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pygame 精灵的行走及二段跳实现方法

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

技术分享

精灵

技术分享

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

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 = 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 += 8    if 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 = Falseplayer_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 = -15.0                    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, 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 = -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.framepygame.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 = 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 = Falseplayer_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 = -15.0                    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。

 

pygame 精灵的行走及二段跳实现方法