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pygame-tutorial / 13-gravity.py

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import pygame

class Sprite(pygame.sprite.Sprite):
    def __init__(self, image, location):
        super(Sprite, self).__init__()
        self.image = pygame.image.load(image)
        self.rect = pygame.rect.Rect(location, self.image.get_size())

class Player(Sprite):
    resting = False
    dy = 0
    def update(self, dt, game):
        last = self.rect.copy()

        key = pygame.key.get_pressed()
        if key[pygame.K_LEFT]:
            self.rect.x -= 300 * dt
        if key[pygame.K_RIGHT]:
            self.rect.x += 300 * dt

        if self.resting and key[pygame.K_SPACE]:
            self.dy = -500
        self.dy = min(400, self.dy + 40)

        self.rect.y += self.dy * dt

        new = self.rect
        self.resting = False
        for cell in pygame.sprite.spritecollide(self, game.walls, False):
            cell = cell.rect
            if last.right <= cell.left and new.right > cell.left:
                new.right = cell.left
            if last.left >= cell.right and new.left < cell.right:
                new.left = cell.right
            if last.bottom <= cell.top and new.bottom > cell.top:
                self.resting = True
                new.bottom = cell.top
                self.dy = 0
            if last.top >= cell.bottom and new.top < cell.bottom:
                new.top = cell.bottom
                self.dy = 0

class Game(object):
    def main(self, screen):
        clock = pygame.time.Clock()

        sprites = pygame.sprite.OrderedUpdates()
        background = Sprite('background.png', (0, 0))
        sprites.add(background)
        player = Player('player.png', (320, 240))
        sprites.add(player)
        self.walls = pygame.sprite.Group()
        for x in range(0, 640, 32):
            for y in range(0, 480, 32):
                if x in (0, 640-32) or y in (0, 480-32):
                    self.walls.add(Sprite('block.png', (x, y)))
        sprites.add(self.walls)

        while 1:
            dt = clock.tick(30)

            for event in pygame.event.get():
                if event.type == pygame.QUIT:
                    return
                if event.type == pygame.KEYDOWN and event.key == pygame.K_ESCAPE:
                    return

            sprites.update(dt / 1000., self)
            sprites.draw(screen)
            pygame.display.flip()

if __name__ == '__main__':
    pygame.init()
    screen = pygame.display.set_mode((640, 480))
    Game().main(screen)