不得不承认《Python游戏编程入门》这本书翻译、排版非常之烂，但是里面的demo还是很好的，之前做了些改编放到这里。
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：
class MySprite(pygame.sprite.Sprite):
def __init__(self, target):
pygame.sprite.Sprite.__init__(self)
self.master_image = None
self.frame = 0
self.old_frame = -1
self.frame_width = 1
self.frame_height = 1
self.first_frame = 0
self.last_frame = 0
self.columns = 1
self.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.x def _setx(self, value):
self.rect.x = value X = property(_getx, _setx) def _gety(self):
return self.rect.y def _sety(self, value):
self.rect.y = value Y = property(_gety, _sety) def _getpos(self):
return self.rect.topleft def _setpos(self, pos):
self.rect.topleft = pos position = property(_getpos, _setpos) # load方法中定义了图片位置，长宽和帧的列数，由此来将素材切成一帧一帧
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) - 1 def update(self, current_time, rate=30):
# 更新帧数
if current_time > self.last_time + rate:
self.frame += 1
if 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
将精灵类“放置”到游戏屏幕上，并加上背景
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 += 8
if keys[K_LEFT]:
if player.X > 0:
player.X -= 8
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, 64, 8)
player.first_frame = 1
player.last_frame = 7
player.position = 400, 303
group.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()
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.Y while 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 = -15.0
space_number += 1
player_jumping = True keys = pygame.key.get_pressed()
if keys[K_ESCAPE]:
sys.exit()
if keys[K_RIGHT]:
player.X += 8
if 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, pygame
from 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 = -1
self.frame_width = 1
self.frame_height = 1
self.first_frame = 0
self.last_frame = 0
self.columns = 1
self.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.x def _setx(self, value):
self.rect.x = value X = property(_getx, _setx) def _gety(self):
return self.rect.y def _sety(self, value):
self.rect.y = value Y = property(_gety, _sety) def _getpos(self):
return self.rect.topleft def _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) - 1 def update(self, current_time, rate=30):
# 更新帧数
if current_time > self.last_time + rate:
self.frame += 1
if 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, 64, 8)
player.first_frame = 1
player.last_frame = 7
player.position = 400, 303
group.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.Y while 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 = -15.0
space_number += 1
player_jumping = True keys = pygame.key.get_pressed()
if keys[K_ESCAPE]:
sys.exit()
if keys[K_RIGHT]:
player.X += 8
if 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。