还不错，但是让我们使用一些面向对象的编程来稍微整理一下代码。这意味着对数据结构和行为进行分组并利用多态性。既然我们使用 pygame，那么我们就使用它的Sprite https://www.pygame.org/docs/ref/sprite.html类，但现在让我们忽略增强的东西。
我添加了一些评论以进行解释。
import pygame
from pygame.math import Vector2
import time, datetime
import sys
pygame.font.init()
pygame.init()
WIDTH = 1150
HEIGHT = 800
screen = pygame.display.set_mode((WIDTH, HEIGHT))
clock = pygame.time.Clock()
REDCAR_ORIGINAL = pygame.Surface((50, 30), pygame.SRCALPHA)
pygame.draw.polygon(REDCAR_ORIGINAL, (255, 0, 0), [(0, 30), (50, 20), (50, 10), (0, 0)])
# Everything car related goes into this class
class Car(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.speed = 5
# since we want to reset the car on a press of a button,
# let's have a reset function so we don't have duplicate code
self.reset()
def reset(self):
self.angle = 180
self.vel = Vector2(-self.speed, 0)
self.update_image((800, 500))
def update_image(self, center):
# since we update the image, rect and mask a lot,
# let's do this in a function, also
self.image = pygame.transform.rotate(REDCAR_ORIGINAL, self.angle)
self.rect = self.image.get_rect(center=center)
self.mask = pygame.mask.from_surface(self.image)
def update(self):
# basic input handling
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.angle += 5
self.vel.rotate_ip(-5)
elif keys[pygame.K_RIGHT]:
self.angle -= 5
self.vel.rotate_ip(5)
self.update_image(self.rect.center)
# ensure the car does not go out of screen
self.rect.move_ip(self.vel)
self.rect.clamp_ip(pygame.display.get_surface().get_rect())
red_car = Car()
all_sprites = pygame.sprite.Group(red_car)
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_r:
red_car.reset()
# clean little main loop, yeah
all_sprites.update()
screen.fill((50,200,50))
all_sprites.draw(screen)
pygame.display.flip()
dt = clock.tick(120)/1000
pygame.quit()
现在这可行了，让我们Boost班级。由于我们使用类，因此很容易添加多个类。每个人都有自己的状态；我们使用简单的减法来实现超时：
import pygame
from pygame.math import Vector2
import time, datetime
import sys
import pygame.freetype
pygame.font.init()
pygame.init()
WIDTH = 1150
HEIGHT = 800
screen = pygame.display.set_mode((WIDTH, HEIGHT))
clock = pygame.time.Clock()
REDCAR_ORIGINAL = pygame.Surface((50, 30), pygame.SRCALPHA)
pygame.draw.polygon(REDCAR_ORIGINAL, (255, 0, 0), [(0, 30), (50, 20), (50, 10), (0, 0)])
FONT = pygame.freetype.SysFont(None, 34)
# Everything car related goes into this class
class Car(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.speed = 3
# since we want to reset the car on a press of a button,
# let's have a reset function so we don't have duplicate code
self.reset()
def reset(self):
# if boost is > 0, we can drive faster
self.boost = 0
self.angle = 180
self.vel = Vector2(-self.speed, 0)
self.update_image((800, 500))
def update_image(self, center):
# since we update the image, rect and mask a lot,
# let's do this in a function, also
self.image = pygame.transform.rotate(REDCAR_ORIGINAL, self.angle)
self.rect = self.image.get_rect(center=center)
self.mask = pygame.mask.from_surface(self.image)
def update(self, dt):
if self.boost > 0:
self.boost -= dt
if self.boost < 0:
self.boost = 0
# basic input handling
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.angle += 5
self.vel.rotate_ip(-5)
elif keys[pygame.K_RIGHT]:
self.angle -= 5
self.vel.rotate_ip(5)
self.update_image(self.rect.center)
# double the speed if we have boost
self.rect.move_ip(self.vel * (2 if self.boost else 1))
# ensure the car does not go out of screen
self.rect.clamp_ip(pygame.display.get_surface().get_rect())
class Booster(pygame.sprite.Sprite):
def __init__(self, rect, cars):
super().__init__()
rect = pygame.rect.Rect(rect)
# a simple timeout. We do nothing if timeout > 0
self.timeout = 0
self.image = pygame.Surface(rect.size, pygame.SRCALPHA)
self.image.fill(pygame.color.Color('yellow'))
self.rect = rect
self.mask = pygame.mask.from_surface(self.image)
self.cars = cars
def update(self, dt):
disabled = self.timeout > 0
if disabled:
self.timeout -= dt
self.image.fill(pygame.color.Color('grey'))
FONT.render_to(self.image, (10, 10), str((self.timeout // 1000) + 1), pygame.color.Color('white'))
if self.timeout < 0:
self.timeout = 0
if disabled and self.timeout == 0:
# let's reactive
self.image.fill(pygame.color.Color('yellow'))
if not disabled:
for car in pygame.sprite.spritecollide(self, self.cars, False, pygame.sprite.collide_mask):
# let's boost the car
car.boost += 1000
# let's deactivate
self.timeout = 3000
break
red_car = Car()
cars = pygame.sprite.Group(red_car)
all_sprites = pygame.sprite.OrderedUpdates()
# see how easy it is now to create multiple Booster
for r in [(0, 340, 50, 150), (200, 200, 150, 50), (600, 600, 100, 100)]:
all_sprites.add(Booster(r, cars))
all_sprites.add(red_car)
dt = 0
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_r:
red_car.reset()
# clean little main loop, yeah
all_sprites.update(dt)
screen.fill((50,200,50))
all_sprites.draw(screen)
pygame.display.flip()
dt = clock.tick(120)
pygame.quit()
每个助推器有 3 秒的超时时间，并且会助推 1 秒。
我们利用OrderedUpdates https://www.pygame.org/docs/ref/sprite.html#pygame.sprite.OrderedUpdates以正确的顺序绘制我们的精灵，并且spritecollide https://www.pygame.org/docs/ref/sprite.html#pygame.sprite.spritecollide and collide_mask https://www.pygame.org/docs/ref/sprite.html#pygame.sprite.collide_mask用于碰撞检测。
这是我们正在运行的小游戏的糟糕 gif：
