drawWidths :: Context -> CFloat -> CFloat -> CFloat -> IO ()
drawWidths c x y width =
  do save c
     strokeColor c (rgba 0 0 0 255)
     forM_ [0..19] $ \i ->
       do let w = (i+0.5)*0.1
              y' = y + (10*i)
          strokeWidth c w
          beginPath c
          moveTo c x y'
          lineTo c (x+width) (y'+width*0.3)
          stroke c
     restore c
drawWidths :: Context -> CFloat -> CFloat -> CFloat -> IO ()
drawWidths c x y width =
  do save c
     strokeColor c (rgba 0 0 0 255)
     forM_ [0..19] $ \i ->
       do let w = (i+0.5)*0.1
              y' = y + (10*i)
          strokeWidth c w
          beginPath c
          moveTo c x y'
          lineTo c (x+width) (y'+width*0.3)
          stroke c
     restore c
drawWidths c x y width =
  do save c
     strokeColor c (rgba 0 0 0 255)
     forM_ [0..19] $ \i ->
       do let w = (i+0.5)*0.1
              y' = y + (10*i)
          strokeWidth c w
          beginPath c
          moveTo c x y'
          lineTo c (x+width) (y'+width*0.3)
          stroke c
     restore c