1 files changed, 64 insertions, 26 deletions

diff --git a/src/ui.cpp b/src/ui.cpp
index aa72ac9..8e4e275 100644
--- a/src/ui.cpp
+++ b/src/ui.cpp
@@ -18,34 +18,76 @@ struct ImRect {
     ImVec2 bottom_right;
 };
 
-struct SandboxCfg {
-    int width = 40, height = 100;
-    float tile_size = 4.0f;
+/// Helpers for displaying and coordinate space tracking of the sandbox image display.
+struct SandboxDisplay {
+    float tile_size;
+    int sandbox_width = 40;
+    int sandbox_height = 100;
 
-    ImVec2 tr_sandbox2screen(ImVec2 origin, Pt pt) const {
+    ImVec2 size_screenspace;
+    ImVec2 origin;
+
+    SandboxDisplay(float tile_size, const Sandbox& sb)
+        : tile_size(tile_size)
+        , sandbox_width{ sb.width }
+        , sandbox_height{ sb.height }
+        , size_screenspace(sandbox_width * tile_size, sandbox_height * tile_size) {}
+
+    ImVec2 tr_sandbox2screen(Pt pt) const {
         return ImVec2(origin.x + tile_size * pt.x, origin.y - tile_size * pt.y);
     }
 
     // Assuming inclusive-inclusive rectangle
-    ImRect tr_sandbox2screen(ImVec2 origin, Rect r) const {
+    ImRect tr_sandbox2screen(Rect r) const {
         return {
             ImVec2(origin.x + tile_size * r.bl.x, origin.y - tile_size * (r.tr.y + 1)),
             ImVec2(origin.x + tile_size * (r.tr.x + 1), origin.y - tile_size * r.bl.y),
         };
     }
 
-    std::unique_ptr<Sandbox> make_sandbox() const {
-        return std::make_unique<Sandbox>(width, height);
+    void show_image(ImTextureID texid) {
+        auto img_topleft = ImGui::GetCursorScreenPos();
+        ImGui::Image(texid, size_screenspace, ImVec2(0, 1), ImVec2(1, 0));
+        // bottom-left corner of the sandbox, in screen space
+        origin = img_topleft;
+        origin.y += size_screenspace.y;
     }
 };
 
 void ShowEverything() {
-    ImGui::Begin("Sandbox");
+    ImGui::Begin("Options");
 
-    static SandboxCfg cfg;
-    static std::unique_ptr<Sandbox> sandbox = cfg.make_sandbox();
+    static float tile_size = 4.0f;
+    static std::unique_ptr<Sandbox> sandbox = std::make_unique<Sandbox>(40, 100);
     static OglImage gl;
 
+    ImGui::InputFloat("Tile size", &tile_size);
+
+    {
+        constexpr auto kModify = "Modify sandbox parameters";
+        static int new_width, new_height;
+
+        ImGui::Text("size = (%d, %d)", sandbox->width, sandbox->height);
+        if (ImGui::Button("Modify")) {
+            ImGui::OpenPopup(kModify);
+            new_width = sandbox->width;
+            new_height = sandbox->height;
+        }
+        if (ImGui::BeginPopup(kModify)) {
+            ImGui::InputInt("Sandbox width", &new_width);
+            ImGui::InputInt("Sandbox height", &new_height);
+            if (ImGui::Button("Confirm")) {
+                sandbox = std::make_unique<Sandbox>(new_width, new_height);
+                ImGui::CloseCurrentPopup();
+            }
+            ImGui::SameLine();
+            if (ImGui::Button("Cancel")) {
+                ImGui::CloseCurrentPopup();
+            }
+            ImGui::EndPopup();
+        }
+    }
+
     static bool running = false;
     ImGui::Checkbox("Run", &running);
     static bool show_dirty_rect = true;
@@ -59,32 +101,28 @@ void ShowEverything() {
         sandbox->simulate_step();
     }
 
-    // TODO popup for changing these params?
-    // TODO migrate existing content
-    ImGui::InputInt("Sandbox width", &cfg.width);
-    ImGui::InputInt("Sandbox height", &cfg.height);
-    if (ImGui::Button("Recreate")) {
-        sandbox = cfg.make_sandbox();
-    }
-    ImGui::SameLine();
     if (ImGui::Button("Add sand")) {
         AddSand(*sandbox);
     }
 
-    ImVec2 img_size(cfg.tile_size * sandbox->width, cfg.tile_size * sandbox->height);
-    auto img_topleft = ImGui::GetCursorScreenPos();
+    ImGui::End();
+
+    ImGui::Begin("Sandbox");
+    // Update texture to the current state of the the sandbox.
+    // Do this every frame, because it's easier than trying to track when did the sandbox change, which may be caused by:
+    // - Initialization
+    // - Simulation step
+    // - User interaction (painting, save/load, etc.)
     gl.upload(reinterpret_cast<const char*>(sandbox->bitmap), sandbox->width, sandbox->height);
-    ImGui::Image(gl.as_imgui(), img_size, ImVec2(0, 1), ImVec2(1, 0));
-    // bottom-left corner of the sandbox, in screen space
-    auto origin = img_topleft;
-    origin.y += img_size.y;
+
+    SandboxDisplay dis(tile_size, *sandbox);
+    dis.show_image(gl.as_imgui());
 
     if (show_dirty_rect) {
         auto dl = ImGui::GetWindowDrawList();
-        auto [top_left, bottom_right] = cfg.tr_sandbox2screen(origin, sandbox->dirty_writeto);
+        auto [top_left, bottom_right] = dis.tr_sandbox2screen(sandbox->dirty_writeto);
         dl->AddRect(top_left, bottom_right, IM_COL32(255, 0, 0, 255));
     }
-
     ImGui::End();
 
     ImGui::ShowDemoWindow();