pacman.py

"""Pac-Man in Python (pygame). Run: python3 pacman.py"""
import random
import pygame

TILE = 24
ROWS = 21
COLS = 21
FPS = 60
GHOST_SPEED = 2
PAC_SPEED = 3
GHOST_FRIGHT_SPEED = 1

# 1 = wall, . = dot, o = power pellet, ' ' = empty, P = pacman start, G = ghost start
MAZE = [
    "#####################",
    "#.........#.........#",
    "#o###.###.#.###.###o#",
    "#...................#",
    "#.###.#.#####.#.###.#",
    "#.....#...#...#.....#",
    "#####.###.#.###.#####",
    "    #.#.......#.#    ",
    "#####.##.###.##.#####",
    "........#G G#........",
    "#####.##.###.##.#####",
    "    #.#.......#.#    ",
    "#####.##.###.##.#####",
    "#.........#.........#",
    "#.###.###.#.###.###.#",
    "#o..#.....P.....#..o#",
    "###.#.#.#####.#.#.###",
    "#.....#...#...#.....#",
    "#.#######.#.#######.#",
    "#...................#",
    "#####################",
]

BLACK = (0, 0, 0)
BLUE = (33, 33, 222)
YELLOW = (255, 255, 0)
WHITE = (255, 255, 255)
GHOST_COLORS = [(255, 0, 0), (255, 153, 255), (0, 255, 255), (255, 184, 82)]

DIRS = {pygame.K_LEFT: (-1, 0), pygame.K_RIGHT: (1, 0),
        pygame.K_UP: (0, -1), pygame.K_DOWN: (0, 1)}
DIR_NAMES = {(-1, 0): "L", (1, 0): "R", (0, -1): "U", (0, 1): "D"}


def is_wall(col, row):
    if 0 <= row < ROWS and 0 <= col < COLS:
        return MAZE[row][col] == "#"
    return True


def is_playable(col, row):
    if 0 <= row < ROWS and 0 <= col < COLS:
        return MAZE[row][col] != "#"
    return False


class Ghost:
    def __init__(self, col, row, color, name):
        self.start = (col * TILE + TILE // 2, row * TILE + TILE // 2)
        self.color = color
        self.name = name
        self.reset()

    def reset(self):
        self.x, self.y = self.start
        self.dir = random.choice([(-1, 0), (1, 0)])
        self.frightened = False

    def rect(self):
        return pygame.Rect(self.x - TILE // 2 + 2, self.y - TILE // 2 + 2,
                           TILE - 4, TILE - 4)

    def center_tile(self):
        return (int(self.x // TILE), int(self.y // TILE))

    def update(self, pac_tile, dots_left):
        speed = GHOST_FRIGHT_SPEED if self.frightened else GHOST_SPEED

        # Only pick a new direction when aligned with tile center
        cx, cy = self.center_tile()
        tile_center_x = cx * TILE + TILE // 2
        tile_center_y = cy * TILE + TILE // 2
        at_center = abs(self.x - tile_center_x) < speed and abs(self.y - tile_center_y) < speed
        if at_center:
            self.x, self.y = tile_center_x, tile_center_y
            options = []
            for d in DIRS.values():
                nx, ny = cx + d[0], cy + d[1]
                if is_playable(nx, ny):
                    options.append(d)
            # avoid reversing unless dead end
            back = (-self.dir[0], -self.dir[1])
            if back in options and len(options) > 1:
                options.remove(back)
            if options:
                if self.frightened:
                    choice = random.choice(options)
                else:
                    # chase: prefer direction reducing distance to pacman
                    choice = min(
                        options,
                        key=lambda d: (pac_tile[0] - (cx + d[0])) ** 2
                        + (pac_tile[1] - (cy + d[1])) ** 2,
                    )
                self.dir = choice

