收集金币

本课属于 Coddy Pygame 学习旅程的“游戏世界”单元。第 31 课，共 36 课。

金币能给探险者一个前进的目标：有几枚金币悬在坑上方，想要拿到它们就得冒险。

把每个 C 都读入一个 Rect 列表，范围覆盖整个瓦片，因为 coin.png 自带空白边框。玩家碰到金币时，把它从列表中移除并计数：

for coin in coins[:]:
    if player.colliderect(coin):
        coins.remove(coin)
        coins_collected += 1

coins[:] 是列表的副本。在循环遍历列表时移除其中的项，会让后续项在循环中移动并跳过一项；遍历副本就能避免这个问题。

在右上角显示计数。计数属于窗口，而不是关卡，因此绘制时不使用摄像机：

font = pygame.font.Font("assets/fonts/pixel.ttf", 24)
# 在循环中
text = font.render(f"Coins: {coins_collected}", True, (255, 255, 255))
screen.blit(text, text.get_rect(topright=(WIDTH - 12, 14)))

挑战

中等

添加硬币以收集。

将 coin.png 加载到 coin_img；创建 font（assets/fonts/pixel.ttf，大小为 24）、coins = [] 和 coins_collected = 0。
每个 C 都会将其图块 Rect 添加到 coins。
移动后，移除每个碰到的硬币，并将 coins_collected 加 1。
通过摄像机绘制硬币，并按图示在右上角显示 Coins: 0。

按“开始”并捡起一枚硬币：计数会增加。然后按“检查”。

亲手试试

import pygame

TILE = 36
WIDTH, HEIGHT = 576, 360
SPEED = 4
GRAVITY = 1
JUMP = -15
MAX_FALL = 12

LEVEL = [
    "................................................................",
    "................................................................",
    "................................................................",
    "................................................................",
    "#..............................................................#",
    "#....................C.........................#####...........#",
    "#......CC...C................CC.....CC.........#####.....CC....#",
    "#....................#.........................D...............#",
    "#.P.........#...E....#...^.......K......E......D.C....^......F.#",
    "#######..####################..##########################..#####",
]

pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Moss Caves")
clock = pygame.time.Clock()


def load(name):
    return pygame.image.load("assets/images/" + name).convert_alpha()


background = pygame.image.load("assets/backgrounds/forest.png").convert_alpha()
grass_img = load("grass.png")
grass_left_img = load("grass_left.png")
grass_right_img = load("grass_right.png")
dirt_img = load("dirt.png")
player_img = load("player.png")


def solid(row, col):
    if row < 0 or row >= len(LEVEL) or col < 0 or col >= len(LEVEL[0]):
        return False
    return LEVEL[row][col] == "#"


walls = []
tiles = []
for row, line in enumerate(LEVEL):
    for col, char in enumerate(line):
        rect = pygame.Rect(col * TILE, row * TILE, TILE, TILE)
        if char == "#":
            if solid(row - 1, col):
                image = dirt_img
            elif not solid(row, col - 1) and solid(row, col + 1):
                image = grass_left_img
            elif solid(row, col - 1) and not solid(row, col + 1):
                image = grass_right_img
            else:
                image = grass_img
            walls.append(rect)
            tiles.append((image, rect))
        elif char == "P":
            start = rect.midbottom

level_width = len(LEVEL[0]) * TILE
player = player_img.get_rect(midbottom=start)
vel_y = 0
on_ground = False
camera_x = 0

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN and event.key in (pygame.K_SPACE, pygame.K_UP):
            if on_ground:
                vel_y = JUMP
        elif event.type == pygame.KEYUP and event.key in (pygame.K_SPACE, pygame.K_UP):
            if vel_y < -4:
                vel_y = -4

    keys = pygame.key.get_pressed()
    dx = 0
    if keys[pygame.K_LEFT]:
        dx -= SPEED
    if keys[pygame.K_RIGHT]:
        dx += SPEED

    player.x += dx
    for wall in walls:
        if player.colliderect(wall):
            if dx > 0:
                player.right = wall.left
            elif dx < 0:
                player.left = wall.right

    vel_y = min(vel_y + GRAVITY, MAX_FALL)
    player.y += vel_y
    on_ground = False
    for wall in walls:
        if player.colliderect(wall):
            if vel_y > 0:
                player.bottom = wall.top
                on_ground = True
            elif vel_y < 0:
                player.top = wall.bottom
            vel_y = 0

    if player.top > HEIGHT:
        player.midbottom = start
        vel_y = 0

    camera_x = player.centerx - WIDTH // 2
    camera_x = max(0, min(camera_x, level_width - WIDTH))

    shift = camera_x // 3 % 72
    for y in range(0, HEIGHT, 72):
        for x in range(-shift, WIDTH, 72):
            screen.blit(background, (x, y))
    for image, rect in tiles:
        screen.blit(image, (rect.x - camera_x, rect.y))
    screen.blit(player_img, (player.x - camera_x, player.y))
    pygame.display.flip()
    clock.tick(60)

pygame.quit()

游戏世界中的所有课

自己练习： Pygame 在线编辑器