw(ImDrawList* drawList, ImU32 color, float extraThickness = 0.0f) const;
+
+    void UpdateEndpoints();
+
+    ImCubicBezierPoints GetCurve() const;
+
+    virtual bool TestHit(const ImVec2& point, float extraThickness = 0.0f) const override final;
+    virtual bool TestHit(const ImRect& rect, bool allowIntersect = true) const override final;
+
+    virtual ImRect GetBounds() const override final;
+
+    virtual Link* AsLink() override final { return this; }
+};
+
+struct NodeSettings
+{
+    NodeId m_ID;
+    ImVec2 m_Location;
+    ImVec2 m_Size;
+    ImVec2 m_GroupSize;
+    bool   m_WasUsed;
+
+    bool            m_Saved;
+    bool            m_IsDirty;
+    SaveReasonFlags m_DirtyReason;
+
+    NodeSettings(NodeId id)
+        : m_ID(id)
+        , m_Location(0, 0)
+        , m_Size(0, 0)
+        , m_GroupSize(0, 0)
+        , m_WasUsed(false)
+        , m_Saved(false)
+        , m_IsDirty(false)
+        , m_DirtyReason(SaveReasonFlags::None)
+    {
+    }
+
+    void ClearDirty();
+    void MakeDirty(SaveReasonFlags reason);
+
+    json::value Serialize();
+
+    static bool Parse(const std::string& string, NodeSettings& settings);
+    static bool Parse(const json::value& data, NodeSettings& result);
+};
+
+struct Settings
+{
+    bool                 m_IsDirty;
+    SaveReasonFlags      m_DirtyReason;
+
+    vector<NodeSettings> m_Nodes;
+    vector<ObjectId>     m_Selection;
+    ImVec2               m_ViewScroll;
+    float                m_ViewZoom;
+
+    Settings()
+        : m_IsDirty(false)
+        , m_DirtyReason(SaveReasonFlags::None)
+        , m_ViewScroll(0, 0)
+        , m_ViewZoom(1.0f)
+    {
+    }
+
+    NodeSettings* AddNode(NodeId id);
+    NodeSettings* FindNode(NodeId id);
+
+    void ClearDirty(Node* node = nullptr);
+    void MakeDirty(SaveReasonFlags reason, Node* node = nullptr);
+
+    std::string Serialize();
+
+    static bool Parse(const std::string& string, Settings& settings);
+};
+
+struct Control
+{
+    Object* HotObject;
+    Object* ActiveObject;
+    Object* ClickedObject;
+    Object* DoubleClickedObject;
+    Node*   HotNode;
+    Node*   ActiveNode;
+    Node*   ClickedNode;
+    Node*   DoubleClickedNode;
+    Pin*    HotPin;
+    Pin*    ActivePin;
+    Pin*    ClickedPin;
+    Pin*    DoubleClickedPin;
+    Link*   HotLink;
+    Link*   ActiveLink;
+    Link*   ClickedLink;
+    Link*   DoubleClickedLink;
+    bool    BackgroundHot;
+    bool    BackgroundActive;
+    bool    BackgroundClicked;
+    bool    BackgroundDoubleClicked;
+
+    Control(Object* hotObject, Object* activeObject, Object* clickedObject, Object* doubleClickedObject,
+        bool backgroundHot, bool backgroundActive, bool backgroundClicked, bool backgroundDoubleClicked)
+        : HotObject(hotObject)
+        , ActiveObject(activeObject)
+        , ClickedObject(clickedObject)
+        , DoubleClickedObject(doubleClickedObject)
+        , HotNode(nullptr)
+        , ActiveNode(nullptr)
+        , ClickedNode(nullptr)
+        , DoubleClickedNode(nullptr)
+        , HotPin(nullptr)
+        , ActivePin(nullptr)
+        , ClickedPin(nullptr)
+        , DoubleClickedPin(nullptr)
+        , HotLink(nullptr)
+        , ActiveLink(nullptr)
+        , ClickedLink(nullptr)
+        , DoubleClickedLink(nullptr)
+        , BackgroundHot(backgroundHot)
+        , BackgroundActive(backgroundActive)
+        , BackgroundClicked(backgroundClicked)
+        , BackgroundDoubleClicked(backgroundDoubleClicked)
+    {
+        if (hotObject)
+        {
+            HotNode  = hotObject->AsNode();
+            HotPin   = hotObject->AsPin();
+            HotLink  = hotObject->AsLink();
+
+            if (HotPin)
+                HotNode = HotPin->m_Node;
+        }
+
+        if (activeObject)
+        {
+            ActiveNode  = activeObject->AsNode();
