anchor.diff:              let cpuOffset = cpuOffset + vertexSize
               let position3Unrotated = v2 position.X (position.Y + size.Y)
               let position3 = (position3Unrotated - center).Rotate rotation
  -            let mutable vertex3 = Marshal.PtrToStructure<SpriteBatchVertex> cpuOffset
  +            let mutable vertex3 = Unchecked.defaultof<SpriteBatchVertex>
               vertex3.SbvPosition <- position3
               vertex3.SbvCoord <- coords.TopLeft
               vertex3.SbvColor <- color
  
positive.code:                 else Option.get envOpt // guaranteed to exist
  
              let vertexSize = nativeint sizeof<SpriteBatchVertex>
              let cpuOffset = env.CpuBuffer + vertexSize * nativeint 4
              let position0 = (position - center).Rotate rotation
              let mutable vertex0 = Marshal.PtrToStructure<SpriteBatchVertex> cpuOffset
              vertex0.SbvPosition <- position0
              vertex0.SbvCoord <- coords.BottomLeft
              vertex0.SbvColor <- color
              Marshal.StructureToPtr<SpriteBatchVertex> (vertex0, cpuOffset, false)
  
              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
              vertex1.SbvPosition <- position1
              vertex1.SbvCoord <- coords.BottomRight
              vertex1.SbvColor <- color
  
negative.code:             let cpuOffset = cpuOffset + vertexSize
              let position2Unrotated = v2 (position.X + size.X) (position.Y + size.Y)
              let position2 = (position2Unrotated - center).Rotate rotation
              let mutable vertex2 = Unchecked.defaultof<SpriteBatchVertex>
              vertex2.SbvPosition <- position2
              vertex2.SbvCoord <- coords.TopRight
              vertex2.SbvColor <- color
  