# follow_mouse.py  -- by leonardo maffi, V.1.1, July 26 2006.
# Converted to Python from this Processing (Java) program:
# http://www.processing.org/learning/examples/storinginput.html

import pygame # http://www.pygame.org/download.shtml

def follow_mouse(nx=640, ny=480, num=60):
    pygame.init()
    screen = pygame.display.set_mode((nx, ny), 0, 8) #greyscale screen!
    pygame.display.set_palette( [(i,i,i) for i in xrange(256)] ) #greyscale screen!
    pygame.display.set_caption("Follow mouse")

    last = 0
    a = [pygame.mouse.get_pos() for i in xrange(num)]

    while True:
        for ev in pygame.event.get():
            if ev.type == pygame.QUIT:
                return

        last = (last + 1) % num
        a[last] = pygame.mouse.get_pos()
        screen.fill(0, (0, 0, nx-1, ny-1))

        for r in xrange(num):
            pos = a[(last + 1 + r) % num]
            # circle parameters: Surface, color, pos, radius, width
            pygame.draw.circle(screen, r*2+(255-num-num), pos, r/2, 0)

        pygame.display.flip()
        #pygame.time.wait(10)

follow_mouse(nx=300, ny=300)