anchor.diff:          OpenGL.Hl.Assert ()
   
           // fin
  -        (viewProjectionUniform, perimetersUniform, centersUniform, rotationsUniform, texCoordsesUniform, colorsUniform, texUniform, shader)
  +        (viewProjectionUniform, perimetersUniform, pivotsUniform, rotationsUniform, texCoordsesUniform, colorsUniform, texUniform, shader)
   
       let private BeginBatch state env =
           env.State <- state
  
positive.code:         // grab uniform locations
          let viewProjectionUniform = OpenGL.Gl.GetUniformLocation (shader, "viewProjection")
          let perimetersUniform = OpenGL.Gl.GetUniformLocation (shader, "perimeters")
          let centersUniform = OpenGL.Gl.GetUniformLocation (shader, "centers")
          let rotationsUniform = OpenGL.Gl.GetUniformLocation (shader, "rotations")
          let texCoordsesUniform = OpenGL.Gl.GetUniformLocation (shader, "texCoordses")
          let colorsUniform = OpenGL.Gl.GetUniformLocation (shader, "colors")
  
negative.code:         OpenGL.Hl.Assert (fn ())
          BeginBatch state env
  
      let private PopulateVertex (perimeter : Box2) (pivot : Vector2) (rotation : single) (texCoords : Box2) (color : Color) env =
          let perimeterOffset = env.SpriteIndex * 4
          env.Perimeters.[perimeterOffset] <- perimeter.Position.X
          env.Perimeters.[perimeterOffset + 1] <- perimeter.Position.Y
          env.Perimeters.[perimeterOffset + 2] <- perimeter.Size.X
          env.Perimeters.[perimeterOffset + 3] <- perimeter.Size.Y
          let pivotOffset = env.SpriteIndex * 2
          env.Pivots.[pivotOffset] <- pivot.X
          env.Pivots.[pivotOffset + 1] <- pivot.Y
          let rotationOffset = env.SpriteIndex
          env.Rotations.[rotationOffset] <- rotation
          let texCoordsOffset = env.SpriteIndex * 4
  