如何在 Pygame 中为 Pong 设置碰撞检测

Question

我正在 Pygame 中构建 Pong 克隆。我不知道如何为球和桨添加碰撞检测，以便球会从桨上反弹。我怎样才能做到这一点？怎样才能让球击中球拍时反方向？

bif="bg.jpg"

import pygame, sys
from pygame.locals import *

pygame.init()
pygame.display.set_caption("Griffin West's Python Pong")
pygame.mixer.init()
sounda= pygame.mixer.Sound("Music.wav")

sounda.play()

screen=pygame.display.set_mode((1280,720),0,32)
background=pygame.image.load(bif).convert()

color1=(255,255,255)
color2=(255,255,0)
color3=(0,0,255)
color4=(0,255,0)
pos1=(640,0)
pos2=(640,720)
pos3=(640,360)
pos4=(0,360)
pos5=(1280,360)
radius=(100)
x1,y1=75,0
x2,y2=1175,0
x3,y3=1,1
clock=pygame.time.Clock()
speedx=750
speedy=750
movex1, movey1=0,0
movex2, movey2=0,0
s1=0
s2=0


while True:


    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        if event.type==KEYDOWN:
            if event.key==K_w:
                movey1=-2
            elif event.key==K_s:
                movey1=+2
            if event.key==K_UP:
                movey2=-2
            elif event.key==K_DOWN:
                movey2=+2
        if event.type==KEYUP:
            if event.key==K_w:
                movey1=0
            elif event.key==K_s:
                movey1=0
            if event.key==K_UP:
                movey2=0
            elif event.key==K_DOWN:
                movey2=0

    x1+=movex1
    y1+=movey1
    x2+=movex2
    y2+=movey2


    milli=clock.tick()
    seconds=milli/1000.0
    dx=seconds*speedx
    dy=seconds*speedy
    x3+=dx
    y3+=dy

    if x3>1280: 
        x3+=-dx  # get ball out of the wall
        speedx = -speedx  # change direction
        s1=s1+1
    if y3>720:
        y3+=-dy
        speedy = -speedy
    if x3<0:
        x3+dx
        speedx = -speedx
        x3=x3+1
        s2=s2+1
    if y3<0:
        y3=y3+1
        y3+=dy
        speedy = -speedy
    if x3<=y3y3+30:
        speedx = -speedy


    screen.blit(background, (0,0))

    screen.lock()
    pygame.draw.line(screen, color1, pos1, pos2, 1)
    pygame.draw.circle(screen, color1, pos3, radius, 1)
    pygame.draw.circle(screen, color1, pos4, radius, 1)
    pygame.draw.circle(screen, color1, pos5, radius, 1)
    pygame.draw.rect(screen, color3, Rect((x1,y1),(30,100)))
    pygame.draw.rect(screen, color2, Rect((x2,y2),(30,100)))
    pygame.draw.circle(screen, color4, (int(x3),int(y3)), 15)

    screen.unlock()
    myfont = pygame.font.SysFont("Press Start 2P", 50)
    myfont2 = pygame.font.SysFont("Press Start 2P", 25)
    label = myfont.render("Python", 1, (255,0,0))
    screen.blit(label, (494, 115))
    label = myfont.render("Pong", 1, (255,0,0))
    screen.blit(label, (544, 175))
    label = myfont2.render("Player 1: "+str(s1), 1, (255,255,255))
    screen.blit(label, (25, 675))
    label = myfont2.render("Player 2: "+str(s2), 1, (255,255,255))
    screen.blit(label, (950, 675))
    pygame.display.update()

Answer 1

This answer 有一个包含碰撞检测的示例 pong 实现。具体来说，您会对下面列出的代码中的bounce 方法感兴趣。

在 Pong 类中：

def move_all(self):
    for obj in self.p1, self.p2, self.ball:
        obj.move()
        if obj is not self.ball:
            obj.bounce(self.ball)

在 Paddle 类中：

def bounce(self, ball):
    minimum = self.size.x + ball.radius
    if self.position.x != ball.position.x and self.overlap(ball, minimum):
        if not self.just_bounced:
            self.just_bounced = True
            self.score += abs(ball.velocity.y)
        sign = +1 if self.position.x < ball.position.x else -1
        if self.collision_area == self.PART.center:
            ball.position.x = self.position.x + minimum * sign
        else:
            ball.position.adjust(self.middle_point, minimum)
        ball.velocity.x = copy_sign(ball.velocity.x, sign)
        ball.change_speed()
    else:
        self.just_bounced = False

在 Ball 类中：

def bounce(self):
    if self.position.y - self.radius < 0:
        self.position.y = self.radius
        self.velocity.y = copy_sign(self.velocity.y, +1)
        self.change_speed()
    elif self.position.y + self.radius > self.board.y:
        self.position.y = self.board.y - self.radius
        self.velocity.y = copy_sign(self.velocity.y, -1)
        self.change_speed()

Answer 2

制作一个 if 语句，检查球的 x 坐标是否超出了球拍的 x 坐标，以及球的 y 坐标是否在球拍的顶部和底部 y 坐标内。如果是这样，将球的 x 速度乘以 -1。