diff options
Diffstat (limited to '3rdparty/imgui-node-editor/imgui_canvas.cpp')
| -rw-r--r-- | 3rdparty/imgui-node-editor/imgui_canvas.cpp | 513 |
1 files changed, 513 insertions, 0 deletions
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(); +} |