+            ActivePin   = activeObject->AsPin();
+            ActiveLink  = activeObject->AsLink();
+        }
+
+        if (clickedObject)
+        {
+            ClickedNode  = clickedObject->AsNode();
+            ClickedPin   = clickedObject->AsPin();
+            ClickedLink  = clickedObject->AsLink();
+        }
+
+        if (doubleClickedObject)
+        {
+            DoubleClickedNode = doubleClickedObject->AsNode();
+            DoubleClickedPin  = doubleClickedObject->AsPin();
+            DoubleClickedLink = doubleClickedObject->AsLink();
+        }
+    }
+};
+
+struct NavigateAction;
+struct SizeAction;
+struct DragAction;
+struct SelectAction;
+struct CreateItemAction;
+struct DeleteItemsAction;
+struct ContextMenuAction;
+struct ShortcutAction;
+
+struct AnimationController;
+struct FlowAnimationController;
+
+struct Animation
+{
+    enum State
+    {
+        Playing,
+        Stopped
+    };
+
+    EditorContext*  Editor;
+    State           m_State;
+    float           m_Time;
+    float           m_Duration;
+
+    Animation(EditorContext* editor);
+    virtual ~Animation();
+
+    void Play(float duration);
+    void Stop();
+    void Finish();
+    void Update();
+
+    bool IsPlaying() const { return m_State == Playing; }
+
+    float GetProgress() const { return m_Time / m_Duration; }
+
+protected:
+    virtual void OnPlay() {}
+    virtual void OnFinish() {}
+    virtual void OnStop() {}
+
+    virtual void OnUpdate(float progress) { IM_UNUSED(progress); }
+};
+
+struct NavigateAnimation final: Animation
+{
+    NavigateAction& Action;
+    ImRect      m_Start;
+    ImRect      m_Target;
+
+    NavigateAnimation(EditorContext* editor, NavigateAction& scrollAction);
+
+    void NavigateTo(const ImRect& target, float duration);
+
+private:
+    void OnUpdate(float progress) override final;
+    void OnStop() override final;
+    void OnFinish() override final;
+};
+
+struct FlowAnimation final: Animation
+{
+    FlowAnimationController* Controller;
+    Link* m_Link;
+    float m_Speed;
+    float m_MarkerDistance;
+    float m_Offset;
+
+    FlowAnimation(FlowAnimationController* controller);
+
+    void Flow(Link* link, float markerDistance, float speed, float duration);
+
+    void Draw(ImDrawList* drawList);
+
+private:
+    struct CurvePoint
+    {
+        float  Distance;
+        ImVec2 Point;
+    };
+
+    ImVec2 m_LastStart;
+    ImVec2 m_LastEnd;
+    float  m_PathLength;
+    vector<CurvePoint> m_Path;
+
+    bool IsLinkValid() const;
+    bool IsPathValid() const;
+    void UpdatePath();
+    void ClearPath();
+
+    ImVec2 SamplePath(float distance);
+
+    void OnUpdate(float progress) override final;
+    void OnStop() override final;
+};
+
+struct AnimationController
+{
+    EditorContext* Editor;
+
+    AnimationController(EditorContext* editor)
+        : Editor(editor)
+    {
+    }
+
+    virtual ~AnimationController()
+    {
+    }
+
+    virtual void Draw(ImDrawList* drawList)
+    {
+        IM_UNUSED(drawList);
+    }
+};
+
+struct FlowAnimationController final : AnimationController
+{
+    FlowAnimationController(EditorContext* editor);
+    virtual ~FlowAnimationController();
+
+    void Flow(Link* link);
+
+    virtual void Draw(ImDrawList* drawList) override final;
+
+    void Release(FlowAnimation* animation);
+
+private:
+    FlowAnimation* GetOrCreate(Link* link);
+
+    vector<FlowAnimation*> m_Animations;
+    vector<FlowAnimation*> m_FreePool;
+};
+
+struct EditorAction
+{
+    enum AcceptResult { False, True, Possible };
+
+    EditorAction(EditorContext* editor)
+        : Editor(editor)
+    {
+    }
+
+    virtual ~EditorAction() {}
+
+    virtual const char* GetName() const = 0;
+
+    virtual AcceptResult Accept(const Control& control) = 0;
