From 3b3cd5ade4a7d5ef502b8256323e76bd2263dd3f Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Fri, 21 Jun 2024 23:01:32 +0200
Subject: [PATCH] Optimize Global Surface Atlas defragmenting to just reset
 tiles, not whole objects list

---
 Source/Engine/Renderer/GI/GlobalSurfaceAtlasPass.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Source/Engine/Renderer/GI/GlobalSurfaceAtlasPass.cpp b/Source/Engine/Renderer/GI/GlobalSurfaceAtlasPass.cpp
index f92e0ca52..3fd2060d9 100644
--- a/Source/Engine/Renderer/GI/GlobalSurfaceAtlasPass.cpp
+++ b/Source/Engine/Renderer/GI/GlobalSurfaceAtlasPass.cpp
@@ -268,7 +268,14 @@ public:
                 (float)AtlasPixelsUsed / AtlasPixelsTotal < maxUsageToDefrag)
             {
                 PROFILE_CPU_NAMED("Defragment Atlas");
-                ClearObjects();
+                LastFrameAtlasDefragmentation = Engine::FrameCount;
+                for (auto& e : Objects)
+                {
+                    auto& object = e.Value;
+                    Platform::MemoryClear(object.Tiles, sizeof(object.Tiles));
+                }
+                Atlas.Clear();
+                AtlasPixelsUsed = 0;
             }
         }