        self.x += self.dir[0] * speed
        self.y += self.dir[1] * speed


class Game:
    def __init__(self):
        pygame.init()
        self.screen = pygame.display.set_mode((COLS * TILE, ROWS * TILE + 40))
        pygame.display.set_caption("Pac-Man")
        self.clock = pygame.time.Clock()
        self.font = pygame.font.SysFont("arial", 20, bold=True)
        self.big_font = pygame.font.SysFont("arial", 36, bold=True)
        self.reset_level()
        self.score = 0
        self.lives = 3

    def reset_level(self):
        self.dots = set()
        self.pellets = set()
        pac_start = (10 * TILE + TILE // 2, 15 * TILE + TILE // 2)
        for r, line in enumerate(MAZE):
            for c, ch in enumerate(line):
                if ch == ".":
                    self.dots.add((c, r))
                elif ch == "o":
                    self.pellets.add((c, r))
                elif ch == "P":
                    pac_start = (c * TILE + TILE // 2, r * TILE + TILE // 2)
        self.pac = pygame.Rect(pac_start[0] - TILE // 2 + 2,
                               pac_start[1] - TILE // 2 + 2, TILE - 4, TILE - 4)
        self.pac_dir = (-1, 0)
        self.pac_want = (-1, 0)
        self.mouth = 0
        self.ghosts = [
            Ghost(9, 9, GHOST_COLORS[0], "blinky"),
            Ghost(11, 9, GHOST_COLORS[1], "pinky"),
            Ghost(9, 11, GHOST_COLORS[2], "inky"),
            Ghost(11, 11, GHOST_COLORS[3], "clyde"),
        ]
        self.fright_timer = 0

    def move_pac(self):
        speed = PAC_SPEED
        dx, dy = self.pac_want
        # try to turn
        test = self.pac.copy()
        test.x += dx * speed
        test.y += dy * speed
        ahead_col = int((self.pac.centerx + dx * TILE // 2) // TILE)
        ahead_row = int((self.pac.centery + dy * TILE // 2) // TILE)
        if not is_wall(ahead_col, ahead_row):
            self.pac_dir = self.pac_want
        dx, dy = self.pac_dir
        ahead_col = int((self.pac.centerx + dx * speed + dx * TILE // 3) // TILE)
        ahead_row = int((self.pac.centery + dy * speed + dy * TILE // 3) // TILE)
        if not is_wall(ahead_col, ahead_row):
            self.pac.x += dx * speed
            self.pac.y += dy * speed
        # snap to lane center for smooth turning
        if dx != 0:
            target = (self.pac.centery // TILE) * TILE + TILE // 2
            self.pac.centery += max(-speed, min(speed, target - self.pac.centery))
        else:
            target = (self.pac.centerx // TILE) * TILE + TILE // 2
            self.pac.centerx += max(-speed, min(speed, target - self.pac.centerx))

    def eat(self):
        cx, cy = self.pac.centerx // TILE, self.pac.centery // TILE
        pos = (cx, cy)
        if pos in self.dots:
            self.dots.remove(pos)
            self.score += 10
        elif pos in self.pellets:
            self.pellets.remove(pos)
            self.score += 50
            self.fright_timer = 400
            for g in self.ghosts:
                g.frightened = True

