How do I add boundaries to walls?

Question

I am making a game similar to the Binding Of Isaac. I want to have rocks around the screen that block the player's movement.

Where the rock layout is made:

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"              jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj                   ",
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]
rockxcoord = 0
rockycoord = 0
for row in level:
    for col in row:
        if col == "j":
            rock = rocks(rockxcoord, rockycoord)
            rockGroup.add(rock)
        rockxcoord +=32
    rockycoord += 50
    rockxcoord = 0

Where the boundaries are set

    for rock in rockGroup:
        screen.blit(rock.image, [rock.rect.x, rock.rect.y])
        rockCollisionList = pygame.sprite.spritecollide(playerOne, rockGroup, False)
        for rock in rockCollisionList:
            if playerOne.rect.x < rock.rect.x:
                playerOne.rect.x = rock.rect.x - 90
            if playerOne.rect.x > rock.rect.x:
                playerOne.rect.x = rock.rect.x + 80

I have successfully added boundaries on the x axis. However, when doing the same with the y axis it doesn't work properly.

Answer 1

Use PyGame's Sprites. There's a good tutorial on them too. It's a little bit more work initially, but it will save time later. Really, take the time to learn it. It's worth the investment.

Your walls can just be something simple:

class WallSprite( pygame.sprite.Sprite ):
    """ A stationay sprite"""
    def __init__( self, position, image ):
        pygame.sprite.Sprite.__init__( self )
        self.image        = image
        self.rect         = self.image.get_rect()
        self.rect.topleft = position 

    def udpate( self ):
        # does not move
        pass

Create a bunch of walls. Obviously it's more efficient to make a 10 by 1 unit wall as a single sprite, but for the sake of example we will make walls Lego™ style.

# Create 20 randomly-placed walls
wall_image = pygame.image.load("brick_32.png").convert_alpha()
wall_sprites = pygame.sprite.Group()   # a group for all the wall sprites
for i in range(20):
    # create a wall at a random position
    new_wall = WallSprite( ( random.randrange( 0, WINDOW_WIDTH ), random.randrange( 0, WINDOW_HEIGHT ) ), wall_image )
    wall_sprites.add( new_wall )  # put into the sprite group

brick_32.png

In your main loop, the sprite groups can be used for both painting the sprites, and the group collide function to see if your player has hit any wall.

# Main loop
done = False
while not done:

    # Handle user-input
    for event in pygame.event.get():
        if ( event.type == pygame.QUIT ):
            done = True
        # handle direction keys ...

    # move / update the player sprite
    player_sprite.update()

    # handle player <-> wall sprite collisions (for *ALL* walls)
    if ( len( pygame.sprite.spritecollide( player_sprite, wall_sprites, False ) ) > 0 ):
        player_sprite.stop_moving()

    # re-paint the window
    screen.fill( GREEN )
    wall_sprites.draw()   # paints the entire sprite group
    player_sprite.draw()  # paint the player
    pygame.display.flip()

pygame.quit()