我正在重写一个简单的游戏。之前我只是使用例如pygame.draw.circle((来创建对象并与之交互。
然而，对于更复杂的任务(如与多边形的碰撞(，需要使用遮罩。
这就是我之前让球在墙上反弹的方式：
def bounce(self):
# Right boundary
if self.x > width - self.radius:
self.x = 2 * (width - self.radius) - self.x
self.angle = - self.angle
self.velocity = Vector2(self.velocity) * elasticity
# Left boundary
elif self.x < self.radius:
self.x = 2 * self.radius - self.x
self.angle = - self.angle
self.velocity = Vector2(self.velocity) * elasticity
# Top boundary
if self.y > height - self.radius:
self.y = 2 * (height - self.radius) - self.y
self.angle = math.pi - self.angle
self.velocity = Vector2(self.velocity) * elasticity
# Bottom boundary
elif self.y < self.radius:
self.y = 2 * self.radius - self.y
self.angle = math.pi - self.angle
self.velocity = Vector2(self.velocity) * elasticity
但现在有了口罩，它只会在撞到墙上时停止，但不再反弹。
完整代码：
import pygame
from pygame.math import Vector2
import math
width = 1150
height = 800
# Colors
GOLD = (255, 215, 0)
drag = 0.999 # Between 0 and 1
elasticity = 0.75 # Between 0 and 1
pygame.init()
screen = pygame.display.set_mode((width, height))
clock = pygame.time.Clock()
# Define game object class
class Circle:
def __init__(self, coordinates, velocity, angle, radius, objectColor):
self.x = coordinates[0]
self.y = coordinates[1]
self.velocity = velocity
self.angle = angle
self.radius = radius
self.objectColor = objectColor
self.initSurface = pygame.Surface((self.radius*2, self.radius*2), pygame.SRCALPHA)
self.rectangle = self.initSurface.get_rect(center=Vector2(self.x, self.y))
self.surface = self.initSurface
self.mask = None
self.draw()
def draw(self):
pygame.draw.circle(self.initSurface, self.objectColor, [self.radius, self.radius], self.radius)
self.mask = pygame.mask.from_surface(self.initSurface)
def move(self):
self.x += self.velocity[0]
self.y += self.velocity[1]
self.velocity = Vector2(self.velocity) * drag
self.rectangle.center = Vector2(self.x, self.y)
def bounce(self):
# Right boundary
if self.x > width - self.radius:
self.x = 2 * (width - self.radius) - self.x
self.angle = - self.angle
self.velocity = Vector2(self.velocity) * elasticity
# Left boundary
elif self.x < self.radius:
self.x = 2 * self.radius - self.x
self.angle = - self.angle
self.velocity = Vector2(self.velocity) * elasticity
# Top boundary
if self.y > height - self.radius:
self.y = 2 * (height - self.radius) - self.y
self.angle = math.pi - self.angle
self.velocity = Vector2(self.velocity) * elasticity
# Bottom boundary
elif self.y < self.radius:
self.y = 2 * self.radius - self.y
self.angle = math.pi - self.angle
self.velocity = Vector2(self.velocity) * elasticity
class Polygon:
def __init__(self, coordinates, velocity, angle, pointList, objectColor):
self.x = coordinates[0]
self.y = coordinates[1]
self.velocity = velocity
self.angle = angle
self.pointList = pointList
self.objectColor = objectColor
self.initSurface = pygame.Surface((max(self.pointList, key=lambda item: item[0])[0],
max(self.pointList, key=lambda item: item[1])[1]), pygame.SRCALPHA)
self.rectangle = self.initSurface.get_rect(center=Vector2(self.x, self.y))
self.surface = self.initSurface
self.mask = None
self.draw()
def draw(self):
pygame.draw.polygon(self.initSurface, self.objectColor, self.pointList)
self.mask = pygame.mask.from_surface(self.initSurface)
def move(self):
self.x += self.velocity[0]
self.y += self.velocity[1]
self.rectangle.center = Vector2(self.x, self.y)
def rotate(self, angle):
self.angle += angle
self.velocity.rotate_ip(-angle)
surface = pygame.transform.rotate(self.initSurface, self.angle)
self.rectangle = surface.get_rect(center=self.rectangle.center)
# We need a new mask after the rotation.
self.mask = pygame.mask.from_surface(surface)
self.surface = surface
# Colliding game object particles
def collide(p1, p2):
offset = p1.rectangle[0] - p2.rectangle[0], p1.rectangle[1] - p2.rectangle[1]
overlap = myBall.mask.overlap(p1.mask, offset)
if overlap:
p2.velocity = Vector2(p1.velocity) * 1.4
# Images
BG_IMG = pygame.Surface((1150, 800))
BG_IMG.fill((30, 120, 30))
# Init Ball and car (input)
myBall = Circle(Vector2(575, 400), Vector2(0, 0), 0, 60, GOLD)
myInput = Polygon(Vector2(470, 370), Vector2(3, 0), 0, [(0, 0), (50, 10), (50, 20), (0, 30)], GOLD)
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
myInput.rotate(5)
elif keys[pygame.K_RIGHT]:
myInput.rotate(-5)
# Move the car
myInput.move()
# Move the ball
myBall.velocity *= .99 # Friction
myBall.move()
myBall.bounce()
# Car collision.
collide(myInput, myBall)
# Drawing
screen.blit(BG_IMG, (0, 0))
screen.blit(myBall.surface, myBall.rectangle)
screen.blit(myInput.surface, myInput.rectangle)
pygame.display.flip()
clock.tick(60)
pygame.quit()
我在这里错过了什么？我再也看不透了。
在bounce方法中，你会使速度变小，你永远不会翻转它，所以，只需添加一个减号，它就会反弹回来，而不是越来越慢地移动到反弹中
self.velocity = Vector2(-self.velocity) * elasticity