Create Expanding Ripple Effects with Pygame: A Step-by-Step Guide

When the mouse is clicked, a circle expands outward from the cursor like a ripple, with random size and color, stopping after reaching a random radius.

Example screenshots of the effect:

The implementation uses Pygame. The script initializes a 600×400 window, maintains up to ten circles, and on each mouse click creates a new circle with a random RGB color and radius growth. The main loop updates radii, draws circles, and removes them once they exceed a random maximum size.

import pygame, random, sys, time
pygame.init()
screen = pygame.display.set_mode([600, 400])
screen.fill((255, 255, 255))
radiusr = 0
arrradiusr = [0] * 10  # circle radii
arraddradiusr = [0] * 10  # radius increments
arrradiusbool = [False] * 10  # existence flag
arrradiusx = [0] * 10  # x positions
arrradiusy = [0] * 10  # y positions
RGBx = [0] * 10
RGBy = [0] * 10
RGBz = [0] * 10

while True:
    time.sleep(0.1)
    for event in pygame.event.get():
        if event.type == pygame.MOUSEBUTTONDOWN:
            num = arrradiusbool.index(False)
            arrradiusbool[num] = True
            arrradiusr[num] = 0
            arrradiusx[num], arrradiusy[num] = pygame.mouse.get_pos()
            RGBx[num] = random.randint(0, 255)
            RGBy[num] = random.randint(0, 255)
            RGBz[num] = random.randint(0, 255)
            pygame.draw.circle(screen, pygame.Color(RGBx[num], RGBy[num], RGBz[num]),
                               (arrradiusx[num], arrradiusy[num]), arrradiusr[num], 1)
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
    for i in range(10):
        if not arrradiusbool[i]:
            continue
        if arrradiusr[i] < random.randint(10, 50):
            arraddradiusr[i] = random.randint(0, 5)
            arrradiusr[i] += arraddradiusr[i]
            pygame.draw.circle(screen, pygame.Color(RGBx[i], RGBy[i], RGBz[i]),
                               (arrradiusx[i], arrradiusy[i]), arrradiusr[i], 1)
        else:
            arrradiusbool[i] = False
    pygame.display.update()