python - 如何防止玩家在pygame的迷宫中穿过墙壁？

Question

我有一个以网格组织的迷宫。网格的每个单元格都存储有关其右侧和底部相邻单元格的墙壁的信息。玩家是一个特定大小的对象，其边界框是已知的。我想让玩家顺利通过迷宫，墙壁阻止他们通过。

最小且可重复的示例：

import pygame, random

class Maze:
    def __init__(self, rows = 9, columns = 9):
        self.size = (columns, rows)
        self.walls = [[[True, True] for _ in range(self.size[1])] for __ in range(self.size[0])]
        visited = [[False for _ in range(self.size[1])] for __ in range(self.size[0])]
        i, j = (self.size[0]+1) // 2, (self.size[1]+1) // 2
        visited[i][j] = True
        stack = [(i, j)]
        while stack:
            current = stack.pop()
            i, j = current
            nl = [n for n in [(i-1, j), (i+1, j), (i, j-1), (i, j+1)] 
                  if 0 <= n[0] < self.size[0] and 0 <= n[1] < self.size[1] and not visited[n[0]][n[1]]]
            if nl:
                stack.insert(0, current)
                next = random.choice(nl)
                self.walls[min(next[0], current[0])][min(next[1], current[1])][abs(next[1]-current[1])] = False
                visited[next[0]][next[1]] = True
                stack.insert(0, next)

def draw_maze(surf, maze, x, y, l, color, width):
    lines = [((x, y), (x + l * len(maze.walls), y)), ((x, y), (x, y + l * len(maze.walls[0])))] 
    for i, row in enumerate(maze.walls):
        for j, cell in enumerate(row):
            if cell[0]: lines += [((x + i*l + l, y + j*l), (x + i*l + l, y + j*l + l))]
            if cell[1]: lines += [((x + i*l, y + j*l + l), (x + i*l + l, y + j*l + l))]
    for line in lines:
        pygame.draw.line(surf, color, *line, width)

pygame.init()
window = pygame.display.set_mode((400, 400))
clock = pygame.time.Clock()

maze = Maze()
player_rect = pygame.Rect(190, 190, 20, 20)

run = True
while run:
    clock.tick(100)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    keys = pygame.key.get_pressed()
    player_rect.x += (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * 3
    player_rect.y += (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * 3

    window.fill(0)
    draw_maze(window, maze, 20, 20, 40, (196, 196, 196), 3)
    pygame.draw.circle(window, (255, 255, 0), player_rect.center, player_rect.width//2)
    pygame.display.flip()

pygame.quit()
exit()

标签： pythonpygamecollision-detectionmaze

Answer 1

使用蒙版碰撞。画一个透明的迷宫pygame.Surface：

cell_size = 40
maze = Maze()
maze_surf = pygame.Surface((maze.size[0]*cell_size, maze.size[1]*cell_size), pygame.SRCALPHA)
draw_maze(maze_surf, maze, 0, 0, cell_size, (196, 196, 196), 3)

使用 以下命令pygame.Mask从Surface创建一个板条箱pygame.mask.from_surface：

maze_mask = pygame.mask.from_surface(maze_surf)

从播放器创建一个蒙版：

player_rect = pygame.Rect(190, 190, 20, 20)
player_surf = pygame.Surface(player_rect.size, pygame.SRCALPHA)
pygame.draw.circle(player_surf, (255, 255, 0), (player_rect.width//2, player_rect.height//2), player_rect.width//2)
player_mask = pygame.mask.from_surface(player_surf)

计算玩家的新位置：

keys = pygame.key.get_pressed()
new_rect = player_rect.move(
    (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * 3,  
    (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * 3)

用于pygame.mask.Mask.overlap查看遮罩是否相交（请参阅Pygame 与遮罩的碰撞不起作用）。当迷宫的面具与玩家的面具相交时跳过移动：

offset = (new_rect.x - maze_pos[0]), (new_rect.y - maze_pos[1])
if not maze_mask.overlap(player_mask, offset):
    player_rect = new_rect

另见迷宫碰撞检测

---

最小的例子： repl.it/@Rabbid76/PyGame-Maze-MaskCollision

import pygame, random

class Maze:
    def __init__(self, rows = 9, columns = 9):
        self.size = (columns, rows)
        self.walls = [[[True, True] for _ in range(self.size[1])] for __ in range(self.size[0])]
        visited = [[False for _ in range(self.size[1])] for __ in range(self.size[0])]
        i, j = (self.size[0]+1) // 2, (self.size[1]+1) // 2
        visited[i][j] = True
        stack = [(i, j)]
        while stack:
            current = stack.pop()
            i, j = current
            nl = [n for n in [(i-1, j), (i+1, j), (i, j-1), (i, j+1)] 
                  if 0 <= n[0] < self.size[0] and 0 <= n[1] < self.size[1] and not visited[n[0]][n[1]]]
            if nl:
                stack.insert(0, current)
                next = random.choice(nl)
                self.walls[min(next[0], current[0])][min(next[1], current[1])][abs(next[1]-current[1])] = False
                visited[next[0]][next[1]] = True
                stack.insert(0, next)

def draw_maze(surf, maze, x, y, l, color, width):
    lines = [((x, y), (x + l * len(maze.walls), y)), ((x, y), (x, y + l * len(maze.walls[0])))] 
    for i, row in enumerate(maze.walls):
        for j, cell in enumerate(row):
            if cell[0]: lines += [((x + i*l + l, y + j*l), (x + i*l + l, y + j*l + l))]
            if cell[1]: lines += [((x + i*l, y + j*l + l), (x + i*l + l, y + j*l + l))]
    for line in lines:
        pygame.draw.line(surf, color, *line, width)

pygame.init()
window = pygame.display.set_mode((400, 400))
clock = pygame.time.Clock()

maze_pos = 20, 20
cell_size = 40
maze = Maze()
maze_surf = pygame.Surface((maze.size[0]*cell_size, maze.size[1]*cell_size), pygame.SRCALPHA)
draw_maze(maze_surf, maze, 0, 0, cell_size, (196, 196, 196), 3)
maze_mask = pygame.mask.from_surface(maze_surf)

player_rect = pygame.Rect(190, 190, 20, 20)
player_surf = pygame.Surface(player_rect.size, pygame.SRCALPHA)
pygame.draw.circle(player_surf, (255, 255, 0), (player_rect.width//2, player_rect.height//2), player_rect.width//2)
player_mask = pygame.mask.from_surface(player_surf)

run = True
while run:
    clock.tick(100)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    keys = pygame.key.get_pressed()
    new_rect = player_rect.move(
        (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * 3,  
        (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * 3)

    offset = (new_rect.x - maze_pos[0]), (new_rect.y - maze_pos[1])
    if not maze_mask.overlap(player_mask, offset):
        player_rect = new_rect

    window.fill(0)
    window.blit(maze_surf, maze_pos)
    window.blit(player_surf, player_rect)
    pygame.display.flip()

pygame.quit()
exit()