game.py

import sys
import pygame
import pymunk
import colors
import const
import helper

from pygame.locals import *
from pymunk import pygame_util
from ball import Ball
from paddle import Paddle

class Game():

    FPS = 60

    def __init__(self):
        self.screen = pygame.display.get_surface()
        self.background = self.screen.copy()
        self.clock = pygame.time.Clock()
        self.sprites = helper.Group()
        self.space = pymunk.Space()

        self.ball = Ball(self.space, (400, 20))
        self.paddle = Paddle(self.space, (40, 250))
        self.sprites.add(self.ball)
        self.sprites.add(self.paddle)

        self.walls = [
            self._create_wall((0, const.SCREEN_HEIGHT), (0, 0)),
            self._create_wall((const.SCREEN_WIDTH - 1, const.SCREEN_HEIGHT),
                              (const.SCREEN_WIDTH - 1, 0)),
            self._create_wall((0, const.SCREEN_HEIGHT),
                          (const.SCREEN_WIDTH, const.SCREEN_HEIGHT)),
            self._create_wall((0, 1), (const.SCREEN_WIDTH, 1))]

        self.space.add(self.walls)

    def _create_wall(self, from_, to):
        segment = pymunk.Segment(self.space.static_body,
                                 from_, to, 1)
        segment.elasticity = 1.
        return segment

    def main(self):
        self.background.fill(colors.BLACK)
        while True:

            dt = self.clock.tick(Game.FPS) / 1000.

            for event in pygame.event.get():
                if event.type == QUIT or (event.type == KEYDOWN and
                    event.key == K_ESCAPE):
                    pygame.quit()
                    sys.exit()

            pygame.display.flip()
            self.update(dt)
            self.draw()

    def update(self, dt):
        self.space.step(1./Game.FPS)
        self.sprites.update(dt)
        print(self.ball.body.velocity)
        print(self.paddle.body.velocity)

    def draw(self):
        self.screen.blit(self.background, (0, 0))
        #self.sprites.draw(self.screen)
        pygame_util.draw(self.screen, self.space)