Rotazione -- 90°OPPOSTO

def rotazione_90(pic,canvas):
#@ param pic:picture
#@ param canvas : picture (canvas > pic
  if getWidth(canvas) and getHeight(canvas)<=getWidth(pic) and getHeight(pic):
    return ("il canvas e' troppo piccolo" )

  #pic=makePicture(pickAFile())
  #canvas=makePicture(pickAFile())

  for pic_x in range(0,getWidth(pic)):
    canvas_y=pic_x
    for pic_y in range (0,getHeight(pic)):
      canvas_x=pic_y
      color=getColor(getPixel(pic,pic_x,pic_y))
      setColor(getPixel(canvas,canvas_x,canvas_y),color)
  repaint(canvas)