BLACK = (0,0,0)

WHITE = (255,255,255)

#

# By given point and square size returns True, if pixel should be black

# or false, if should be white.

#

# Remember, that first square in left bottom corner is black, therefore

# we need to compute it from the start.

#

def isBlackSquare(x, y, squareSize):

     resultX = x / squareSize

     resultY = y / squareSize

return (resultX + resultY) % 2 == 0

#

# Returns distance between two points

#

def getDistance(center, point):

     diffX = center[0] - point[0]

     diffY = center[1] - point[1]

return int(math.sqrt(diffX**2 + diffY**2))

#

# Draws first picture in homework of problem C

#

def drawEffect1(size, squareCount):

     im = Image.new("RGB", (size, size), "white")

     radius = size / 4

     squareSize = size / squareCount

     i = 0

while i < size:

           j = 0

while j < size:

                isBlack = isBlackSquare(i, j, squareSize)

# Getting distance between point and center

                distance = getDistance((size / 2, size / 2), (i,j))

                level = distance / radius

if level % 2 == 1:

if isBlack == True:

                           isBlack = False

else:

                           isBlack = True

if isBlack:

                     im.putpixel((i, size - j - 1), BLACK)

                j += 1

           i += 1

     im.save("effect1.bmp")

#

# If is pixel inside of square in picture, returns True, else returns false.

#

def isInsideSquare(point, squareSize):

     halfSquareSize = squareSize / 2

     startSquareValue = halfSquareSize

     endSquareValue = halfSquareSize * 3

return startSquareValue <= point[0] and startSquareValue <= point[1] and endSquareValue >= point[0] and endSquareValue >= point[1]

#

# Draws second picture in homework of problem C

#

def drawEffect2(size, changeColorCount, squareCount):

     im = Image.new("RGB", (size, size), "white")

     level = size / changeColorCount

     step = 255 / level

# Two because we have square on two sides

     squareSize = size / squareCount

     i = 0

while i < size:

           j = 0

while j < size:

# Getting distance between point and center

                distance = getDistance((size / 2, size / 2), (i,j))

                levelIndex = distance / level

                stepIndex = (distance % level) * step

                isInside = isInsideSquare((i,j), squareSize)

if isInside == False:

                     levelIndex += 2

# If is levelIndex zero, then it has black color

                color = BLACK

# If it has value 1, it is going from dark to white

if levelIndex % 4 == 1:

                     color = (stepIndex, stepIndex, stepIndex)

# If is two, it is white

if levelIndex % 4 == 2:

                     color = WHITE

# And in the end it is going from white to black

if levelIndex % 4 == 3:

                     stepIndex = 255 - stepIndex

                     color = (stepIndex, stepIndex, stepIndex)

                im.putpixel((i,j), color)

                j += 1

           i += 1

     im.save("effect2.bmp")

def isUnderSin(point, halfSize):

     x = point[0]

     y = point[1]

     value = math.sin(math.radians(x)) * halfSize + halfSize

return value < y

def drawEffect3(size, squareCount):

     im = Image.new("RGB", (size, size), "white")

     squareSize = size / squareCount

     halfSize = float(size) / 2

     i = 0

while i < size:

           j = 0

while j < size:

                isBlack = isBlackSquare(i, j, squareSize)

                isUnder = isUnderSin((i, j), halfSize)

if not isUnder:

                     isBlack = not isBlack

if isBlack:

                     im.putpixel((i, size - j - 1), BLACK)

                j += 1

           i += 1

     im.save("effect3.bmp")

from myPixelLib import *

from PIL import Image

import math

drawEffect1(500, 10)

drawEffect2(500, 30, 2)

drawEffect3(500, 10)