撞“墙”时如何在pygame中改变圆圈的方向

如何解决撞“墙”时如何在pygame中改变圆圈的方向

我想知道如何在使用 pygame 撞到“墙”时改变正方形的方向。下面是我的代码：

"""

    Date: Nov 4,2020

    Description: Animating Shapes with pygame
"""


import pygame


def main():
    '''This function defines the 'mainline logic' for our game.'''
    # I - INITIALIZE
    pygame.init()

    # disPLAY
    screen = pygame.display.set_mode((640,480))
    pygame.display.set_caption("Crazy Shapes Animation")

    # ENTITIES
    background = pygame.Surface(screen.get_size())
    background = background.convert()
    background.fill((255,255,255))  # white background

    # Make a red 25 x 25 Box
    red_Box = pygame.Surface((25,25))
    red_Box = red_Box.convert()
    red_Box.fill((255,0))

    # A - ACTION (broken into ALTER steps)

    # ASSIGN
    clock = pygame.time.Clock()
    keepGoing = True

    red_Box_x = 0  # Assign starting (x,y)
    red_Box_y = 200  # for our red Box

    # LOOP
    while keepGoing:

        # TIMER
        clock.tick(30)

        # EVENT HANDLING
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                keepGoing = False

        # change x coordinate of Box
        red_Box_x += 5
        # check boundaries,to reset Box to left-side
        if red_Box_x > screen.get_width():
            red_Box_x = 0

        # REFRESH (update window)
        screen.blit(background,(0,0))
        screen.blit(red_Box,(red_Box_x,red_Box_y))  # blit Box at new (x,y) location
        pygame.display.flip()

    # Close the game window
    pygame.quit()


# Call the main function
main()

当它碰到最右侧的墙壁时，我希望它反转方向并返回最左侧的墙壁。然后它继续无限地撞击墙壁。这是一个学校作业，我在网上找不到任何解决方案，所以如果你能帮助我就好了！

解决方法

为运动使用变量 (move_x) 而不是常量。当物体撞墙时反转变量的值 (move_x *= -1)：

def main():
    # [...]

    move_x = 5

    # LOOP
    while keepGoing:
        # [...]

        # change x coordinate of box
        red_box_x += move_x
        # check boundaries,to reset box to left-side
        if red_box_x >= screen.get_width():
            red_box_x = screen.get_width()
            move_x *= -1
        if red_box_x <= 0:
            red_box_x = 0
            move_x *= -1

        # [...]