Why is my collision test always returning 'true' and why is the position of the rectangle of the image always wrong (0, 0)?

Question

My collide_rect function isn't working properly. It always returns True, when it's not suppose to. I have tried looking on the internet but nothing is working for me. I think the collide rect somehow did not use the actual coordinates for the two sprites. Can anyone help with this?

import pygame import pygame.sprite import sys gameDisplay = pygame.display.set_mode((800,600)) pygame.display.set_caption("test_collision") clock = pygame.time.Clock() crashed = False class Ball(pygame.sprite.Sprite): def __init__(self): pygame.sprite.Sprite.__init__(self) self.image = pygame.image.load("ball.png") self.rect = self.image.get_rect() self.x = 280 self.y = 475 self.col = False def update(self): gameDisplay.blit(self.image, (self.x,self.y)) self.rect = self.image.get_rect() def test_collisions(self,sprite): self.col = pygame.sprite.collide_rect(self,sprite) class Obstacle(pygame.sprite.Sprite): def __init__(self): pygame.sprite.Sprite.__init__(self) self.x = 1000 self.y = 483 self.image = pygame.image.load("obstacle.png") self.time = pygame.time.get_ticks() self.rect = self.image.get_rect() def change_x(self): self.time = pygame.time.get_ticks() self.x = -(self.time/5) + 800 def update(self): self.rect = self.image.get_rect() gameDisplay.blit(self.image,(self.x,self.y)) obstacle = Obstacle() ball = Ball() while not crashed: for event in pygame.event.get(): if event.type == pygame.QUIT: crashed = True gameDisplay.fill((255,255,255)) ball.update() obstacle.change_x() obstacle.update() ball.test_collisions(obstacle) if ball.col: print("colided") pygame.display.flip() clock.tick(1000) pygame.quit() sys.exit()

P.S This is my first post :)

Rabbid76 · Accepted Answer · 2021-01-19 14:47:23Z

pygame.Surface.get_rect.get_rect() returns a rectangle with the size of the Surface object, but it returns a rectangle that always starts at (0, 0) since a Surface object has no position.
The Surface is placed at a position on the display with the blit function.

You've to set the location of the rectangle, either by a keyword argument, e.g:

self.rect = self.image.get_rect(topleft = (self.x, self.y))

or an assignment to a virtual attribute (see pygame.Rect), e.g:

self.rect = self.image.get_rect() self.rect.topleft = (self.x, self.y)

It is absolutely unnecessary to add some extra attributes self.x and self.y. Use the location of the rectangle instead. e.g:

class Ball(pygame.sprite.Sprite): def __init__(self): pygame.sprite.Sprite.__init__(self) self.image = pygame.image.load("ball.png") self.rect = self.image.get_rect(topleft = (280, 475)) self.col = False def update(self): gameDisplay.blit(self.image, self.rect) def test_collisions(self,sprite): self.col = pygame.sprite.collide_rect(self,sprite) class Obstacle(pygame.sprite.Sprite): def __init__(self): pygame.sprite.Sprite.__init__(self) self.image = pygame.image.load("obstacle.png") self.time = pygame.time.get_ticks() self.rect = self.image.get_rect(topleft = (1000, 483)) def change_x(self): self.time = pygame.time.get_ticks() self.rect.x = -(self.time/5) + 800 def update(self): gameDisplay.blit(self.image, self.rect)

Further note, that you can get rid of the methods Ball.update() respectively Obstacle.update() (you can delete them), if you use a pygame.sprite.Group and call .draw(), which uses the .image and .rect properties of the contained sprites, to draw them. e.g.:

obstacle = Obstacle() ball = Ball() all_sprites = pygame.sprite.Group([obstacle, ball]) while not crashed: # [...] gameDisplay.fill((255,255,255)) all_sprites.draw(gameDisplay) pygame.display.flip() clock.tick(1000)

Collectives™ on Stack Overflow

Why is my collision test always returning 'true' and why is the position of the rectangle of the image always wrong (0, 0)?

1 Answer 1

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Linked

Related