anchor.diff:                  else Option.get envOpt // guaranteed to exist
   
               let vertexSize = nativeint sizeof<SpriteBatchVertex>
  -            let cpuOffset = env.CpuBuffer + vertexSize * nativeint 4
  +            let cpuOffset = env.CpuBuffer + nativeint env.SpriteIndex * vertexSize * nativeint 4
               let position0 = (position - center).Rotate rotation
  -            let mutable vertex0 = Marshal.PtrToStructure<SpriteBatchVertex> cpuOffset
  +            let mutable vertex0 = Unchecked.defaultof<SpriteBatchVertex>
               vertex0.SbvPosition <- position0
               vertex0.SbvCoord <- coords.BottomLeft
               vertex0.SbvColor <- color
               Marshal.StructureToPtr<SpriteBatchVertex> (vertex0, cpuOffset, false)
   
  +            let test = Marshal.PtrToStructure<SpriteBatchVertex> env.CpuBuffer
  +
               let cpuOffset = cpuOffset + vertexSize
               let position1Unrotated = v2 (position.X + size.X) position.Y
               let position1 = (position1Unrotated - center).Rotate rotation
  -            let mutable vertex1 = Marshal.PtrToStructure<SpriteBatchVertex> cpuOffset
  +            let mutable vertex1 = Unchecked.defaultof<SpriteBatchVertex>
               vertex1.SbvPosition <- position1
               vertex1.SbvCoord <- coords.BottomRight
               vertex1.SbvColor <- color
  
positive.code:             match envOpt with
              | Some env ->
                  if env.SpriteIndex > 0 then
                      EndSpriteBatch ()
                      RenderSpriteBatch env.SpriteIndex env.SpriteTexUniform env.SpriteProgram env.BatchState.Texture env.CpuBuffer env.GpuBuffer env.GpuVao
              | None -> ()
  
          let RenderSprite center (position : Vector2) (size : Vector2) rotation color (coords : Box2) texture bfs bfd spriteTexUniform spriteProgram =
  
negative.code:             let cpuOffset = cpuOffset + vertexSize
              let position3Unrotated = v2 position.X (position.Y + size.Y)
              let position3 = (position3Unrotated - center).Rotate rotation
              let mutable vertex3 = Unchecked.defaultof<SpriteBatchVertex>
              vertex3.SbvPosition <- position3
              vertex3.SbvCoord <- coords.TopLeft
              vertex3.SbvColor <- color
  