+    virtual bool Process(const Control& control) = 0;
+    virtual void Reject() {} // celled when Accept return 'Possible' and was rejected
+
+    virtual ImGuiMouseCursor GetCursor() { return ImGuiMouseCursor_Arrow; }
+
+    virtual bool IsDragging() { return false; }
+
+    virtual void ShowMetrics() {}
+
+    virtual NavigateAction*     AsNavigate()     { return nullptr; }
+    virtual SizeAction*         AsSize()         { return nullptr; }
+    virtual DragAction*         AsDrag()         { return nullptr; }
+    virtual SelectAction*       AsSelect()       { return nullptr; }
+    virtual CreateItemAction*   AsCreateItem()   { return nullptr; }
+    virtual DeleteItemsAction*  AsDeleteItems()  { return nullptr; }
+    virtual ContextMenuAction*  AsContextMenu()  { return nullptr; }
+    virtual ShortcutAction* AsCutCopyPaste() { return nullptr; }
+
+    EditorContext* Editor;
+};
+
+struct NavigateAction final: EditorAction
+{
+    enum class NavigationReason
+    {
+        Unknown,
+        MouseZoom,
+        Selection,
+        Object,
+        Content,
+        Edge
+    };
+
+    bool            m_IsActive;
+    float           m_Zoom;
+    ImVec2          m_Scroll;
+    ImVec2          m_ScrollStart;
+    ImVec2          m_ScrollDelta;
+
+    NavigateAction(EditorContext* editor, ImGuiEx::Canvas& canvas);
+
+    virtual const char* GetName() const override final { return "Navigate"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+
+    virtual void ShowMetrics() override final;
+
+    virtual NavigateAction* AsNavigate() override final { return this; }
+
+    void NavigateTo(const ImRect& bounds, bool zoomIn, float duration = -1.0f, NavigationReason reason = NavigationReason::Unknown);
+    void StopNavigation();
+    void FinishNavigation();
+
+    bool MoveOverEdge();
+    void StopMoveOverEdge();
+    bool IsMovingOverEdge() const { return m_MovingOverEdge; }
+    ImVec2 GetMoveOffset() const { return m_MoveOffset; }
+
+    void SetWindow(ImVec2 position, ImVec2 size);
+
+    ImGuiEx::CanvasView GetView() const;
+    ImVec2 GetViewOrigin() const;
+    float GetViewScale() const;
+
+    void SetViewRect(const ImRect& rect);
+    ImRect GetViewRect() const;
+
+private:
+    ImGuiEx::Canvas&   m_Canvas;
+    ImVec2 m_WindowScreenPos;
+    ImVec2 m_WindowScreenSize;
+
+    NavigateAnimation  m_Animation;
+    NavigationReason   m_Reason;
+    uint64_t           m_LastSelectionId;
+    Object*            m_LastObject;
+    bool               m_MovingOverEdge;
+    ImVec2             m_MoveOffset;
+
+    bool HandleZoom(const Control& control);
+
+    void NavigateTo(const ImRect& target, float duration = -1.0f, NavigationReason reason = NavigationReason::Unknown);
+
+    float MatchZoom(int steps, float fallbackZoom);
+    int MatchZoomIndex(int direction);
+
+    static const float s_ZoomLevels[];
+    static const int   s_ZoomLevelCount;
+};
+
+struct SizeAction final: EditorAction
+{
+    bool  m_IsActive;
+    bool  m_Clean;
+    Node* m_SizedNode;
+
+    SizeAction(EditorContext* editor);
+
+    virtual const char* GetName() const override final { return "Size"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+
+    virtual ImGuiMouseCursor GetCursor() override final { return m_Cursor; }
+
+    virtual void ShowMetrics() override final;
+
+    virtual SizeAction* AsSize() override final { return this; }
+
+    virtual bool IsDragging() override final { return m_IsActive; }
+
+    const ImRect& GetStartGroupBounds() const { return m_StartGroupBounds; }
+
+private:
+    NodeRegion GetRegion(Node* node);
+    ImGuiMouseCursor ChooseCursor(NodeRegion region);
+
+    ImRect           m_StartBounds;
+    ImRect           m_StartGroupBounds;
+    ImVec2           m_LastSize;
+    ImVec2           m_MinimumSize;
+    ImVec2           m_LastDragOffset;
