How to make the ball bounce back after hitting the paddle?

Question

I am working on a clone of Breakout and I've already made a ball, bricks and a paddle that can be moved freely by keyboard, the ball can hit the bricks, it can hit the window, but it can’t hit the paddle. It just go through the paddle and hit the window below the paddle then bounce back. I don't know what to do. Sorry about the lack of comments I am really new to this.

import pygame
from pygame.locals import QUIT, KEYDOWN, K_LEFT, K_RIGHT
from pygame.locals import Rect
import math
pygame.init()
SURFACE = pygame.display.set_mode((400,300))
pygame.display.set_caption("Game Window")
FPSCLOCK = pygame.time.Clock()
class Block:
    def __init__(self, color, rect):
        self.color = color
        self.rect = rect
    def draw(self):
        pygame.draw.rect(SURFACE, self.color, self.rect)
    def delete(self):
        blocks.remove(block)
pw = 40
ph = 5
paddle = Block((0, 0, 255),Rect(180, 295,pw, ph))
pygame.key.set_repeat(30, 30)
class Ball:
    def __init__(self,a,b,c,d):
        self.color=a
        self.rect=b
        self.dir=c
        self.speed=d
    def draw(self):
        pygame.draw.ellipse(SURFACE, ball_color, ball_rect)
    def move(self):
        ball_rect.centerx += math.cos(math.radians(self.dir))*self.speed
        ball_rect.centery -= math.sin(math.radians(self.dir))*self.speed
        if ball_rect.centerx <=0 or ball_rect.centerx >= 400:
            self.dir = 180 - self.dir
        if ball_rect.centery <= 0 or ball_rect.centery >= 300:
            self.dir = -self.dir
    def bounce(self):
        self.dir -= 180
left=6
top=30
width=45
height=20
color=(200,50,200)
blocks = []
for i in range(4):
    for j in range(8):
        rect = Rect(left, top, width, height)
        blocks.append(Block(color, rect))
        left += 49
    left = 6
    top += 24
ball_rect = Rect(150,100,10,10)
ball_color = (255,255,0)
ball = Ball(ball_color, ball_rect, 60, 5)
num=0
while True:
    SURFACE.fill((0,0,0))
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        elif event.type == KEYDOWN:
            if event.key == K_LEFT and paddle.rect.centerx-pw/2 > 0:
                paddle.rect.centerx -= 10
            elif event.key == K_RIGHT and paddle.rect.centerx+pw/2 < 400:
                paddle.rect.centerx += 10
    SURFACE.fill((0,0,0))
    paddle.draw()
    for block in blocks:
        block.draw()
    ball.draw()
    ball.move()
    for block in blocks:
        if ball.rect.colliderect(block.rect)==True:
            Block.delete(blocks)
            ball.bounce()
    pygame.display.update()
    FPSCLOCK.tick(60)

score 0 · Answer 1 · answered Dec 11 '21 at 10:40

The collision test with the paddle is missing. Also, before iterating and removing items from the list, make a copy of the list (see How to remove items from a list while iterating?):

while True:
    # event loop
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        elif event.type == KEYDOWN:
            if event.key == K_LEFT and paddle.rect.centerx-pw/2 > 0:
                paddle.rect.centerx -= 10
            elif event.key == K_RIGHT and paddle.rect.centerx+pw/2 < 400:
                paddle.rect.centerx += 10
    
    # move ball
    ball.move()

    # collision test
    if ball.rect.colliderect(paddle.rect):      # <---
        ball.bounce()
    for block in blocks[:]:                     # <---
        if ball.rect.colliderect(block.rect):
            Block.delete(blocks)
            ball.bounce()
    
    # draw scene 
    SURFACE.fill((0,0,0))
    paddle.draw()
    for block in blocks:
        block.draw()
    ball.draw()
    pygame.display.update()
    FPSCLOCK.tick(60)

The bouncing may not always be correct. I suggest reading Sometimes the ball doesn't bounce off the paddle in pong game.

How to make the ball bounce back after hitting the paddle?

1 Answers1