Added ImGuiCorner enum to clarify some internal code

imgui.cpp

@@ -4192,8 +4192,7 @@ bool ImGui::Begin(const char* name, bool* p_open, const ImVec2& size_on_first_us
             window->ScrollbarSizes = ImVec2(window->ScrollbarY ? style.ScrollbarSize : 0.0f, window->ScrollbarX ? style.ScrollbarSize : 0.0f);
             window->BorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f;
 
-            // Window background
-            // Default alpha
+            // Window background, Default Alpha
             ImGuiCol bg_color_idx = ImGuiCol_WindowBg;
             if ((flags & ImGuiWindowFlags_ComboBox) != 0)
                 bg_color_idx = ImGuiCol_ComboBg;
@@ -4206,19 +4205,19 @@ bool ImGui::Begin(const char* name, bool* p_open, const ImVec2& size_on_first_us
                 bg_color.w = bg_alpha;
             bg_color.w *= style.Alpha;
             if (bg_color.w > 0.0f)
-                window->DrawList->AddRectFilled(window->Pos+ImVec2(0,window->TitleBarHeight()), window->Pos+window->Size, ColorConvertFloat4ToU32(bg_color), window_rounding, (flags & ImGuiWindowFlags_NoTitleBar) ? 15 : 4|8);
+                window->DrawList->AddRectFilled(window->Pos+ImVec2(0,window->TitleBarHeight()), window->Pos+window->Size, ColorConvertFloat4ToU32(bg_color), window_rounding, (flags & ImGuiWindowFlags_NoTitleBar) ? ImGuiCorner_All : ImGuiCorner_BottomLeft|ImGuiCorner_BottomRight);
 
             // Title bar
             if (!(flags & ImGuiWindowFlags_NoTitleBar))
-                window->DrawList->AddRectFilled(title_bar_rect.GetTL(), title_bar_rect.GetBR(), GetColorU32((g.FocusedWindow && window->RootNonPopupWindow == g.FocusedWindow->RootNonPopupWindow) ? ImGuiCol_TitleBgActive : ImGuiCol_TitleBg), window_rounding, 1|2);
+                window->DrawList->AddRectFilled(title_bar_rect.GetTL(), title_bar_rect.GetBR(), GetColorU32((g.FocusedWindow && window->RootNonPopupWindow == g.FocusedWindow->RootNonPopupWindow) ? ImGuiCol_TitleBgActive : ImGuiCol_TitleBg), window_rounding, ImGuiCorner_TopLeft|ImGuiCorner_TopRight);
 
             // Menu bar
             if (flags & ImGuiWindowFlags_MenuBar)
             {
                 ImRect menu_bar_rect = window->MenuBarRect();
-                window->DrawList->AddRectFilled(menu_bar_rect.GetTL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_MenuBarBg), (flags & ImGuiWindowFlags_NoTitleBar) ? window_rounding : 0.0f, 1|2);
                 if (flags & ImGuiWindowFlags_ShowBorders)
                     window->DrawList->AddLine(menu_bar_rect.GetBL()-ImVec2(0,0), menu_bar_rect.GetBR()-ImVec2(0,0), GetColorU32(ImGuiCol_Border));
+                window->DrawList->AddRectFilled(menu_bar_rect.GetTL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_MenuBarBg), (flags & ImGuiWindowFlags_NoTitleBar) ? window_rounding : 0.0f, ImGuiCorner_TopLeft|ImGuiCorner_TopRight);
             }
 
             // Scrollbars
@@ -4426,9 +4425,9 @@ static void Scrollbar(ImGuiWindow* window, bool horizontal)
     float window_rounding = (window->Flags & ImGuiWindowFlags_ChildWindow) ? style.ChildWindowRounding : style.WindowRounding;
     int window_rounding_corners;
     if (horizontal)
-        window_rounding_corners = 8 | (other_scrollbar ? 0 : 4);
+        window_rounding_corners = ImGuiCorner_BottomLeft | (other_scrollbar ? 0 : ImGuiCorner_BottomRight);
     else
-        window_rounding_corners = (((window->Flags & ImGuiWindowFlags_NoTitleBar) && !(window->Flags & ImGuiWindowFlags_MenuBar)) ? 2 : 0) | (other_scrollbar ? 0 : 4);
+        window_rounding_corners = (((window->Flags & ImGuiWindowFlags_NoTitleBar) && !(window->Flags & ImGuiWindowFlags_MenuBar)) ? ImGuiCorner_TopRight : 0) | (other_scrollbar ? 0 : ImGuiCorner_BottomRight);
     window->DrawList->AddRectFilled(bb.Min, bb.Max, ImGui::GetColorU32(ImGuiCol_ScrollbarBg), window_rounding, window_rounding_corners);
     bb.Reduce(ImVec2(ImClamp((float)(int)((bb.Max.x - bb.Min.x - 2.0f) * 0.5f), 0.0f, 3.0f), ImClamp((float)(int)((bb.Max.y - bb.Min.y - 2.0f) * 0.5f), 0.0f, 3.0f)));
 

imgui_internal.h

@@ -197,6 +197,15 @@ enum ImGuiDataType
     ImGuiDataType_Float2,
 };
 
+enum ImGuiCorner
+{
+    ImGuiCorner_TopLeft     = 1 << 0, // 1
+    ImGuiCorner_TopRight    = 1 << 1, // 2
+    ImGuiCorner_BottomRight = 1 << 2, // 4
+    ImGuiCorner_BottomLeft  = 1 << 3, // 8
+    ImGuiCorner_All         = 0x0F
+};
+
 // 2D axis aligned bounding-box
 // NB: we can't rely on ImVec2 math operators being available here
 struct IMGUI_API ImRect