+    ed::NodeRegion   m_Pivot;
+    ImGuiMouseCursor m_Cursor;
+};
+
+struct DragAction final: EditorAction
+{
+    bool            m_IsActive;
+    bool            m_Clear;
+    Object*         m_DraggedObject;
+    vector<Object*> m_Objects;
+
+    DragAction(EditorContext* editor);
+
+    virtual const char* GetName() const override final { return "Drag"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+
+    virtual ImGuiMouseCursor GetCursor() override final { return ImGuiMouseCursor_ResizeAll; }
+
+    virtual bool IsDragging() override final { return m_IsActive; }
+
+    virtual void ShowMetrics() override final;
+
+    virtual DragAction* AsDrag() override final { return this; }
+};
+
+struct SelectAction final: EditorAction
+{
+    bool            m_IsActive;
+
+    bool            m_SelectGroups;
+    bool            m_SelectLinkMode;
+    bool            m_CommitSelection;
+    ImVec2          m_StartPoint;
+    ImVec2          m_EndPoint;
+    vector<Object*> m_CandidateObjects;
+    vector<Object*> m_SelectedObjectsAtStart;
+
+    Animation       m_Animation;
+
+    SelectAction(EditorContext* editor);
+
+    virtual const char* GetName() const override final { return "Select"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+
+    virtual void ShowMetrics() override final;
+
+    virtual bool IsDragging() override final { return m_IsActive; }
+
+    virtual SelectAction* AsSelect() override final { return this; }
+
+    void Draw(ImDrawList* drawList);
+};
+
+struct ContextMenuAction final: EditorAction
+{
+    enum Menu { None, Node, Pin, Link, Background };
+
+    Menu m_CandidateMenu;
+    Menu m_CurrentMenu;
+    ObjectId m_ContextId;
+
+    ContextMenuAction(EditorContext* editor);
+
+    virtual const char* GetName() const override final { return "Context Menu"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+    virtual void Reject() override final;
+
+    virtual void ShowMetrics() override final;
+
+    virtual ContextMenuAction* AsContextMenu() override final { return this; }
+
+    bool ShowNodeContextMenu(NodeId* nodeId);
+    bool ShowPinContextMenu(PinId* pinId);
+    bool ShowLinkContextMenu(LinkId* linkId);
+    bool ShowBackgroundContextMenu();
+};
+
+struct ShortcutAction final: EditorAction
+{
+    enum Action { None, Cut, Copy, Paste, Duplicate, CreateNode };
+
+    bool            m_IsActive;
+    bool            m_InAction;
+    Action          m_CurrentAction;
+    vector<Object*> m_Context;
+
+    ShortcutAction(EditorContext* editor);
+
+    virtual const char* GetName() const override final { return "Shortcut"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+    virtual void Reject() override final;
+
+    virtual void ShowMetrics() override final;
+
+    virtual ShortcutAction* AsCutCopyPaste() override final { return this; }
+
+    bool Begin();
+    void End();
+
+    bool AcceptCut();
+    bool AcceptCopy();
+    bool AcceptPaste();
+    bool AcceptDuplicate();
+    bool AcceptCreateNode();
+};
+
+struct CreateItemAction final : EditorAction
+{
+    enum Stage
+    {
+        None,
+        Possible,
+        Create
+    };
+
+    enum Action
+    {
+        Unknown,
+        UserReject,
+        UserAccept
+    };
+
+    enum Type
+    {
+        NoItem,
+        Node,
+        Link
+    };
+
+    enum Result
+    {
+        True,
+        False,
+        Indeterminate
+    };
+
+    bool      m_InActive;
+    Stage     m_NextStage;
+
+    Stage     m_CurrentStage;
+    Type      m_ItemType;
+    Action    m_UserAction;
+    ImU32     m_LinkColor;
+    float     m_LinkThickness;
+    Pin*      m_LinkStart;
+    Pin*      m_LinkEnd;
+
+    bool      m_IsActive;
+    Pin*      m_DraggedPin;
+
+    int       m_LastChannel = -1;
+
+
+    CreateItemAction(EditorContext* editor);
+
