Question

我第一次玩pygame，尝试让多个矩形在屏幕上移动。这是我的代码：

import pygame

pygame.init()

scrWidth = 1200
scrHeigth = 900
done = False
rectangles = []

screen = pygame.display.set_mode((scrWidth, scrHeigth))
clock = pygame.time.Clock()

class Rectangle:
    speed = [1,1]
    colourSpeed = 300
    colourID = 0
    colour = (0, 0, 255)
    size = 60

    def __init__(self, name = "", x=0, y=0, speed=False, colour=False, size=False):
        self.name = name
        self.x = x
        self.y = y
        self.doesSpeed = speed
        self.doesColour = colour
        self.doesSize = size

    def draw(self):
        pygame.draw.rect(screen, self.colour, pygame.Rect(self.x, self.y, self.size, self.size))

    def checkCollision(self):
        if self.x < 0 or self.x > scrWidth-self.size:
            self.speed[0] = -self.speed[0]
        if self.y < 0 or self.y > scrHeigth-self.size:
            self.speed[1] = -self.speed[1]

    def move(self):
        self.x += self.speed[0]
        self.y += self.speed[1]

    def changeColour(self):
        self.colourID = (self.colourID+1)%self.colourSpeed
        if 0 <= self.colourID < (self.colourSpeed/3):
            self.colour = (0, 0, 255)
        elif (self.colourSpeed/3) <= self.colourID < (2*self.colourSpeed/3):
            self.colour = (0, 255, 0)
        elif (2*self.colourSpeed/3) <= self.colourID < self.colourSpeed:
            self.colour = (255, 0, 0)




rect1 = Rectangle("rect1", 30, 30, False, True, False)
rectangles.append(rect1)
rect2 = Rectangle("rect2", 300, 300)
rectangles.append(rect2)


while not done:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done=True

    screen.fill((0, 0, 0))
    for obj in rectangles:
        obj.checkCollision()
        if obj.doesColour: obj.changeColour()
        obj.move()
        obj.draw()

    pygame.display.flip()
    clock.tick(60)

问题是当矩形与屏幕边缘碰撞时，所有矩形都会改变方向（速度）。但是，如果我制作不同速度的矩形，则不会发生这种情况。

ex：rect1的速度为[1,1]，rect2的速度为[2,2]。

造成这种情况的原因是什么？如何解决？

Answer 1

将speed，colourSpeed，colourID，颜色，大小移动到 init 方法。

此时，字段被定义为类字段，因此它们将针对所有矩形进行全局更改。

<强>解决方案：

def __init__(self, name = "", x=0, y=0, speed=False, colour=False, size=False):
        self.name = name
        self.x = x
        self.y = y
        self.doesSpeed = speed
        self.doesColour = colour
        self.doesSize = size
        # here it comes
        self.speed = [1,1]
        self.colourSpeed = 300
        self.colourID = 0
        self.colour = (0, 0, 255)
        self.size = 60

Python变量会在每个对象中发生变化

1 个答案: