Viewport: Exposed GetOverlayDrawList(ImGuiViewport* viewport) in public API. (#1542, #1660, #1878, etc.)

imgui.cpp

@@ -2919,10 +2919,11 @@ int ImGui::GetFrameCount()
     return GImGui->FrameCount;
 }
 
-ImDrawList* ImGui::GetOverlayDrawList(ImGuiViewportP* viewport)
+ImDrawList* ImGui::GetOverlayDrawList(ImGuiViewport* viewport_public)
 {
     // Create the draw list on demand, because it is not frequently used for all viewports
     ImGuiContext& g = *GImGui;
+    ImGuiViewportP* viewport = (ImGuiViewportP*)viewport_public;
     if (viewport->OverlayDrawList == NULL)
     {
         viewport->OverlayDrawList = IM_NEW(ImDrawList)(&g.DrawListSharedData);

imgui.h

@@ -558,7 +558,8 @@ namespace ImGui
     IMGUI_API bool          IsRectVisible(const ImVec2& rect_min, const ImVec2& rect_max);      // test if rectangle (in screen space) is visible / not clipped. to perform coarse clipping on user's side.
     IMGUI_API double        GetTime();
     IMGUI_API int           GetFrameCount();
-    IMGUI_API ImDrawList*   GetOverlayDrawList();                                               // this draw list will be the last rendered. it covers the entire current viewport. useful to quickly draw overlays shapes/text
+    IMGUI_API ImDrawList*   GetOverlayDrawList();                                               // get overlay draw list for the viewport associated to the current window. this draw list will be the last rendered. useful to quickly draw overlays shapes/text.
+    IMGUI_API ImDrawList*   GetOverlayDrawList(ImGuiViewport* viewport);                        // get overlay draw list for the given viewport. 
     IMGUI_API ImDrawListSharedData* GetDrawListSharedData();                                    // you may use this when creating your own ImDrawList instances
     IMGUI_API const char*   GetStyleColorName(ImGuiCol idx);
     IMGUI_API void          SetStateStorage(ImGuiStorage* storage);                             // replace current window storage with our own (if you want to manipulate it yourself, typically clear subsection of it)

imgui_internal.h

@@ -1189,7 +1189,6 @@ namespace ImGui
 
     IMGUI_API void          SetCurrentFont(ImFont* font);
     inline ImFont*          GetDefaultFont() { ImGuiContext& g = *GImGui; return g.IO.FontDefault ? g.IO.FontDefault : g.IO.Fonts->Fonts[0]; }
-    IMGUI_API ImDrawList*   GetOverlayDrawList(ImGuiViewportP* viewport);
     inline ImDrawList*      GetOverlayDrawList(ImGuiWindow* window) { return GetOverlayDrawList(window->Viewport); }
 
     // Init