+    virtual const char* GetName() const override final { return "Create Item"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+
+    virtual ImGuiMouseCursor GetCursor() override final { return ImGuiMouseCursor_Arrow; }
+
+    virtual void ShowMetrics() override final;
+
+    virtual bool IsDragging() override final { return m_IsActive; }
+
+    virtual CreateItemAction* AsCreateItem() override final { return this; }
+
+    void SetStyle(ImU32 color, float thickness);
+
+    bool Begin();
+    void End();
+
+    Result RejectItem();
+    Result AcceptItem();
+
+    Result QueryLink(PinId* startId, PinId* endId);
+    Result QueryNode(PinId* pinId);
+
+private:
+    bool m_IsInGlobalSpace;
+
+    void DragStart(Pin* startPin);
+    void DragEnd();
+    void DropPin(Pin* endPin);
+    void DropNode();
+    void DropNothing();
+};
+
+struct DeleteItemsAction final: EditorAction
+{
+    bool    m_IsActive;
+    bool    m_InInteraction;
+
+    DeleteItemsAction(EditorContext* editor);
+
+    virtual const char* GetName() const override final { return "Delete Items"; }
+
+    virtual AcceptResult Accept(const Control& control) override final;
+    virtual bool Process(const Control& control) override final;
+
+    virtual void ShowMetrics() override final;
+
+    virtual DeleteItemsAction* AsDeleteItems() override final { return this; }
+
+    bool Add(Object* object);
+
+    bool Begin();
+    void End();
+
+    bool QueryLink(LinkId* linkId, PinId* startId = nullptr, PinId* endId = nullptr);
+    bool QueryNode(NodeId* nodeId);
+
+    bool AcceptItem();
+    void RejectItem();
+
+private:
+    enum IteratorType { Unknown, Link, Node };
+    enum UserAction { Undetermined, Accepted, Rejected };
+
+    bool QueryItem(ObjectId* itemId, IteratorType itemType);
+    void RemoveItem();
+
+    vector<Object*> m_ManuallyDeletedObjects;
+
+    IteratorType    m_CurrentItemType;
+    UserAction      m_UserAction;
+    vector<Object*> m_CandidateObjects;
+    int             m_CandidateItemIndex;
+};
+
+struct NodeBuilder
+{
+    EditorContext* const Editor;
+
+    Node* m_CurrentNode;
+    Pin*  m_CurrentPin;
+
+    ImRect m_NodeRect;
+
+    ImRect m_PivotRect;
+    ImVec2 m_PivotAlignment;
+    ImVec2 m_PivotSize;
+    ImVec2 m_PivotScale;
+    bool   m_ResolvePinRect;
+    bool   m_ResolvePivot;
+
+    ImRect m_GroupBounds;
+    bool   m_IsGroup;
+
+    ImDrawListSplitter m_Splitter;
+    ImDrawListSplitter m_PinSplitter;
+
+    NodeBuilder(EditorContext* editor);
+    ~NodeBuilder();
+
+    void Begin(NodeId nodeId);
+    void End();
+
+    void BeginPin(PinId pinId, PinKind kind);
+    void EndPin();
+
+    void PinRect(const ImVec2& a, const ImVec2& b);
+    void PinPivotRect(const ImVec2& a, const ImVec2& b);
+    void PinPivotSize(const ImVec2& size);
+    void PinPivotScale(const ImVec2& scale);
+    void PinPivotAlignment(const ImVec2& alignment);
+
+    void Group(const ImVec2& size);
+
+    ImDrawList* GetUserBackgroundDrawList() const;
+    ImDrawList* GetUserBackgroundDrawList(Node* node) const;
+};
+
+struct HintBuilder
+{
+    EditorContext* const Editor;
+    bool  m_IsActive;
+    Node* m_CurrentNode;
+    float m_LastFringe = 1.0f;
+    int   m_LastChannel = 0;
+
+    HintBuilder(EditorContext* editor);
+
+    bool Begin(NodeId nodeId);
+    void End();
+
+    ImVec2 GetGroupMin();
+    ImVec2 GetGroupMax();
+
+    ImDrawList* GetForegroundDrawList();
+    ImDrawList* GetBackgroundDrawList();
+};
+
+struct Style: ax::NodeEditor::Style
+{
+    void PushColor(StyleColor colorIndex, const ImVec4& color);
+    void PopColor(int count = 1);
+
+    void PushVar(StyleVar varIndex, float value);
+    void PushVar(StyleVar varIndex, const ImVec2& value);
+    void PushVar(StyleVar varIndex, const ImVec4& value);
+    void PopVar(int count = 1);
+
