Funzione scala

#Problema della scala slide4b n60.
#scritto in collaborazione con Matteo Giustini

def scala(pict, startY, w, h, col):
# @param pict: Picture
# @param startY: Int.
## coordinata y del primo scalino
# @param w: Int.
## lunghezza dello scalino
# @param h: Int.
## altezza dello scalino
# @param col: Color
  HEIGHT = getHeight(pict)
  WIDTH = getWidth(pict)
  endX = w
  endY = startY + h
  startX = 0
  scalaX(pict, startY, HEIGHT, WIDTH, w, h, col, endX, startX)
  scalaY(pict, startY, HEIGHT, WIDTH, w, h, col, endY)

def scalaX(pict, startY, HEIGHT, WIDTH, w, h, col, endX, startX):
# disegna le linee orizzontali
# @param endX: Int.
## coordinata x finale dello scalino
# @param startX: Int.
## coordinata x iniziale dello scalino
  for y in range(startY, HEIGHT, h):
    for x in range(min(startX, WIDTH), min(endX, WIDTH)):
      pixel = getPixel(pict, x, y)
      setColor(pixel, col)
    startX = endX
    endX = endX + w


def scalaY(pict, startY, HEIGHT, WIDTH, w, h, col, endY):
# disegna le linee verticali
# @param endY: Int.
## coordinata y finale dello scalino
  for x in range(w, WIDTH, w):
    for y in range(min(startY, HEIGHT), min(endY, HEIGHT)):
      pixel=getPixel(pict, x, y)
      setColor(pixel, col)
    startY = endY
    endY = endY + h