From 0676efd37f2b965a051c137887e223b7971e89e2 Mon Sep 17 00:00:00 2001
From: ocornut <omarcornut@gmail.com>
Date: Sun, 5 Jul 2015 22:09:55 -0600
Subject: [PATCH] AA branch: added ImDrawData::DeIndexAllBuffers() helper
 (#254)

---
 imgui.cpp | 23 +++++++++++++++++++++++
 imgui.h   |  3 +++
 2 files changed, 26 insertions(+)

diff --git a/imgui.cpp b/imgui.cpp
index 8f038008..35c3d7eb 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -9503,6 +9503,29 @@ void ImDrawList::AddImage(ImTextureID user_texture_id, const ImVec2& a, const Im
         PopTextureID();
 }
 
+//-----------------------------------------------------------------------------
+// ImDrawData
+//-----------------------------------------------------------------------------
+
+// For backward compatibility: convert all buffers from indexed to de-indexed, in case you cannot render indexed. Note: this is slow and most likely a waste of resources. Always prefer indexed rendering!
+void ImDrawData::DeIndexAllBuffers()
+{
+    ImVector<ImDrawVert> new_vtx_buffer;
+    total_vtx_count = total_idx_count = 0;
+    for (int i = 0; i < cmd_lists_count; i++)
+    {
+        ImDrawList* cmd_list = cmd_lists[i];
+        if (cmd_list->idx_buffer.empty())
+            continue;
+        new_vtx_buffer.resize(cmd_list->idx_buffer.size());
+        for (size_t i = 0; i < cmd_list->idx_buffer.size(); i++)
+            new_vtx_buffer[i] = cmd_list->vtx_buffer[cmd_list->idx_buffer[i]];
+        cmd_list->vtx_buffer.swap(new_vtx_buffer);
+        cmd_list->idx_buffer.resize(0);
+        total_vtx_count += (int)cmd_list->vtx_buffer.size();
+    }
+}
+
 //-----------------------------------------------------------------------------
 // ImFontAtlias
 //-----------------------------------------------------------------------------
diff --git a/imgui.h b/imgui.h
index 3e6150a5..e2250091 100644
--- a/imgui.h
+++ b/imgui.h
@@ -1095,6 +1095,9 @@ struct ImDrawData
     int             cmd_lists_count;
     int             total_vtx_count;        // For convenience, sum of all cmd_lists vtx_buffer.size()
     int             total_idx_count;        // For convenience, sum of all cmd_lists idx_buffer.size()
+
+    // Functions
+    void DeIndexAllBuffers();               // For backward compatibility: convert all buffers from indexed to de-indexed, in case you cannot render indexed. Note: this is slow and most likely a waste of resources. Always prefer indexed rendering!
 };
 
 // Load and rasterize multiple TTF fonts into a same texture.