PyGobject（一百零二）Cairo系列——贪吃蛇游戏

例子

代码：

#!/usr/bin/env python3
# Created by xiaosanyu at 16/7/6
# section 152
TITLE = "Snake game"
DESCRIPTION = """
Snake is an older classic video game. It was first created in late 70s.
Later it was brought to PCs. In this game the player controls a snake.
The objective is to eat as many apples as possible.
Each time the snake eats an apple, its body grows.
The snake must avoid the walls and its own body.
This game is sometimes called Nibbles.
"""

import gi

gi.require_version("Gtk", "3.0")
from gi.repository import Gtk, Gdk, GLib

import cairo
import sys
import random
import os

FONT_SIZE = 14
WIDTH = 300
HEIGHT = 270
DOT_SIZE = 10
ALL_DOTS = int(WIDTH * HEIGHT / (DOT_SIZE * DOT_SIZE))
RAND_POS = 26
DELAY = 200
x = [0] * ALL_DOTS
y = [0] * ALL_DOTS


class Board(Gtk.DrawingArea):
    def __init__(self):
        super(Board, self).__init__()
        self.modify_bg(Gtk.StateFlags.NORMAL, Gdk.Color(0, 0, 0))
        self.set_size_request(WIDTH, HEIGHT)

        self.connect("draw", self.draw)
        self.init_game()

    def on_timer(self):
        if self.inGame:
            self.check_apple()
            self.check_collision()
            self.move()
            self.queue_draw()
            return True
        else:
            return False

    def init_game(self):
        self.left = False
        self.right = True
        self.up = False
        self.down = False
        self.inGame = True
        self.dots = 3
        for i in range(self.dots):
            x[i] = 50 - i * 10
            y[i] = 50
        try:
            self.dot = cairo.ImageSurface.create_from_png(os.path.join(os.path.dirname(__file__), "../data/dot.png"))
            self.head = cairo.ImageSurface.create_from_png(os.path.join(os.path.dirname(__file__), "../data/head.png"))
            self.apple = cairo.ImageSurface.create_from_png(
                    os.path.join(os.path.dirname(__file__), "../data/apple.png"))
        except Exception as e:
            print(e)
            sys.exit(1)
        self.locate_apple()
        self.start_game()

    def start_game(self):
        GLib.timeout_add(DELAY, self.on_timer)

    def draw(self, widget, cr):
        if self.inGame:
            cr.set_source_rgb(0.6, 0.6, 0.6)
            cr.paint()
            cr.set_source_surface(self.apple, self.apple_x, self.apple_y)
            cr.paint()
            for z in range(self.dots):
                if z == 0:
                    cr.set_source_surface(self.head, x[z], y[z])
                    cr.paint()
                else:
                    cr.set_source_surface(self.dot, x[z], y[z])
                    cr.paint()
        else:
            self.game_over(widget, cr)

    def game_over(self, widget, cr):
        w = widget.get_allocated_width()
        h = widget.get_allocated_height()
        (x, y, width, height, dx, dy) = cr.text_extents("Game Over")
        cr.set_source_rgb(65535, 0, 0)
        cr.set_font_size(FONT_SIZE)
        cr.move_to((w - width) / 2, h / 2)
        cr.show_text("Game Over")
        self.inGame = False

    def check_apple(self):
        if x[0] == self.apple_x and y[0] == self.apple_y:
            self.dots += 1
            self.locate_apple()

    def move(self):
        z = self.dots

        while z > 0:
            x[z] = x[(z - 1)]
            y[z] = y[(z - 1)]
            z -= 1
        if self.left:
            x[0] -= DOT_SIZE
        if self.right:
            x[0] += DOT_SIZE
        if self.up:
            y[0] -= DOT_SIZE
        if self.down:
            y[0] += DOT_SIZE

    def check_collision(self):
        z = self.dots
        while z > 0:
            if z > 4 and x[0] == x[z] and y[0] == y[z]:
                self.inGame = False
            z -= 1
        if y[0] > HEIGHT - DOT_SIZE:
            self.inGame = False
        if y[0] < 0:
            self.inGame = False
        if x[0] > WIDTH - DOT_SIZE:
            self.inGame = False
        if x[0] < 0:
            self.inGame = False

    def locate_apple(self):
        r = random.randint(0, RAND_POS)
        self.apple_x = r * DOT_SIZE
        r = random.randint(0, RAND_POS)
        self.apple_y = r * DOT_SIZE

    def on_key_down(self, event):
        key = event.keyval
        if key == Gdk.KEY_Left and not self.right:
            self.left = True
            self.up = False
            self.down = False

        if key == Gdk.KEY_Right and not self.left:
            self.right = True
            self.up = False
            self.down = False
        if key == Gdk.KEY_Up and not self.down:
            self.up = True
            self.right = False
            self.left = False
        if key == Gdk.KEY_Down and not self.up:
            self.down = True
            self.right = False
            self.left = False
        if key == Gdk.KEY_space:
            if self.inGame:
                self.inGame = False
            else:
                self.inGame = True
                self.start_game()


class Snake(Gtk.Window):
    def __init__(self):
        super(Snake, self).__init__()
        self.set_title('Snake')
        self.set_size_request(WIDTH, HEIGHT)

        self.set_resizable(False)
        self.move((Gdk.Screen.width() - WIDTH) / 2, (Gdk.Screen.height() - HEIGHT) / 2)
        self.board = Board()
        self.connect("key-press-event", self.on_key_down)
        self.add(self.board)
        self.connect("destroy", Gtk.main_quit)
        self.show_all()

    def on_key_down(self, widget, event):
        key = event.keyval
        self.board.on_key_down(event)


def main():
    Snake()
    Gtk.main()


if __name__ == "__main__":
    main()

代码下载地址：http://download.youkuaiyun.com/detail/a87b01c14/9594728