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[PyGame] How to stop the sprite's movement when it touches the edges of the screen? - Printable Version

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How to stop the sprite's movement when it touches the edges of the screen? - mrmn - May-12-2018

I created my first sprite with Pygame and managed to make it move with keyboard keys. However, when it encounters the edges of the screen, it keeps moving beyond them, disappearing from the screen. I would like to make it stop when it touches the edges, how can I do it?

This is my code: https://imgur.com/8N3hUTg


RE: How to stop the sprite's movement when it touches the edges of the screen? - Mark3232 - May-12-2018

Hi

I don't know how to solve your problem, however, it would make it easier for someone to help you if you used " insert python code" .

you can read about it above you post " please make sure to use python tags when inserting code into the forum"

example
"""this is stuff"""
import numpy as np 
data=np.zero((5,5))
....
When it is formatted like this it so much easier to work with. Just copy and paste. This way we can play around with your code and see if we can get it to work. However, I am lazy, so I don't want to manually write it into my editor :P

BR Mark


RE: How to stop the sprite's movement when it touches the edges of the screen? - mrmn - May-12-2018

(May-12-2018, 10:56 AM)Mark3232 Wrote: Hi

I don't know how to solve your problem, however, it would make it easier for someone to help you if you used " insert python code" .

you can read about it above you post " please make sure to use python tags when inserting code into the forum"

example
"""this is stuff"""
import numpy as np 
data=np.zero((5,5))
....
When it is formatted like this it so much easier to work with. Just copy and paste. This way we can play around with your code and see if we can get it to work. However, I am lazy, so I don't want to manually write it into my editor :P

BR Mark


Ok. Here's the code:

import pygame
from pygame import *
import sys

WIDTH = 600
HEIGHT = 480
FPS = 60

# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)

class Player(pygame.sprite.Sprite):
    # sprite for the player
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((50, 50))
        self.image.fill(GREEN)
        self.rect = self.image.get_rect()
        self.rect.center = (WIDTH / 2, HEIGHT / 2)

# initialize pygame and create window
pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("My game")
clock = pygame.time.Clock()
pygame.key.set_repeat(True)

all_sprites = pygame.sprite.Group()
player = Player()
all_sprites.add(player)

# Game loop
while True:
    # keep loop running at the right speed
    clock.tick(FPS)
    # Process input (events)
    for event in pygame.event.get():
        # check for closing window
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        # Moving sprites with arrow keys or WASD
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP or event.key == K_w:
                player.rect.centery -= 5
            elif event.key == pygame.K_DOWN or event.key == K_s:
                player.rect.centery += 5
            elif event.key == pygame.K_LEFT or event.key == K_a:
                player.rect.left -= 5
            elif event.key == pygame.K_RIGHT or event.key == K_d:
                player.rect.right += 5

    # Update
    all_sprites.update()

    # Draw / render
    screen.fill(BLACK)
    all_sprites.draw(screen)
    # *after* drawing everything, flip the display
    pygame.display.flip()



RE: How to stop the sprite's movement when it touches the edges of the screen? - metulburr - May-12-2018

the simple method would be to clamp it in place of the entire screen.

In your player class if you add an update method and in it
self.rect.clamp_ip(screen.get_rect())
where self.rect is the rect of the player and screen.get_rect() is the screen from display and returns a rect of the screen size. But obviously you would want to pre determine the screen size and set it to that, not do it every frame.

and example would be here of similar task
https://python-forum.io/Thread-PyGame-Basic-event-handling-part-3
The 5th code box from the top


RE: How to stop the sprite's movement when it touches the edges of the screen? - Raures - May-13-2018

I'd do it this way, check if player's sprite x axis position + player's sprite width is lower than screen width, if it is, then move sprite to the right.
Example in your code:

import pygame
from pygame import *
import sys
 
WIDTH = 600
HEIGHT = 480
FPS = 60
 
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
 
class Player(pygame.sprite.Sprite):
    # sprite for the player
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((50, 50))
        self.image.fill(GREEN)
        self.rect = self.image.get_rect()
        self.rect.center = (WIDTH / 2, HEIGHT / 2)
 
# initialize pygame and create window
pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("My game")
clock = pygame.time.Clock()
pygame.key.set_repeat(True)
 
all_sprites = pygame.sprite.Group()
player = Player()
all_sprites.add(player)
 
# Game loop
while True:
    # keep loop running at the right speed
    clock.tick(FPS)
    # Process input (events)
    for event in pygame.event.get():
        # check for closing window
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        # Moving sprites with arrow keys or WASD
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP or event.key == K_w:
                player.rect.centery -= 5
            elif event.key == pygame.K_DOWN or event.key == K_s:
                player.rect.centery += 5
            elif event.key == pygame.K_LEFT or event.key == K_a:
                player.rect.left -= 5
            elif event.key == pygame.K_RIGHT or event.key == K_d:
                # basically, if (sprite.x + sprite.width < screen.width): sprite.x += 5
                if player.rect.x + player.imange.get_width() < WIDTH:
                    # not sure if methods are correct
                    player.rect.right += 5
 
    # Update
    all_sprites.update()
 
    # Draw / render
    screen.fill(BLACK)
    all_sprites.draw(screen)
    # *after* drawing everything, flip the display
    pygame.display.flip()



RE: How to stop the sprite's movement when it touches the edges of the screen? - mrmn - May-13-2018

(May-13-2018, 03:31 PM)Raures Wrote: I'd do it this way, check if player's sprite x axis position + player's sprite width is lower than screen width, if it is, then move sprite to the right.
Example in your code:

import pygame
from pygame import *
import sys
 
WIDTH = 600
HEIGHT = 480
FPS = 60
 
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
 
class Player(pygame.sprite.Sprite):
    # sprite for the player
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((50, 50))
        self.image.fill(GREEN)
        self.rect = self.image.get_rect()
        self.rect.center = (WIDTH / 2, HEIGHT / 2)
 
# initialize pygame and create window
pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("My game")
clock = pygame.time.Clock()
pygame.key.set_repeat(True)
 
all_sprites = pygame.sprite.Group()
player = Player()
all_sprites.add(player)
 
# Game loop
while True:
    # keep loop running at the right speed
    clock.tick(FPS)
    # Process input (events)
    for event in pygame.event.get():
        # check for closing window
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        # Moving sprites with arrow keys or WASD
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP or event.key == K_w:
                player.rect.centery -= 5
            elif event.key == pygame.K_DOWN or event.key == K_s:
                player.rect.centery += 5
            elif event.key == pygame.K_LEFT or event.key == K_a:
                player.rect.left -= 5
            elif event.key == pygame.K_RIGHT or event.key == K_d:
                # basically, if (sprite.x + sprite.width < screen.width): sprite.x += 5
                if player.rect.x + player.imange.get_width() < WIDTH:
                    # not sure if methods are correct
                    player.rect.right += 5
 
    # Update
    all_sprites.update()
 
    # Draw / render
    screen.fill(BLACK)
    all_sprites.draw(screen)
    # *after* drawing everything, flip the display
    pygame.display.flip()

I tried it, but this way the sprite only moves upward-right, stops only at the right edge and refuses to move leftward