Adding collision to maze walls

Ensure that the Player object is positioned in the center of cell of the grid. e.g. calculate a random position for the player:

def load_player(background):
    pimg = pygame.Surface((10, 10))
    pimg.fill((200, 20, 20))
    
    px = random.randint(0, rows-1) * width + width//2
    py = random.randint(0, cols-1) * width + width//2
    return Player(pimg, (px, py), background)

To track the player, but highlight the player position, the current player position has to be tint in a different color, before the player is updated and is redrawn:

pygame.draw.rect(screen, (255, 164, 164), player.rect)
sprites.update(None, dt)
sprites.draw(screen)

For the collision test:

• The current position of the player in the grid has to be identified.
• The new possible new position of the player, dependent on the movement has to be identified.
• If a wall is on the track from the current to the new position, then the movement has to be skipped

class Player(pygame.sprite.Sprite):
    def __init__(self, image, pos, background):
        super().__init__()
        self.image = image
        self.pos = pygame.Vector2(pos)
        self.rect = self.image.get_rect(center=self.pos)
        self.background = background

    def update(self, events, dt):
        pressed = pygame.key.get_pressed()
        move = pygame.Vector2((0, 0))

        # calculate maximum movement and current cell position  
        testdist = dt // 5 + 2
        cellx = self.rect.centerx // width
        celly = self.rect.centery // width
        minx = self.rect.left // width
        maxx = self.rect.right // width
        miny = self.rect.top // width
        maxy = self.rect.bottom // width
        
        # test move up
        if minx == maxx and pressed[pygame.K_w]:
            nexty = (self.rect.top-testdist) // width
            if celly == nexty or (nexty >= 0 and not grid[celly][cellx].walls[0]):
                move += (0, -1)

        # test move right
        elif miny == maxy and pressed[pygame.K_d]:
            nextx = (self.rect.right+testdist) // width
            if cellx == nextx or (nextx < cols and not grid[celly][cellx].walls[1]):
                move += (1, 0)
               
        # test move down
        elif minx == maxx and pressed[pygame.K_s]:
            nexty = (self.rect.bottom+testdist) // width
            if celly == nexty or (nexty < rows and not grid[celly][cellx].walls[2]):
                move += (0, 1)            

        # test move left
        elif miny == maxy and pressed[pygame.K_a]:
            nextx = (self.rect.left-testdist) // width
            if cellx == nextx or (nextx >= 0 and not grid[celly][cellx].walls[3]):
                move += (-1, 0)
        
        self.pos = self.pos + move*(dt/5)
        self.rect.center = self.pos        

---

If you want to restart the maze, the you’ve to get rid of the nested game loops. Use 1 game loop and a condition, which state if the game is in play state or initializing the maze.

To check if the player has reached the goal can be done by pygame.Rect.colliderect():

finished = pygame.Rect(0, 0, width, width).colliderect(player.rect)

To restart you’ve to reset the grid:

grid = []
for y in range(rows):
    grid.append([])
    for x in range(cols):
        grid[y].append(Cell(x,y))
current_cell = grid[0][0]

Set the player to a new random position:

px = random.randint(0, rows-1) * width + width//2
py = random.randint(0, cols-1) * width + width//2
player.pos = pygame.Vector2(px, py)
player.rect = player.image.get_rect(center=player.pos)

Clear the background and reset the state play:

screen.fill(0)
play = False

Full main code:

def main():
    global current_cell, grid

    player = None
    initialized = False
    current_maze = None
    dt = 0  
    screen_rect = screen.get_rect()
    clock = pygame.time.Clock()
    sprites = pygame.sprite.Group()

    if not initialized:
        #current_maze = 0
        background = load_background()
        background = None
        player = load_player(background)
        sprites.add(player)
        initialized = True

    play = False 
    while not done:
        # --- Main event loop
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                return

        if play == True:
            
            pygame.draw.rect(screen, (255, 164, 164), player.rect)
            sprites.update(None, dt)
            sprites.draw(screen)

            dt = clock.tick(60)

            finished = pygame.Rect(0, 0, width, width).colliderect(player.rect)
            if finished:
                # init new grid
                grid = []
                for y in range(rows):
                    grid.append([])
                    for x in range(cols):
                        grid[y].append(Cell(x,y))
                current_cell = grid[0][0]
                # create new random player positon
                px = random.randint(0, rows-1) * width + width//2
                py = random.randint(0, cols-1) * width + width//2
                player.pos = pygame.Vector2(px, py)
                player.rect = player.image.get_rect(center=player.pos)
                # clear screen
                screen.fill(0)
                play = False

        else:
            current_cell.visited = True
            current_cell.current = True

            next_cell = current_cell.checkNeighbors()
            if next_cell != False:
                current_cell.neighbors = []
                stack.append(current_cell)
                removeWalls(current_cell,next_cell)
                current_cell.current = False
                current_cell = next_cell
            elif len(stack) > 0:
                current_cell.current = False
                current_cell = stack.pop()
            else:
                play = True

            for y in range(rows):
                for x in range(cols):
                    grid[y][x].draw()

        pygame.display.flip()

see also How do I prevent the player from moving through the walls in a maze?