+    const char* GetColorName(StyleColor colorIndex) const;
+
+private:
+    struct ColorModifier
+    {
+        StyleColor  Index;
+        ImVec4      Value;
+    };
+
+    struct VarModifier
+    {
+        StyleVar Index;
+        ImVec4   Value;
+    };
+
+    float* GetVarFloatAddr(StyleVar idx);
+    ImVec2* GetVarVec2Addr(StyleVar idx);
+    ImVec4* GetVarVec4Addr(StyleVar idx);
+
+    vector<ColorModifier>   m_ColorStack;
+    vector<VarModifier>     m_VarStack;
+};
+
+struct Config: ax::NodeEditor::Config
+{
+    Config(const ax::NodeEditor::Config* config);
+
+    std::string Load();
+    std::string LoadNode(NodeId nodeId);
+
+    void BeginSave();
+    bool Save(const std::string& data, SaveReasonFlags flags);
+    bool SaveNode(NodeId nodeId, const std::string& data, SaveReasonFlags flags);
+    void EndSave();
+};
+
+enum class SuspendFlags : uint8_t
+{
+    None = 0,
+    KeepSplitter = 1
+};
+
+inline SuspendFlags operator |(SuspendFlags lhs, SuspendFlags rhs) { return static_cast<SuspendFlags>(static_cast<uint8_t>(lhs) | static_cast<uint8_t>(rhs)); }
+inline SuspendFlags operator &(SuspendFlags lhs, SuspendFlags rhs) { return static_cast<SuspendFlags>(static_cast<uint8_t>(lhs) & static_cast<uint8_t>(rhs)); }
+
+
+struct EditorContext
+{
+    EditorContext(const ax::NodeEditor::Config* config = nullptr);
+    ~EditorContext();
+
+    Style& GetStyle() { return m_Style; }
+
+    void Begin(const char* id, const ImVec2& size = ImVec2(0, 0));
+    void End();
+
+    bool DoLink(LinkId id, PinId startPinId, PinId endPinId, ImU32 color, float thickness);
+
+
+    NodeBuilder& GetNodeBuilder() { return m_NodeBuilder; }
+    HintBuilder& GetHintBuilder() { return m_HintBuilder; }
+
+    EditorAction* GetCurrentAction() { return m_CurrentAction; }
+
+    CreateItemAction& GetItemCreator() { return m_CreateItemAction; }
+    DeleteItemsAction& GetItemDeleter() { return m_DeleteItemsAction; }
+    ContextMenuAction& GetContextMenu() { return m_ContextMenuAction; }
+    ShortcutAction& GetShortcut() { return m_ShortcutAction; }
+
+    const ImGuiEx::CanvasView& GetView() const { return m_Canvas.View(); }
+    const ImRect& GetViewRect() const { return m_Canvas.ViewRect(); }
+    const ImRect& GetRect() const { return m_Canvas.Rect(); }
+
+    void SetNodePosition(NodeId nodeId, const ImVec2& screenPosition);
+    ImVec2 GetNodePosition(NodeId nodeId);
+    ImVec2 GetNodeSize(NodeId nodeId);
+
+    void MarkNodeToRestoreState(Node* node);
+    void RestoreNodeState(Node* node);
+
+    void ClearSelection();
+    void SelectObject(Object* object);
+    void DeselectObject(Object* object);
+    void SetSelectedObject(Object* object);
+    void ToggleObjectSelection(Object* object);
+    bool IsSelected(Object* object);
+    const vector<Object*>& GetSelectedObjects();
+    bool IsAnyNodeSelected();
+    bool IsAnyLinkSelected();
+    bool HasSelectionChanged();
+    uint64_t GetSelectionId() const { return m_SelectionId; }
+
+    Node* FindNodeAt(const ImVec2& p);
+    void FindNodesInRect(const ImRect& r, vector<Node*>& result, bool append = false, bool includeIntersecting = true);
+    void FindLinksInRect(const ImRect& r, vector<Link*>& result, bool append = false);
+
+    void FindLinksForNode(NodeId nodeId, vector<Link*>& result, bool add = false);
+
+    bool PinHadAnyLinks(PinId pinId);
+
+    ImVec2 ToCanvas(const ImVec2& point) const { return m_Canvas.ToLocal(point); }
+    ImVec2 ToScreen(const ImVec2& point) const { return m_Canvas.FromLocal(point); }
+
+    void NotifyLinkDeleted(Link* link);
+
+    void Suspend(SuspendFlags flags = SuspendFlags::None);
+    void Resume(SuspendFlags flags = SuspendFlags::None);
+    bool IsSuspended();
+
+    bool IsActive();
+
+    void MakeDirty(SaveReasonFlags reason);
+    void MakeDirty(SaveReasonFlags reason, Node* node);