    def draw(self):
        self.screen.fill(BLACK)
        for r in range(ROWS):
            for c in range(COLS):
                if is_wall(c, r):
                    pygame.draw.rect(self.screen, BLUE,
                                     (c * TILE, r * TILE, TILE, TILE), 2)
        for (c, r) in self.dots:
            pygame.draw.circle(self.screen, WHITE,
                               (c * TILE + TILE // 2, r * TILE + TILE // 2), 3)
        for (c, r) in self.pellets:
            pygame.draw.circle(self.screen, WHITE,
                               (c * TILE + TILE // 2, r * TILE + TILE // 2), 7)
        # pacman with animated mouth
        angle_map = {(-1, 0): 180, (1, 0): 0, (0, -1): 90, (0, 1): 270}
        base = angle_map[self.pac_dir]
        mouth = abs(self.mouth) * 25
        pygame.draw.circle(self.screen, YELLOW, self.pac.center, TILE // 2 - 2)
        # cut mouth with black wedge
        pygame.draw.polygon(self.screen, BLACK, [
            self.pac.center,
            (self.pac.centerx + (TILE // 2) * pygame.math.Vector2(1, 0).rotate(-base + mouth).x,
             self.pac.centery + (TILE // 2) * pygame.math.Vector2(1, 0).rotate(-base + mouth).y),
            (self.pac.centerx + (TILE // 2) * pygame.math.Vector2(1, 0).rotate(-base - mouth).x,
             self.pac.centery + (TILE // 2) * pygame.math.Vector2(1, 0).rotate(-base - mouth).y),
        ])
        # ghosts
        for g in self.ghosts:
            color = (0, 0, 255) if g.frightened else g.color
            r = g.rect()
            pygame.draw.circle(self.screen, color, (r.centerx, r.centery - 3), r.width // 2)
            pygame.draw.rect(self.screen, color, (r.x, r.centery - 3, r.width, r.height // 2 + 2))
            pygame.draw.circle(self.screen, WHITE, (r.centerx - 5, r.centery - 4), 4)
            pygame.draw.circle(self.screen, WHITE, (r.centerx + 5, r.centery - 4), 4)
            pygame.draw.circle(self.screen, (0, 0, 139),
                               (r.centerx - 5 + g.dir[0] * 2, r.centery - 4 + g.dir[1] * 2), 2)
            pygame.draw.circle(self.screen, (0, 0, 139),
                               (r.centerx + 5 + g.dir[0] * 2, r.centery - 4 + g.dir[1] * 2), 2)
        # HUD
        hud = self.font.render(f"Score: {self.score}   Lives: {self.lives}", True, WHITE)
        self.screen.blit(hud, (8, ROWS * TILE + 10))
        if self.fright_timer > 0:
            ft = self.font.render("POWER!", True, (255, 255, 0))
            self.screen.blit(ft, (COLS * TILE - 90, ROWS * TILE + 10))
        pygame.display.flip()

    def game_over_screen(self, won):
        msg = "YOU WIN!" if won else "GAME OVER"
        text = self.big_font.render(msg, True, YELLOW if won else (255, 0, 0))
        rect = text.get_rect(center=(COLS * TILE // 2, ROWS * TILE // 2))
        self.screen.blit(text, rect)
        sub = self.font.render("Press R to restart, Q to quit", True, WHITE)
        self.screen.blit(sub, sub.get_rect(center=(COLS * TILE // 2, ROWS * TILE // 2 + 45)))
        pygame.display.flip()
        while True:
            for e in pygame.event.get():
                if e.type == pygame.QUIT:
                    return False
                if e.type == pygame.KEYDOWN:
                    if e.key == pygame.K_r:
                        self.score = 0
                        self.lives = 3
                        self.reset_level()
                        return True
                    if e.key == pygame.K_q:
                        return False

    def run(self):
        running = True
        while running:
            self.clock.tick(FPS)
            for e in pygame.event.get():
                if e.type == pygame.QUIT:
                    running = False
                elif e.type == pygame.KEYDOWN:
                    if e.key in DIRS:
                        self.pac_want = DIRS[e.key]
                    elif e.key == pygame.K_ESCAPE:
                        running = False

            self.move_pac()
            self.mouth = (self.mouth + 0.2) % 3

            self.eat()

            pac_tile = (self.pac.centerx // TILE, self.pac.centery // TILE)
            for g in self.ghosts:
                g.update(pac_tile, len(self.dots))
                if g.rect().colliderect(self.pac):
                    if g.frightened:
                        self.score += 200
                        g.reset()
                        g.frightened = False
                    else:
                        self.lives -= 1
                        if self.lives <= 0:
                            running = self.game_over_screen(False)
                        else:
                            self.reset_level()
                        break

            if self.fright_timer > 0:
                self.fright_timer -= 1
                if self.fright_timer == 0:
                    for g in self.ghosts:
                        g.frightened = False

            if not self.dots and not self.pellets:
                running = self.game_over_screen(True)

            self.draw()
        pygame.quit()


if __name__ == "__main__":
    Game().run()