Question

我正在制作一个简单的乒乓球游戏，而且我已经编写了大部分代码。

问题是，一旦球落下，如果继续移动球拍，它将从底部反弹回屏幕。一旦它错过了桨，我需要它永久地离开屏幕。

感谢任何反馈！提前谢谢！

L1_base.py（我的基本代码）：

import math
import random
import sys, pygame
from pygame.locals import *

import ball
import colors
import paddle

# draw the scene
def draw(screen, ball1, paddle1) :
   screen.fill((128, 128, 128))
   ball1.draw_ball(screen)
   paddle1.draw_paddle(screen)

#function to start up the main drawing
def main():

   pygame.init()
   width = 600
   height = 600
   screen = pygame.display.set_mode((width, height))

   ball1 = ball.Ball(300, 1, 40, colors.YELLOW, 0, 4)
   paddle1 = paddle.Paddle(200, 575, colors.GREEN, 100, 20)

   while 1:
      for event in pygame.event.get():
         if event.type == QUIT: sys.exit()
         elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_RIGHT:
               paddle1.update_paddle('right', 35)
            if event.key == pygame.K_LEFT:
               paddle1.update_paddle('left', 35)

      ball1.test_collide_top_ball(0)
      ball1.test_collide_bottom_ball(600, paddle1)
      ball1.update_ball()
      draw(screen, ball1, paddle1)
      pygame.display.flip()

if __name__ == '__main__':
   main()

ball.py（包含球类/方法）：

import pygame

class Ball:
   def __init__(self, x, y, radius, color, dx, dy):
      self.x = x
      self.y = y
      self.radius = radius
      self.color = color
      self.dx = dx
      self.dy = dy

   def draw_ball(self, screen):
      pygame.draw.ellipse(screen, self.color,
         pygame.Rect(self.x, self.y, self.radius, self.radius))

   def update_ball(self):
      self.x += self.dx
      self.y += self.dy

   def test_collide_top_ball(self, top_height):
      if (self.y <= top_height) and (self.dy < 0):
         self.dy *= -1

   def test_collide_bottom_ball(self, coll_height, paddle):
      if (self.y >= coll_height - self.radius - (600 - paddle.y)) and (self.x  >= paddle.x) and (self.x <= paddle.x + paddle.width) and (self.dy > 0):
         self.dy *= -1

paddle.py（包含paddle类/方法）：

import pygame

class Paddle:
   def __init__(self, x, y, c, w, h):
       self.x = x
       self.y = y
       self.color = c
       self.width = w
       self.height = h

   def draw_paddle(self, screen):
      pygame.draw.rect(screen, self.color,
         pygame.Rect(self.x, self.y, self.width, self.height), 0)

   def update_paddle(self, dir, dx):
      if (dir == 'left'):
         self.x = max(self.x - dx, 0)
      else:
         self.x = min(self.x + dx, 600 - self.width)

   def get_left(self):
      if (self.x < 300):
         return self.x

   def get_right(self):
      if (self.x >= 300):
         return self.x

Answer 1

你试图将过多的东西塞进if中的一个test_collide_bottom_ball语句中，这使得调试变得更加困难。在这种情况下，考虑到{strong>不到self.dy *= -1的所有原因，您应该更容易理解。切换方向是一种特权划分，应该只在特殊场合发生。

我已经离开了我的调试代码，以澄清我对问题的思考方式，还有另一个错误可以让球卡在桨中，但是你应该能够解决这个问题。请参阅以下代码：

 def test_collide_bottom_ball(self, coll_height, paddle):
    print paddle.x, paddle.width + paddle.x, self.x

    # shoot ball back to top when it has gone off the bottom
    if self.y > 600:
       self.y = 300
       return

    # ignore when the ball is far from the y access of the paddle
    if not self.y >= coll_height - self.radius - (600 - paddle.y):
       return

    # check that the current x plus raidus to find "too small" condition
    if self.x + self.radius <= paddle.x:
       print "self.x too small"
       return

    # for too big we have to consider the paddle width
    if self.x >= paddle.x + paddle.width:
       print "self.x too big"
       return

    # ok, looks like its time to switch directions!
    self.dy *= -1

P.S。使用pep8编码标准实用程序。在pep8之后编码并不困难，并且会让您头痛。

为什么球仍然从屏幕底部弹起？

1 个答案: