render modelViewProj = let
  emptyFB           = FrameBuffer ((colorImage1 (V4 0.5 0.0 0.4 1.0)))
  rasterCtx         = LineCtx 1.0 LastVertex
  fragmentCtx       = accumulationContext (((ColorOp NoBlending (V4 True True True True))))
  vertexShader ((v)) = (PrimMulMatVec (modelViewProj :: Mat 4 4 Float) v, v)
  vertexStream      = fetch "stream4" ((Attribute "position4" :: Vec 4 Float))
  primitiveStream   = mapPrimitives vertexShader vertexStream
  fragmentStream    = rasterizePrimitives rasterCtx ((Flat)) primitiveStream
  fragmentShader    = \((v)) -> ((v))
  frame             = accumulate fragmentCtx fragmentShader fragmentStream emptyFB
 in ScreenOut frame

main = render (Uniform "MVP" :: Mat 4 4 Float)