PyGame Collisions does only work on one side of the rectangle

Question

I'm just trying something with collisions and found the way to check one side of the rectangle with the other side.

I have the following problem:

If I move my game character (pink box) from the left against the object, my game character just moves through it:

If I come from the other side, everything works and my game character stops.

I mean to say that I need the same code for both sides but have to change the sides from if not player_rect.left == other_rect.right: to if not player_rect.right == other_rect.left:. But this does not work for one side.

import pygame
import sys

pygame.init()

clock = pygame.time.Clock()
window = pygame.display.set_mode([1200, 800])
pygame.display.set_caption("Collision Test")

x = 300
y = 300
width = 48
height = 96
velocity = 5

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        is_pressed = pygame.key.get_pressed()
        player_rect = pygame.Rect(x, y, width, height)
        other_rect = pygame.Rect(400, 300, 50, 50)

        if is_pressed[pygame.K_d]:
            if not player_rect.right == other_rect.left:
                x += velocity
        if is_pressed[pygame.K_a]:
            if not player_rect.left == other_rect.right:
                x -= velocity

    window.fill((100, 150, 50))
    pygame.draw.rect(window, (255, 50, 100), player_rect)
    pygame.draw.rect(window, (255, 100, 50), other_rect)
    pygame.display.update()
    clock.tick(60)

score 1 · Accepted Answer · answered Oct 20 '20 at 10:59

Use collideRect().

Move the object and test if the rectangles are colliding. When a collision is detected, change the position of the object according to the moving direction:

is_pressed = pygame.key.get_pressed()
move_right = is_pressed[pygame.K_d]
move_left = is_pressed[pygame.K_a]

if move_right:
    x += velocity
if move_left:
    x -= velocity

player_rect = pygame.Rect(x, y, width, height)
other_rect = pygame.Rect(400, 300, 50, 50)

if player_rect.colliderect(other_rect):
    if move_right:
        player_rect.right = other_rect.left
        x = player_rect.left
    if move_left:
        player_rect.left = other_rect.right
        x = player_rect.left

For a smooth movement you've to do evaluate pygame.key.get_pressed() in the application loop rather than the event loop.
See also What all things happens inside pygame when I press a key? When to use pygame.event==KEYDOWN.

import pygame
import sys

pygame.init()

clock = pygame.time.Clock()
window = pygame.display.set_mode([1200, 800])
pygame.display.set_caption("Collision Test")

x = 300
y = 300
width = 48
height = 96
velocity = 5

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

    is_pressed = pygame.key.get_pressed()
    move_right = is_pressed[pygame.K_d]
    move_left = is_pressed[pygame.K_a]

    if move_right:
        x += velocity
    if move_left:
        x -= velocity

    player_rect = pygame.Rect(x, y, width, height)
    other_rect = pygame.Rect(400, 300, 50, 50)

    if player_rect.colliderect(other_rect):
        if move_right:
            player_rect.right = other_rect.left
            x = player_rect.left
        if move_left:
            player_rect.left = other_rect.right
            x = player_rect.left

    window.fill((100, 150, 50))
    pygame.draw.rect(window, (255, 50, 100), player_rect)
    pygame.draw.rect(window, (255, 100, 50), other_rect)
    pygame.display.update()
    clock.tick(60)

Now how do I implement a jump or gravity.Of course this should work with the collisions above and below. I have already tried a lot of things, but I can't find a solution. I had added a jump but then I was on the rectangle and when I tried to run down it, I didn't fall down anymore. Please help me — Max, Oct 20 '20 at 13:22
@Max If you have a new question, please [Ask a public question](https://stackoverflow.com/questions/ask). The comments section is not intended to be used to ask additional questions. Don't extend this question either, you'll have to ask a completely new question. Please share in the new question what you have tried so far. — Rabbid76, Oct 20 '20 at 13:25
Okay, sorry. But it says i need to wait 2 more days to ask a new Question. — Max, Oct 20 '20 at 13:32
@Max Are you sure about that. Do you have to wait at all even though this question was upvoted and has an accepted answer? — Rabbid76, Oct 20 '20 at 13:37
"You have reached your question limit It looks like you might need a break - take a breather and come back soon! You've asked 2 questions recently, some of which have not been received very well by the..." It seems like it :/ — Max, Oct 20 '20 at 13:45

PyGame Collisions does only work on one side of the rectangle

1 Answers1