+
+    Pin*    CreatePin(PinId id, PinKind kind);
+    Node*   CreateNode(NodeId id);
+    Link*   CreateLink(LinkId id);
+
+    Node*   FindNode(NodeId id);
+    Pin*    FindPin(PinId id);
+    Link*   FindLink(LinkId id);
+    Object* FindObject(ObjectId id);
+
+    Node*  GetNode(NodeId id);
+    Pin*   GetPin(PinId id, PinKind kind);
+    Link*  GetLink(LinkId id);
+
+    Link* FindLinkAt(const ImVec2& p);
+
+    template <typename T>
+    ImRect GetBounds(const std::vector<T*>& objects)
+    {
+        ImRect bounds(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX);
+
+        for (auto object : objects)
+            if (object->m_IsLive)
+                bounds.Add(object->GetBounds());
+
+        if (ImRect_IsEmpty(bounds))
+            bounds = ImRect();
+
+        return bounds;
+    }
+
+    template <typename T>
+    ImRect GetBounds(const std::vector<ObjectWrapper<T>>& objects)
+    {
+        ImRect bounds(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX);
+
+        for (auto object : objects)
+            if (object.m_Object->m_IsLive)
+                bounds.Add(object.m_Object->GetBounds());
+
+        if (ImRect_IsEmpty(bounds))
+            bounds = ImRect();
+
+        return bounds;
+    }
+
+    ImRect GetSelectionBounds() { return GetBounds(m_SelectedObjects); }
+    ImRect GetContentBounds() { return GetBounds(m_Nodes); }
+
+    ImU32 GetColor(StyleColor colorIndex) const;
+    ImU32 GetColor(StyleColor colorIndex, float alpha) const;
+
+    void NavigateTo(const ImRect& bounds, bool zoomIn = false, float duration = -1) { m_NavigateAction.NavigateTo(bounds, zoomIn, duration); }
+
+    void RegisterAnimation(Animation* animation);
+    void UnregisterAnimation(Animation* animation);
+
+    void Flow(Link* link);
+
+    void SetUserContext(bool globalSpace = false);
+
+    void EnableShortcuts(bool enable);
+    bool AreShortcutsEnabled();
+
+    NodeId GetDoubleClickedNode()      const { return m_DoubleClickedNode;       }
+    PinId  GetDoubleClickedPin()       const { return m_DoubleClickedPin;        }
+    LinkId GetDoubleClickedLink()      const { return m_DoubleClickedLink;       }
+    bool   IsBackgroundClicked()       const { return m_BackgroundClicked;       }
+    bool   IsBackgroundDoubleClicked() const { return m_BackgroundDoubleClicked; }
+
+    float AlignPointToGrid(float p) const
+    {
+        if (!ImGui::GetIO().KeyAlt)
+            return p - ImFmod(p, 16.0f);
+        else
+            return p;
+    }
+
+    ImVec2 AlignPointToGrid(const ImVec2& p) const
+    {
+        return ImVec2(AlignPointToGrid(p.x), AlignPointToGrid(p.y));
+    }
+
+private:
+    void LoadSettings();
+    void SaveSettings();
+
+    Control BuildControl(bool allowOffscreen);
+
+    void ShowMetrics(const Control& control);
+
+    void UpdateAnimations();
+
+    bool                m_IsFirstFrame;
+    bool                m_IsWindowActive;
+
+    bool                m_ShortcutsEnabled;
+
+    Style               m_Style;
+
+    vector<ObjectWrapper<Node>> m_Nodes;
+    vector<ObjectWrapper<Pin>>  m_Pins;
+    vector<ObjectWrapper<Link>> m_Links;
+
+    vector<Object*>     m_SelectedObjects;
+
+    vector<Object*>     m_LastSelectedObjects;
+    uint64_t            m_SelectionId;
+
+    Link*               m_LastActiveLink;
+
+    vector<Animation*>  m_LiveAnimations;
+    vector<Animation*>  m_LastLiveAnimations;
+
+    ImGuiEx::Canvas     m_Canvas;
+    bool                m_IsCanvasVisible;
+
+    NodeBuilder         m_NodeBuilder;
+    HintBuilder         m_HintBuilder;
+
+    EditorAction*       m_CurrentAction;
+    NavigateAction      m_NavigateAction;
+    SizeAction          m_SizeAction;
+    DragAction          m_DragAction;
+    SelectAction        m_SelectAction;
+    ContextMenuAction   m_ContextMenuAction;
