-> Double -> Double -> C.Surface -> C.Render ()
renderSurface x y alpha surface = do
  C.save
  C.setSourceSurface surface x y
  C.paintWithAlpha alpha
  C.restore

pngSurfaceSize :: File
renderSurface :: Double -> Double -> Double -> C.Surface -> C.Render ()
renderSurface x y alpha surface = do
  C.save
  C.setSourceSurface surface x y
  C.paintWithAlpha alpha
  C.restore
renderSurface x y alpha surface = do
  C.save
  C.setSourceSurface surface x y
  C.paintWithAlpha alpha
  C.restore