Optimize DrawBatch for faster sorting

Source/Engine/Renderer/RenderList.cpp

@@ -570,6 +570,7 @@ void RenderList::SortDrawCalls(const RenderContext& renderContext, bool reverseD
     const auto* drawCallsData = drawCalls.Get();
     const auto* listData = list.Indices.Get();
     const int32 listSize = list.Indices.Count();
+    ZoneValue(listSize);
 
     // Peek shared memory
 #define PREPARE_CACHE(list) (list).Clear(); (list).Resize(listSize)
@@ -626,6 +627,7 @@ void RenderList::SortDrawCalls(const RenderContext& renderContext, bool reverseD
         }
 
         DrawBatch batch;
+        static_assert(sizeof(DrawBatch) == sizeof(uint64) * 2, "Fix the size of draw batch to optimize memory access.");
         batch.SortKey = sortedKeys[i];
         batch.StartIndex = i;
         batch.BatchSize = batchSize;

Source/Engine/Renderer/RenderList.h

@@ -212,17 +212,17 @@ struct DrawBatch
     /// <summary>
     /// The first draw call index.
     /// </summary>
-    int32 StartIndex;
+    uint16 StartIndex;
 
     /// <summary>
     /// A number of draw calls to be submitted at once.
     /// </summary>
-    int32 BatchSize;
+    uint16 BatchSize;
 
     /// <summary>
     /// The total amount of instances (sum from all draw calls in this batch).
     /// </summary>
-    int32 InstanceCount;
+    uint32 InstanceCount;
 
     bool operator<(const DrawBatch& other) const
     {