SpriteRenderer, do not copy vertex array data each flush.

OpenRA.Game/Graphics/PlatformInterfaces.cs

@@ -84,6 +84,7 @@ namespace OpenRA
 	public interface IGraphicsContext : IDisposable
 	{
 		IVertexBuffer<Vertex> CreateVertexBuffer(int size);
+		Vertex[] CreateVertices(int size);
 		ITexture CreateTexture();
 		IFrameBuffer CreateFrameBuffer(Size s);
 		IFrameBuffer CreateFrameBuffer(Size s, Color clearColor);
@@ -105,6 +106,11 @@ namespace OpenRA
 	{
 		void Bind();
 		void SetData(T[] vertices, int length);
+
+		/// <summary>
+		/// Upon return `vertices` may reference another array object of at least the same size - containing random values.
+		/// </summary>
+		void SetData(ref T[] vertices, int length);
 		void SetData(T[] vertices, int offset, int start, int length);
 	}
 

OpenRA.Game/Graphics/SpriteRenderer.cs

@@ -23,7 +23,7 @@ namespace OpenRA.Graphics
 		readonly Renderer renderer;
 		readonly IShader shader;
 
-		readonly Vertex[] vertices;
+		Vertex[] vertices;
 		readonly Sheet[] sheets = new Sheet[SheetCount];
 
 		BlendMode currentBlend = BlendMode.Alpha;
@@ -34,7 +34,7 @@ namespace OpenRA.Graphics
 		{
 			this.renderer = renderer;
 			this.shader = shader;
-			vertices = new Vertex[renderer.TempBufferSize];
+			vertices = renderer.Context.CreateVertices(renderer.TempBufferSize);
 		}
 
 		public void Flush()
@@ -49,7 +49,9 @@ namespace OpenRA.Graphics
 
 				renderer.Context.SetBlendMode(currentBlend);
 				shader.PrepareRender();
-				renderer.DrawBatch(vertices, nv, PrimitiveType.TriangleList);
+
+				// PERF: The renderer may choose to replace vertices with a different temporary buffer.
+				renderer.DrawBatch(ref vertices, nv, PrimitiveType.TriangleList);
 				renderer.Context.SetBlendMode(BlendMode.None);
 
 				nv = 0;

OpenRA.Game/Renderer.cs

@@ -333,6 +333,12 @@ namespace OpenRA
 			DrawBatch(tempBuffer, 0, numVertices, type);
 		}
 
+		public void DrawBatch(ref Vertex[] vertices, int numVertices, PrimitiveType type)
+		{
+			tempBuffer.SetData(ref vertices, numVertices);
+			DrawBatch(tempBuffer, 0, numVertices, type);
+		}
+
 		public void DrawBatch<T>(IVertexBuffer<T> vertices,
 			int firstVertex, int numVertices, PrimitiveType type)
 			where T : struct

OpenRA.Platforms.Default/Sdl2GraphicsContext.cs

@@ -67,6 +67,12 @@ namespace OpenRA.Platforms.Default
 			return new VertexBuffer<Vertex>(size);
 		}
 
+		public Vertex[] CreateVertices(int size)
+		{
+			VerifyThreadAffinity();
+			return new Vertex[size];
+		}
+
 		public ITexture CreateTexture()
 		{
 			VerifyThreadAffinity();

OpenRA.Platforms.Default/ThreadedGraphicsContext.cs

@@ -404,6 +404,11 @@ namespace OpenRA.Platforms.Default
 			return Send(getCreateVertexBuffer, length);
 		}
 
+		public Vertex[] CreateVertices(int size)
+		{
+			return GetVertices(size);
+		}
+
 		public void DisableDepthBuffer()
 		{
 			Post(doDisableDepthBuffer);
@@ -526,6 +531,16 @@ namespace OpenRA.Platforms.Default
 			device.Post(setData1, (buffer, length));
 		}
 
+		/// <summary>
+		/// PERF: The vertices array is passed without copying to the render thread. Upon return `vertices` may reference another
+		/// array object of at least the same size - containing random values.
+		/// </summary>
+		public void SetData(ref Vertex[] vertices, int length)
+		{
+			device.Post(setData1, (vertices, length));
+			vertices = device.GetVertices(vertices.Length);
+		}
+
 		public void SetData(Vertex[] vertices, int offset, int start, int length)
 		{
 			if (length <= device.BatchSize)

OpenRA.Platforms.Default/VertexBuffer.cs

@@ -60,6 +60,11 @@ namespace OpenRA.Platforms.Default
 			SetData(data, 0, 0, length);
 		}
 
+		public void SetData(ref T[] data, int length)
+		{
+			SetData(data, 0, 0, length);
+		}
+
 		public void SetData(T[] data, int offset, int start, int length)
 		{
 			Bind();