Windows: Changed default ClipRect to extend to windows' left and right borders. (#3312, #7540, #3756, #6170, #6365)

Author: ocornut

docs/CHANGELOG.txt

@@ -56,6 +56,12 @@ Breaking changes:
 
 Other changes:
 
+- Windows: Changed default ClipRect to extend to windows' left and right borders,
+  instead of adding arbitrary WindowPadding.x * 0.5f space on left and right.
+  That ClipRect half-padding was arbitrary/confusing and inconsistent with Y axis.
+  It also made it harder to draw items covering whole window without pushing an
+  extended ClipRect. Some items near windows left and right edge that used to be clipped
+  may be partly more visible. (#3312, #7540, #3756, #6170, #6365)
 - Windows: Fixed subsequent Begin() append calls from setting last item information
   for title bar, making it impossible to use IsItemHovered() on a Begin()-to-append,
   and causing issue bypassing hover detection on collapsed windows. (#7506, #823)

imgui.cpp

@@ -6838,16 +6838,18 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->InnerRect.Max.y = window->Pos.y + window->Size.y - window->DecoOuterSizeY2;
 
         // Inner clipping rectangle.
-        // Will extend a little bit outside the normal work region.
-        // This is to allow e.g. Selectable or CollapsingHeader or some separators to cover that space.
-        // Force round operator last to ensure that e.g. (int)(max.x-min.x) in user's render code produce correct result.
+        // - Extend a outside of normal work region up to borders.
+        // - This is to allow e.g. Selectable or CollapsingHeader or some separators to cover that space.
+        // - It also makes clipped items be more noticeable.
+        // - And is consistent on both axis (prior to 2024/05/03 ClipRect used WindowPadding.x * 0.5f on left and right edge), see #3312
+        // - Force round operator last to ensure that e.g. (int)(max.x-min.x) in user's render code produce correct result.
         // Note that if our window is collapsed we will end up with an inverted (~null) clipping rectangle which is the correct behavior.
         // Affected by window/frame border size. Used by:
         // - Begin() initial clip rect
         float top_border_size = (((flags & ImGuiWindowFlags_MenuBar) || !(flags & ImGuiWindowFlags_NoTitleBar)) ? style.FrameBorderSize : window->WindowBorderSize);
-        window->InnerClipRect.Min.x = ImFloor(0.5f + window->InnerRect.Min.x + ImMax(ImTrunc(window->WindowPadding.x * 0.5f), window->WindowBorderSize));
+        window->InnerClipRect.Min.x = ImFloor(0.5f + window->InnerRect.Min.x + window->WindowBorderSize);
         window->InnerClipRect.Min.y = ImFloor(0.5f + window->InnerRect.Min.y + top_border_size);
-        window->InnerClipRect.Max.x = ImFloor(0.5f + window->InnerRect.Max.x - ImMax(ImTrunc(window->WindowPadding.x * 0.5f), window->WindowBorderSize));
+        window->InnerClipRect.Max.x = ImFloor(0.5f + window->InnerRect.Max.x - window->WindowBorderSize);
         window->InnerClipRect.Max.y = ImFloor(0.5f + window->InnerRect.Max.y - window->WindowBorderSize);
         window->InnerClipRect.ClipWithFull(host_rect);
 

imgui.h

@@ -28,7 +28,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
 #define IMGUI_VERSION       "1.90.6 WIP"
-#define IMGUI_VERSION_NUM   19053
+#define IMGUI_VERSION_NUM   19054
 #define IMGUI_HAS_TABLE
 
 /*