先是素材：

背景

精灵

所有素材均取自此书

接下来就是精灵类的创建了：

 (self)
 self.master_image === -1= 1= 1=== 1============rect == (rect.width // width) * (rect.height // height) - 1 update(self, current_time, rate=30 current_time > self.last_time ++= 1 self.frame >== self.frame !== (self.frame % self.columns) *= (self.frame // self.columns) *=== self.frame

将精灵类“放置”到游戏屏幕上，并加上背景

pygame.init()
screen = pygame.display.set_mode((800, 600))
font = pygame.font.Font(None, 24)
framerate = pygame.time.Clock()

bg = pygame.image.load("background.png").convert_alpha()
pl = pygame.image.load('caveman.png').convert_alpha()# 创建精灵组group = pygame.sprite.Group()


player = MySprite(screen)
player.load("caveman.png", 50, , 8)
player.first_frame = 1player.last_frame = 7player.position = 400, 303group.add(player)while True:for event in pygame.event.get():if event.type == QUIT:
 sys.exit()# 设置帧数framerate.tick(30)
 ticks = pygame.time.get_ticks()

这样的话精灵就在画布上了，我们得让它能左右移动：

keys = pygame.key.get_pressed()if keys[K_ESCAPE]:
 sys.exit()if keys[K_RIGHT]:
 player.X += 8if keys[K_LEFT]:if player.X > 0:
 player.X -= 8

然后实现跳跃及二段跳跃

这里需要说下二段跳跃的注意点：

1.直到落地前，只能跳两次，也就是说精灵进行二次跳跃后不能再跳了

2.按下空格后，精灵的加速度重置

,这需要修改前面的代码:

jump_vel = 0.0# 设置一个记录跳跃次数的变量space_number = 0# 跳跃判断player_jumping = False
player_start_y = player.Ywhile True:for event in pygame.event.get():if event.type == QUIT:
 sys.exit()if event.type == KEYDOWN:if event.key == K_SPACE:# 跳跃次数小于2次时，if space_number < 2:
 jump_vel = -15.0space_number += 1player_jumping = True

 keys = pygame.key.get_pressed()if keys[K_ESCAPE]:
 sys.exit()if keys[K_RIGHT]:
 player.X += 8if keys[K_LEFT]:if player.X > 0:
 player.X -= 8# 设置帧数framerate.tick(30)
 ticks = pygame.time.get_ticks()# 当按下空格后，jump_vel变量不断变大，直到接触地面if player_jumping:
 player.Y += jump_vel
 jump_vel += 2# 落地后，重置跳跃速度和其他判断变量if player.Y >= player_start_y:
 player_jumping = False
 player.Y = player_start_y
 jump_vel = 0
 space_number = 0# 创建背景 screen.blit(bg, (0, 0))# 精灵组更新group.update(ticks, 50)
 group.draw(screen)

 pygame.display.update()

所有代码:

import sys, time, random, math, pygamefrom pygame.locals import *class MySprite(pygame.sprite.Sprite):def __init__(self, target):
 pygame.sprite.Sprite.__init__(self)
 self.master_image = None
 self.frame = 0
 self.old_frame = -1self.frame_width = 1self.frame_height = 1self.first_frame = 0
 self.last_frame = 0
 self.columns = 1self.last_time = 0# 　　使用property方法，让精灵类对坐标操作更方便def _getx(self):return self.rect.xdef _setx(self, value):
 self.rect.x = value

 X = property(_getx, _setx)def _gety(self):return self.rect.ydef _sety(self, value):
 self.rect.y = value

 Y = property(_gety, _sety)def _getpos(self):return self.rect.topleftdef _setpos(self, pos):
 self.rect.topleft = pos

 position = property(_getpos, _setpos)def load(self, filename, width, height, columns):
 self.master_image = pygame.image.load(filename).convert_alpha()
 self.frame_width = width
 self.frame_height = height
 self.rect = Rect(0, 0, width, height)
 self.columns = columns
 rect = self.master_image.get_rect()
 self.last_frame = (rect.width // width) * (rect.height // height) - 1def update(self, current_time, rate=30):# 　　更新帧数if current_time > self.last_time + rate:
 self.frame += 1if self.frame > self.last_frame:
 self.frame = self.first_frame
 self.last_time = current_time# 当帧数发生改变时，创建新的图片if self.frame != self.old_frame:
 frame_x = (self.frame % self.columns) * self.frame_width
 frame_y = (self.frame // self.columns) * self.frame_height
 rect = Rect(frame_x, frame_y, self.frame_width, self.frame_height)
 self.image = self.master_image.subsurface(rect)
 self.old_frame = self.frame

pygame.init()
screen = pygame.display.set_mode((800, 600))
font = pygame.font.Font(None, 24)
framerate = pygame.time.Clock()

bg = pygame.image.load("background.png").convert_alpha()
pl = pygame.image.load('caveman.png').convert_alpha()# 创建精灵组group = pygame.sprite.Group()


player = MySprite(screen)
player.load("caveman.png", 50, , 8)
player.first_frame = 1player.last_frame = 7player.position = 400, 303group.add(player)


jump_vel = 0.0# 设置一个记录跳跃次数的变量space_number = 0# 跳跃判断player_jumping = False
player_start_y = player.Ywhile True:for event in pygame.event.get():if event.type == QUIT:
 sys.exit()if event.type == KEYDOWN:if event.key == K_SPACE:# 跳跃次数小于2次时，if space_number < 2:
 jump_vel = -15.0space_number += 1player_jumping = True

 keys = pygame.key.get_pressed()if keys[K_ESCAPE]:
 sys.exit()if keys[K_RIGHT]:
 player.X += 8if keys[K_LEFT]:if player.X > 0:
 player.X -= 8# 设置帧数framerate.tick(30)
 ticks = pygame.time.get_ticks()# 当按下空格后，jump_vel变量不断变大，直到接触地面if player_jumping:
 player.Y += jump_vel
 jump_vel += 2# 落地后if player.Y >= player_start_y:
 player_jumping = False
 player.Y = player_start_y
 jump_vel = 0
 space_number = 0
 rush_number = 0# 创建背景 screen.blit(bg, (0, 0))# 精灵组更新group.update(ticks, 50)
 group.draw(screen)

 pygame.display.update()

这样，一个粗糙的、会二段跳的精灵就完成了。

很感谢这本书提供单次跳跃的思路，让我有思考二段跳的想法。其实像二段跳这类看上去容易，但实现其实还是需要思考一番的。