ImDrawList: Store initial flags for the frame in ImDrawListSharedData, reducing code duplication in setting up the flags.

imgui.cpp

@@ -3502,16 +3502,15 @@ void ImGui::NewFrame()
     IM_ASSERT(g.Font->IsLoaded());
     g.DrawListSharedData.ClipRectFullscreen = ImVec4(0.0f, 0.0f, g.IO.DisplaySize.x, g.IO.DisplaySize.y);
     g.DrawListSharedData.CurveTessellationTol = g.Style.CurveTessellationTol;
+    g.DrawListSharedData.InitialFlags = (g.Style.AntiAliasedLines ? ImDrawListFlags_AntiAliasedLines : 0) | (g.Style.AntiAliasedFill ? ImDrawListFlags_AntiAliasedFill : 0);
 
     g.BackgroundDrawList.Clear();
     g.BackgroundDrawList.PushTextureID(g.IO.Fonts->TexID);
     g.BackgroundDrawList.PushClipRectFullScreen();
-    g.BackgroundDrawList.Flags = (g.Style.AntiAliasedLines ? ImDrawListFlags_AntiAliasedLines : 0) | (g.Style.AntiAliasedFill ? ImDrawListFlags_AntiAliasedFill : 0);
 
     g.ForegroundDrawList.Clear();
     g.ForegroundDrawList.PushTextureID(g.IO.Fonts->TexID);
     g.ForegroundDrawList.PushClipRectFullScreen();
-    g.ForegroundDrawList.Flags = (g.Style.AntiAliasedLines ? ImDrawListFlags_AntiAliasedLines : 0) | (g.Style.AntiAliasedFill ? ImDrawListFlags_AntiAliasedFill : 0);
 
     // Mark rendering data as invalid to prevent user who may have a handle on it to use it.
     g.DrawData.Clear();
@@ -5529,7 +5528,6 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
 
         // Setup draw list and outer clipping rectangle
         window->DrawList->Clear();
-        window->DrawList->Flags = (g.Style.AntiAliasedLines ? ImDrawListFlags_AntiAliasedLines : 0) | (g.Style.AntiAliasedFill ? ImDrawListFlags_AntiAliasedFill : 0);
         window->DrawList->PushTextureID(g.Font->ContainerAtlas->TexID);
         PushClipRect(host_rect.Min, host_rect.Max, false);
 

imgui.h

@@ -218,9 +218,9 @@ namespace ImGui
     IMGUI_API ImDrawData*   GetDrawData();                              // valid after Render() and until the next call to NewFrame(). this is what you have to render.
 
     // Demo, Debug, Information
-    IMGUI_API void          ShowDemoWindow(bool* p_open = NULL);        // create demo/test window (previously called ShowTestWindow). demonstrate most ImGui features. call this to learn about the library! try to make it always available in your application!
-    IMGUI_API void          ShowAboutWindow(bool* p_open = NULL);       // create about window. display Dear ImGui version, credits and build/system information.
-    IMGUI_API void          ShowMetricsWindow(bool* p_open = NULL);     // create metrics/debug window. display Dear ImGui internals: draw commands (with individual draw calls and vertices), window list, basic internal state, etc.
+    IMGUI_API void          ShowDemoWindow(bool* p_open = NULL);        // create Demo window (previously called ShowTestWindow). demonstrate most ImGui features. call this to learn about the library! try to make it always available in your application!
+    IMGUI_API void          ShowAboutWindow(bool* p_open = NULL);       // create About window. display Dear ImGui version, credits and build/system information.
+    IMGUI_API void          ShowMetricsWindow(bool* p_open = NULL);     // create Metrics/Debug window. display Dear ImGui internals: draw commands (with individual draw calls and vertices), window list, basic internal state, etc.
     IMGUI_API void          ShowStyleEditor(ImGuiStyle* ref = NULL);    // add style editor block (not a window). you can pass in a reference ImGuiStyle structure to compare to, revert to and save to (else it uses the default style)
     IMGUI_API bool          ShowStyleSelector(const char* label);       // add style selector block (not a window), essentially a combo listing the default styles.
     IMGUI_API void          ShowFontSelector(const char* label);        // add font selector block (not a window), essentially a combo listing the loaded fonts.

imgui_draw.cpp

@@ -348,6 +348,7 @@ ImDrawListSharedData::ImDrawListSharedData()
     FontSize = 0.0f;
     CurveTessellationTol = 0.0f;
     ClipRectFullscreen = ImVec4(-8192.0f, -8192.0f, +8192.0f, +8192.0f);
+    InitialFlags = ImDrawListFlags_None;
 
     // Const data
     for (int i = 0; i < IM_ARRAYSIZE(CircleVtx12); i++)
@@ -362,7 +363,7 @@ void ImDrawList::Clear()
     CmdBuffer.resize(0);
     IdxBuffer.resize(0);
     VtxBuffer.resize(0);
-    Flags = ImDrawListFlags_AntiAliasedLines | ImDrawListFlags_AntiAliasedFill;
+    Flags = _Data->InitialFlags;
     _VtxCurrentIdx = 0;
     _VtxWritePtr = NULL;
     _IdxWritePtr = NULL;

imgui_internal.h

@@ -731,6 +731,7 @@ struct IMGUI_API ImDrawListSharedData
     float           FontSize;                   // Current/default font size (optional, for simplified AddText overload)
     float           CurveTessellationTol;
     ImVec4          ClipRectFullscreen;         // Value for PushClipRectFullscreen()
+    ImDrawListFlags InitialFlags;               // Initial flags at the beginning of the frame (it is possible to alter flags on a per-drawlist basis afterwards)
 
     // Const data
     // FIXME: Bake rounded corners fill/borders in atlas
@@ -1034,7 +1035,7 @@ struct ImGuiContext
     int                     WantTextInputNextFrame;
     char                    TempBuffer[1024*3+1];               // Temporary text buffer
 
-    ImGuiContext(ImFontAtlas* shared_font_atlas) : BackgroundDrawList(NULL), ForegroundDrawList(NULL)
+    ImGuiContext(ImFontAtlas* shared_font_atlas) : BackgroundDrawList(&DrawListSharedData), ForegroundDrawList(&DrawListSharedData)
     {
         Initialized = false;
         FrameScopeActive = FrameScopePushedImplicitWindow = false;
@@ -1109,9 +1110,7 @@ struct ImGuiContext
         FocusTabPressed = false;
 
         DimBgRatio = 0.0f;
-        BackgroundDrawList._Data = &DrawListSharedData;
         BackgroundDrawList._OwnerName = "##Background"; // Give it a name for debugging
-        ForegroundDrawList._Data = &DrawListSharedData;
         ForegroundDrawList._OwnerName = "##Foreground"; // Give it a name for debugging
         MouseCursor = ImGuiMouseCursor_Arrow;