# This is a combination of Listings 6.1, 6.3, and 6.5
# from Python Programming in Context by Miller and Ranum,
# together with a procedure for showing an image in a window.

from cImage import *

def negativePixel(oldPixel):
    newred = 255 - oldPixel.getRed()
    newgreen = 255 - oldPixel.getGreen()
    newblue = 255 - oldPixel.getBlue()
    newPixel = Pixel(newred, newgreen, newblue)
    return newPixel

def grayPixel(oldpixel):
    intensitySum = oldpixel.getRed() + oldpixel.getGreen() + \
                   oldpixel.getBlue()
    aveRGB = intensitySum // 3

    newPixel = Pixel(aveRGB,aveRGB,aveRGB)
    return newPixel

def pixelMapper(oldimage,rgbFunction):

    width = oldimage.getWidth()          
    height = oldimage.getHeight()
    newim = EmptyImage(width,height)     

    for row in range(height):
        for col in range(width):
            originalPixel = oldimage.getPixel(col,row)
            newPixel = rgbFunction(originalPixel)          
            newim.setPixel(col,row,newPixel)
            
    return newim

def show(image):
    win = ImageWin('Image', image.getWidth(), image.getHeight())
    image.draw(win)
    win.exitOnClick()