From bfc0efaae9c4322557abc0146af1b3244a3a63a4 Mon Sep 17 00:00:00 2001
From: omar <omarcornut@gmail.com>
Date: Wed, 11 Apr 2018 12:43:38 +0200
Subject: [PATCH] Internals: Window: Aggregating ImDrawList into the
 ImGuiWindow structure.

---
 imgui.cpp        | 5 +++--
 imgui_internal.h | 3 ++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/imgui.cpp b/imgui.cpp
index 6b7ce2f0b..b07e7391d 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -1918,6 +1918,7 @@ bool ImGuiListClipper::Step()
 //-----------------------------------------------------------------------------
 
 ImGuiWindow::ImGuiWindow(ImGuiContext* context, const char* name)
+    : DrawListInst(&context->DrawListSharedData)
 {
     Name = ImStrdup(name);
     ID = ImHash(name, 0);
@@ -1959,7 +1960,7 @@ ImGuiWindow::ImGuiWindow(ImGuiContext* context, const char* name)
     ItemWidthDefault = 0.0f;
     FontWindowScale = 1.0f;
 
-    DrawList = IM_NEW(ImDrawList)(&context->DrawListSharedData);
+    DrawList = &DrawListInst;
     DrawList->_OwnerName = Name;
     ParentWindow = NULL;
     RootWindow = NULL;
@@ -1978,7 +1979,7 @@ ImGuiWindow::ImGuiWindow(ImGuiContext* context, const char* name)
 
 ImGuiWindow::~ImGuiWindow()
 {
-    IM_DELETE(DrawList);
+    IM_ASSERT(DrawList == &DrawListInst);
     IM_DELETE(Name);
     for (int i = 0; i != ColumnsStorage.Size; i++)
         ColumnsStorage[i].~ImGuiColumnsSet();
diff --git a/imgui_internal.h b/imgui_internal.h
index 7f0c3464b..4b512ee3e 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -943,7 +943,8 @@ struct IMGUI_API ImGuiWindow
     ImGuiStorage            StateStorage;
     ImVector<ImGuiColumnsSet> ColumnsStorage;
     float                   FontWindowScale;                    // Scale multiplier per-window
-    ImDrawList*             DrawList;
+    ImDrawList*             DrawList;                           // == &DrawListInst (for backward compatibility reason with code using imgui_internal.h we keep this a pointer)
+    ImDrawList              DrawListInst;
     ImGuiWindow*            ParentWindow;                       // If we are a child _or_ popup window, this is pointing to our parent. Otherwise NULL.
     ImGuiWindow*            RootWindow;                         // Point to ourself or first ancestor that is not a child window.
     ImGuiWindow*            RootWindowForTitleBarHighlight;     // Point to ourself or first ancestor which will display TitleBgActive color when this window is active.