Comments about limiting WindowRounding to a reasonable size.

imgui.cpp

@@ -1008,7 +1008,7 @@ ImGuiStyle::ImGuiStyle()
 {
     Alpha                   = 1.0f;             // Global alpha applies to everything in ImGui
     WindowPadding           = ImVec2(8,8);      // Padding within a window
-    WindowRounding          = 7.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    WindowRounding          = 7.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows. Large values tend to lead to variety of artifacts and are not recommended.
     WindowBorderSize        = 1.0f;             // Thickness of border around windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowTitleAlign        = ImVec2(0.0f,0.5f);// Alignment for title bar text
@@ -5757,8 +5757,13 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->Pos = ImFloor(window->Pos);
 
         // Lock window rounding for the frame (so that altering them doesn't cause inconsistencies)
+        // Large values tend to lead to variety of artifacts and are not recommended.
         window->WindowRounding = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildRounding : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupRounding : style.WindowRounding;
 
+        // For windows with title bar or menu bar, we clamp to FrameHeight(FontSize + FramePadding.y * 2.0f) to completely hide artifacts.
+        //if ((window->Flags & ImGuiWindowFlags_MenuBar) || !(window->Flags & ImGuiWindowFlags_NoTitleBar))
+        //    window->WindowRounding = ImMin(window->WindowRounding, g.FontSize + style.FramePadding.y * 2.0f);
+
         // Apply window focus (new and reactivated windows are moved to front)
         bool want_focus = false;
         if (window_just_activated_by_user && !(flags & ImGuiWindowFlags_NoFocusOnAppearing))

imgui.h

@@ -1371,7 +1371,7 @@ struct ImGuiStyle
 {
     float       Alpha;                      // Global alpha applies to everything in Dear ImGui.
     ImVec2      WindowPadding;              // Padding within a window.
-    float       WindowRounding;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows.
+    float       WindowRounding;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows. Large values tend to lead to variety of artifacts and are not recommended.
     float       WindowBorderSize;           // Thickness of border around windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly).
     ImVec2      WindowMinSize;              // Minimum window size. This is a global setting. If you want to constraint individual windows, use SetNextWindowSizeConstraints().
     ImVec2      WindowTitleAlign;           // Alignment for title bar text. Defaults to (0.0f,0.5f) for left-aligned,vertically centered.

imgui_internal.h

@@ -1561,7 +1561,7 @@ struct IMGUI_API ImGuiWindow
     ImVec2                  ContentSize;                        // Size of contents/scrollable client area (calculated from the extents reach of the cursor) from previous frame. Does not include window decoration or window padding.
     ImVec2                  ContentSizeExplicit;                // Size of contents/scrollable client area explicitly request by the user via SetNextWindowContentSize().
     ImVec2                  WindowPadding;                      // Window padding at the time of Begin().
-    float                   WindowRounding;                     // Window rounding at the time of Begin().
+    float                   WindowRounding;                     // Window rounding at the time of Begin(). May be clamped lower to avoid rendering artifacts with title bar, menu bar etc.
     float                   WindowBorderSize;                   // Window border size at the time of Begin().
     int                     NameBufLen;                         // Size of buffer storing Name. May be larger than strlen(Name)!
     ImGuiID                 MoveId;                             // == window->GetID("#MOVE")