In PyGame, basic collision detection can be done using pygame.Rect objects. The Rect
object offers various methods for detecting collisions between objects. Note that even the collision of a rectangular object with a circular object such as a paddle and a ball in Pong game can be roughly detected by a collision between two rectangular objects, the paddle and the bounding rectangle of the ball.
Some examples:
pygame.Rect.collidepoint:
Test if a point is inside a rectangle
repl.it/@Rabbid76/PyGame-collidepoint
import pygame
pygame.init()
window = pygame.display.set_mode((250, 250))
rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(100, 100)
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
point = pygame.mouse.get_pos()
collide = rect.collidepoint(point)
color = (255, 0, 0) if collide else (255, 255, 255)
window.fill(0)
pygame.draw.rect(window, color, rect)
pygame.display.flip()
pygame.quit()
exit()
pygame.Rect.colliderect
Test if two rectangles overlap
See also How to detect collisions between two rectangular objects or images in pygame
repl.it/@Rabbid76/PyGame-colliderect
import pygame
pygame.init()
window = pygame.display.set_mode((250, 250))
rect1 = pygame.Rect(*window.get_rect().center, 0, 0).inflate(75, 75)
rect2 = pygame.Rect(0, 0, 75, 75)
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
rect2.center = pygame.mouse.get_pos()
collide = rect1.colliderect(rect2)
color = (255, 0, 0) if collide else (255, 255, 255)
window.fill(0)
pygame.draw.rect(window, color, rect1)
pygame.draw.rect(window, (0, 255, 0), rect2, 6, 1)
pygame.display.flip()
pygame.quit()
exit()
Furthermore pygame.Rect.collidelist and pygame.Rect.collidelistall can be used for the collision test between a rectangle and a list of rectangles. pygame.Rect.collidedict and pygame.Rect.collidedictall can be used for the collision collision test between a rectangle and a dictionary of rectangles.
The collision of pygame.sprite.Sprite and pygame.sprite.Group objects, can be detected by pygame.sprite.spritecollide(), pygame.sprite.groupcollide() or pygame.sprite.spritecollideany(). When using these methods, the collision detection algorithm can be specified by the collided
argument:
The collided argument is a callback function used to calculate if two sprites are colliding.
Possible collided
callables are collide_rect, collide_rect_ratio, collide_circle, collide_circle_ratio, collide_mask
Some examples:
pygame.sprite.spritecollide()
repl.it/@Rabbid76/PyGame-spritecollide
import pygame
pygame.init()
window = pygame.display.set_mode((250, 250))
sprite1 = pygame.sprite.Sprite()
sprite1.image = pygame.Surface((75, 75))
sprite1.image.fill((255, 0, 0))
sprite1.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(75, 75)
sprite2 = pygame.sprite.Sprite()
sprite2.image = pygame.Surface((75, 75))
sprite2.image.fill((0, 255, 0))
sprite2.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(75, 75)
all_group = pygame.sprite.Group([sprite2, sprite1])
test_group = pygame.sprite.Group(sprite2)
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
sprite1.rect.center = pygame.mouse.get_pos()
collide = pygame.sprite.spritecollide(sprite1, test_group, False)
window.fill(0)
all_group.draw(window)
for s in collide:
pygame.draw.rect(window, (255, 255, 255), s.rect, 5, 1)
pygame.display.flip()
pygame.quit()
exit()
For a collision with masks see How can I made a collision mask? or Pygame mask collision
See also Collision and Intersection
pygame.sprite.spritecollide() / collide_circle
repl.it/@Rabbid76/PyGame-spritecollidecollidecircle
import pygame
pygame.init()
window = pygame.display.set_mode((250, 250))
sprite1 = pygame.sprite.Sprite()
sprite1.image = pygame.Surface((80, 80), pygame.SRCALPHA)
pygame.draw.circle(sprite1.image, (255, 0, 0), (40, 40), 40)
sprite1.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(40, 40)
sprite2 = pygame.sprite.Sprite()
sprite2.image = pygame.Surface((80, 89), pygame.SRCALPHA)
pygame.draw.circle(sprite2.image, (0, 255, 0), (40, 40), 40)
sprite2.rect = pygame.Rect(*window.get_rect().center, 0, 0).inflate(80, 80)
all_group = pygame.sprite.Group([sprite2, sprite1])
test_group = pygame.sprite.Group(sprite2)
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
sprite1.rect.center = pygame.mouse.get_pos()
collide = pygame.sprite.spritecollide(sprite1, test_group, False, pygame.sprite.collide_circle)
window.fill(0)
all_group.draw(window)
for s in collide:
pygame.draw.circle(window, (255, 255, 255), s.rect.center, s.rect.width // 2, 5)
pygame.display.flip()
pygame.quit()
exit()