pygame moving rectangles | Not updating

Question

My idea was to safe the rectangles in world[] to then move them every game tick to the left by using: velocity_map. The class World is only for creating the pattern of rectangles, that are supposed to move. I want this pattern of rectangles to move to the left, but instead of moving them, a lot of new ones, will be created wihle moving to the left, but the old ones are not beeing removed by the pygame.display.update() function. How do I move the them correctly?

import sys
import pygame


class World():
    def setupMap(data):
        tile_list = []

        row_count = 0
        for row in data:
            col_count = 0
            for tile in row:
                if tile == 1:
                    barrier_surface = pygame.Surface([80, 80])
                    barrier_surface.fill([0, 0, 0])
                    barrier_rect = barrier_surface.get_rect()
                    barrier_rect.x = col_count * tile_size
                    barrier_rect.y = row_count * tile_size
                    tile = barrier_surface, barrier_rect
                    tile_list.append(tile)
                if tile == 2:
                    barrier_surface = pygame.Surface([80, 80])
                    barrier_surface.fill([255, 0, 0])
                    barrier_rect = barrier_surface.get_rect()
                    barrier_rect.x = col_count * tile_size
                    barrier_rect.y = row_count * tile_size
                    tile = barrier_surface, barrier_rect
                    tile_list.append(tile)
                col_count += 1
            row_count += 1
        return tile_list


def draw(tile_list):
    for tile in tile_list:
        screen.blit(tile[0], tile[1])


def move(tile_list):
    for h in tile_list:
        h[1].centerx -= velocity_map
    return tile_list


def draw_grid():
    for line in range(0, 20):
        pygame.draw.line(screen, (0, 0, 0), (0, line * tile_size), (1280, line * tile_size))
        pygame.draw.line(screen, (0, 0, 0), (line * tile_size, 0), (line * tile_size, 640))


def drawBlocks(tile):
    for h in tile:
        screen.blit(h[0], h[1])


# Window settings
pygame.init()
screen = pygame.display.set_mode((1280, 640), 0, 32)
screen.fill([255, 255, 255])
pygame.display.set_caption("Geometrydash")

# Game Variables
tile_size = 80
velocity_map = 1

# Map 1= Block 2= Spike
world_data = [
    [0, 0, 0, 1],
    [0, 0, 0, 0],
    [0, 1, 1, 0],
    [0, 0, 0, 0],
    [0, 1, 1, 0],
    [0, 0, 0, 0],
    [0, 1, 1, 0],
    [0, 0, 2, 0],
]

# Welt klasse laden
world = World.setupMap(world_data)

# Clock
clock = pygame.time.Clock()

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

    world = move(world)
    draw(world)

    draw_grid()
    clock.tick(60)

score 1 · Answer 1 · answered May 18 '21 at 00:40

Before you draw new information to the screen you want to clear it.

to do this you want to do

screen.fill((0,0,0))

another problem i see is that you are drawing to the screen in a function that you never passed screen too, what you might want to do is have a new variable in the draw function for screen so

def draw(screen,draw_list):
  #draw code

draw(screen, world)

score 1 · Accepted Answer · answered May 18 '21 at 03:57

You have to clear the display in every frame with pygame.Surface.fill:

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

    world = move(world)
    
    screen.fill([255, 255, 255])
    draw(world)
    draw_grid()
    pygame.display.update()

    clock.tick(60)

The typical PyGame application loop has to:

handle the events by either pygame.event.pump() or pygame.event.get().
update the game states and positions of objects dependent on the input events and time (respectively frames)
clear the entire display or draw the background
draw the entire scene (blit all the objects)
update the display by either pygame.display.update() or pygame.display.flip()
limit frames per second to limit CPU usage

pygame moving rectangles | Not updating

2 Answers2