From 0c6f1ff9dc2a0ec68ec2c2524861e9590f575685 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Thu, 3 Apr 2025 17:21:48 +0200
Subject: [PATCH] Optimize NavMesh to not allocate tile memory twice and add
 safelock to asset data

---
 Source/Engine/Content/Assets/RawDataAsset.cpp | 5 ++---
 Source/Engine/Navigation/NavMesh.cpp          | 1 +
 Source/Engine/Navigation/NavMeshData.cpp      | 2 +-
 Source/Engine/Navigation/NavMeshData.h        | 4 ++--
 Source/Engine/Navigation/NavMeshRuntime.cpp   | 9 +++++++--
 5 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/Source/Engine/Content/Assets/RawDataAsset.cpp b/Source/Engine/Content/Assets/RawDataAsset.cpp
index 5c39683da..106fd5a1b 100644
--- a/Source/Engine/Content/Assets/RawDataAsset.cpp
+++ b/Source/Engine/Content/Assets/RawDataAsset.cpp
@@ -70,9 +70,8 @@ Asset::LoadResult RawDataAsset::load()
     if (chunk0 == nullptr || chunk0->IsMissing())
         return LoadResult::MissingDataChunk;
 
-    Data.Clear();
-    Data.EnsureCapacity(chunk0->Data.Length());
-    Data.Add(chunk0->Data.Get(), chunk0->Data.Length());
+    // TODO: swap memory alloc pointer to optimize this asset
+    Data.Set(chunk0->Data.Get(), chunk0->Data.Length());
 
     return LoadResult::Ok;
 }
diff --git a/Source/Engine/Navigation/NavMesh.cpp b/Source/Engine/Navigation/NavMesh.cpp
index 7eb2b468a..772336ba3 100644
--- a/Source/Engine/Navigation/NavMesh.cpp
+++ b/Source/Engine/Navigation/NavMesh.cpp
@@ -104,6 +104,7 @@ void NavMesh::OnDataAssetLoaded()
     // Skip if already has data (prevent reloading navmesh on saving)
     if (Data.Tiles.HasItems())
         return;
+    ScopeLock lock(DataAsset->Locker);
 
     // Remove added tiles
     if (_navMeshActive)
diff --git a/Source/Engine/Navigation/NavMeshData.cpp b/Source/Engine/Navigation/NavMeshData.cpp
index c6faccc1e..fc4332e3f 100644
--- a/Source/Engine/Navigation/NavMeshData.cpp
+++ b/Source/Engine/Navigation/NavMeshData.cpp
@@ -80,7 +80,7 @@ bool NavMeshData::Load(BytesContainer& data, bool copyData)
         tile.Layer = tileHeader->Layer;
 
         // Read tile data
-        const auto tileData = stream.Move<byte>(tileHeader->DataSize);
+        const auto* tileData = (const byte*)stream.Move(tileHeader->DataSize);
         if (copyData)
             tile.Data.Copy(tileData, tileHeader->DataSize);
         else
diff --git a/Source/Engine/Navigation/NavMeshData.h b/Source/Engine/Navigation/NavMeshData.h
index 651331074..0f2a2bb7d 100644
--- a/Source/Engine/Navigation/NavMeshData.h
+++ b/Source/Engine/Navigation/NavMeshData.h
@@ -7,13 +7,13 @@
 
 class WriteStream;
 
-struct NavMeshTileDataHeader
+PACK_STRUCT(struct NavMeshTileDataHeader
 {
     int32 PosX;
     int32 PosY;
     int32 Layer;
     int32 DataSize;
-};
+});
 
 struct NavMeshTileData
 {
diff --git a/Source/Engine/Navigation/NavMeshRuntime.cpp b/Source/Engine/Navigation/NavMeshRuntime.cpp
index c4576aa53..fb42cf1ea 100644
--- a/Source/Engine/Navigation/NavMeshRuntime.cpp
+++ b/Source/Engine/Navigation/NavMeshRuntime.cpp
@@ -13,8 +13,7 @@
 
 #define MAX_NODES 2048
 #define USE_DATA_LINK 0
-#define USE_NAV_MESH_ALLOC 1
-// TODO: try not using USE_NAV_MESH_ALLOC
+#define USE_NAV_MESH_ALLOC 0
 
 namespace
 {
@@ -367,6 +366,9 @@ void NavMeshRuntime::EnsureCapacity(int32 tilesToAddCount)
         if (dtStatusFailed(result))
         {
             LOG(Warning, "Could not add tile ({2}x{3}, layer {4}) to navmesh {0} (error: {1})", Properties.Name, result & ~DT_FAILURE, tile.X, tile.Y, tile.Layer);
+#if USE_NAV_MESH_ALLOC
+            dtFree(data);
+#endif
         }
     }
 }
@@ -672,5 +674,8 @@ void NavMeshRuntime::AddTileInternal(NavMesh* navMesh, NavMeshTileData& tileData
     if (dtStatusFailed(result))
     {
         LOG(Warning, "Could not add tile ({2}x{3}, layer {4}) to navmesh {0} (error: {1})", Properties.Name, result & ~DT_FAILURE, tileData.PosX, tileData.PosY, tileData.Layer);
+#if USE_NAV_MESH_ALLOC
+        dtFree(data);
+#endif
     }
 }