+    ShortcutAction      m_ShortcutAction;
+    CreateItemAction    m_CreateItemAction;
+    DeleteItemsAction   m_DeleteItemsAction;
+
+    vector<AnimationController*> m_AnimationControllers;
+    FlowAnimationController      m_FlowAnimationController;
+
+    NodeId              m_DoubleClickedNode;
+    PinId               m_DoubleClickedPin;
+    LinkId              m_DoubleClickedLink;
+    bool                m_BackgroundClicked;
+    bool                m_BackgroundDoubleClicked;
+
+    bool                m_IsInitialized;
+    Settings            m_Settings;
+
+    Config              m_Config;
+
+    int                 m_ExternalChannel;
+    ImDrawListSplitter  m_Splitter;
+};
+
+
+//------------------------------------------------------------------------------
+} // namespace Detail
+} // namespace Editor
+} // namespace ax
+
+
+//------------------------------------------------------------------------------
+# include "imgui_node_editor_internal.inl"
+
+
+//------------------------------------------------------------------------------
+# endif // __IMGUI_NODE_EDITOR_INTERNAL_H__
diff --git a/3rdparty/imgui-node-editor/imgui_node_editor_internal.inl b/3rdparty/imgui-node-editor/imgui_node_editor_internal.inl
new file mode 100644
index 0000000..0d16231
--- /dev/null
+++ b/3rdparty/imgui-node-editor/imgui_node_editor_internal.inl
@@ -0,0 +1,55 @@
+//------------------------------------------------------------------------------
+// LICENSE
+//   This software is dual-licensed to the public domain and under the following
+//   license: you are granted a perpetual, irrevocable license to copy, modify,
+//   publish, and distribute this file as you see fit.
+//
+// CREDITS
+//   Written by Michal Cichon
+//------------------------------------------------------------------------------
+# ifndef __IMGUI_NODE_EDITOR_INTERNAL_INL__
+# define __IMGUI_NODE_EDITOR_INTERNAL_INL__
+# pragma once
+
+
+//------------------------------------------------------------------------------
+# include "imgui_node_editor_internal.h"
+
+
+//------------------------------------------------------------------------------
+namespace ax {
+namespace NodeEditor {
+namespace Detail {
+
+
+//------------------------------------------------------------------------------
+//inline ImRect ToRect(const ax::rectf& rect)
+//{
+//    return ImRect(
+//        to_imvec(rect.top_left()),
+//        to_imvec(rect.bottom_right())
+//    );
+//}
+//
+//inline ImRect ToRect(const ax::rect& rect)
+//{
+//    return ImRect(
+//        to_imvec(rect.top_left()),
+//        to_imvec(rect.bottom_right())
+//    );
+//}
+
+inline ImRect ImGui_GetItemRect()
+{
+    return ImRect(ImGui::GetItemRectMin(), ImGui::GetItemRectMax());
+}
+
+
+//------------------------------------------------------------------------------
+} // namespace Detail
+} // namespace Editor
+} // namespace ax
+
+
+//------------------------------------------------------------------------------
+# endif // __IMGUI_NODE_EDITOR_INTERNAL_INL__
diff --git a/3rdparty/imgui-node-editor/thedmd-imgui-node-editor.LICENSE.txt b/3rdparty/imgui-node-editor/thedmd-imgui-node-editor.LICENSE.txt
new file mode 100644
index 0000000..0c8aa6a
--- /dev/null
+++ b/3rdparty/imgui-node-editor/thedmd-imgui-node-editor.LICENSE.txt
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2019 Michał Cichoń
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
\ No newline at end of file
diff --git a/3rdparty/imgui-node-editor/thedmd-imgui-node-editor.stamp b/3rdparty/imgui-node-editor/thedmd-imgui-node-editor.stamp
new file mode 100644
index 0000000..8c5bdc7
--- /dev/null
+++ b/3rdparty/imgui-node-editor/thedmd-imgui-node-editor.stamp
@@ -0,0 +1,2 @@
+# This file labels the commit which our source is from
+687a72f940c76cf5064e13fe55fa0408c18fcbe4