pygame-KidsCanCode系列jumpy-part9-使用spritesheet

做过前端的兄弟应该都知道css sprite(也称css精灵),这是一种常用的减少http请求次数的优化手段。把很多小图拼成一张大图,只加载1次,然后用css定位到不区的区域,从而展示不同的图片。游戏中也是类似的道理,如下图:

每一个小图片,都有自己的x,y,width,height信息,通常会放在一个xml中,类似:

  1 <TextureAtlas imagePath="sprites.png">
  2     <SubTexture name="bronze_1.png" x="707" y="296" width="84" height="84"/>
  3     <SubTexture name="bronze_2.png" x="826" y="206" width="66" height="84"/>
  4     <SubTexture name="bronze_3.png" x="899" y="116" width="50" height="84"/>
  5     <SubTexture name="bronze_4.png" x="670" y="406" width="14" height="84"/>
  6     <SubTexture name="bubble.png" x="0" y="1662" width="211" height="215"/>
  7     <SubTexture name="bunny1_hurt.png" x="382" y="946" width="150" height="174"/>
  8     <SubTexture name="bunny1_jump.png" x="382" y="763" width="150" height="181"/>
  9     <SubTexture name="bunny1_ready.png" x="614" y="1063" width="120" height="191"/>
 10     <SubTexture name="bunny1_stand.png" x="690" y="406" width="120" height="201"/>
 11     <SubTexture name="bunny1_walk1.png" x="678" y="860" width="120" height="201"/>
 12     <SubTexture name="bunny1_walk2.png" x="692" y="1458" width="120" height="207"/>
 13     <SubTexture name="bunny2_hurt.png" x="411" y="1866" width="150" height="174"/>
 14     <SubTexture name="bunny2_jump.png" x="416" y="1660" width="150" height="181"/>
 15     <SubTexture name="bunny2_ready.png" x="581" y="1265" width="121" height="191"/>
 16     <SubTexture name="bunny2_stand.png" x="584" y="0" width="121" height="201"/>
 17     <SubTexture name="bunny2_walk1.png" x="584" y="203" width="121" height="201"/>
 18     <SubTexture name="bunny2_walk2.png" x="678" y="651" width="121" height="207"/>
 19     <SubTexture name="cactus.png" x="707" y="134" width="117" height="160"/>
 20     <SubTexture name="carrot.png" x="820" y="1733" width="78" height="70"/>
 21     <SubTexture name="carrot_gold.png" x="814" y="1661" width="78" height="70"/>
 22     <SubTexture name="carrots.png" x="812" y="554" width="54" height="49"/>
 23     <SubTexture name="cloud.png" x="0" y="1152" width="260" height="134"/>
 24     <SubTexture name="coin_bronze.png" x="329" y="1390" width="60" height="61"/>
 25     <SubTexture name="coin_gold.png" x="244" y="1981" width="61" height="61"/>
 26     <SubTexture name="coin_silver.png" x="307" y="1981" width="61" height="61"/>
 27     <SubTexture name="flame.png" x="900" y="1733" width="41" height="80"/>
 28     <SubTexture name="flyMan_fly.png" x="566" y="510" width="122" height="139"/>
 29     <SubTexture name="flyMan_jump.png" x="568" y="1534" width="122" height="135"/>
 30     <SubTexture name="flyMan_stand.png" x="568" y="1671" width="122" height="139"/>
 31     <SubTexture name="flyMan_still_fly.png" x="692" y="1667" width="120" height="132"/>
 32     <SubTexture name="flyMan_still_jump.png" x="698" y="1801" width="120" height="128"/>
 33     <SubTexture name="flyMan_still_stand.png" x="707" y="0" width="120" height="132"/>
 34     <SubTexture name="gold_1.png" x="698" y="1931" width="84" height="84"/>
 35     <SubTexture name="gold_2.png" x="829" y="0" width="66" height="84"/>
 36     <SubTexture name="gold_3.png" x="897" y="1574" width="50" height="84"/>
 37     <SubTexture name="gold_4.png" x="645" y="651" width="15" height="84"/>
 38     <SubTexture name="grass1.png" x="868" y="1877" width="58" height="57"/>
 39     <SubTexture name="grass2.png" x="784" y="1931" width="82" height="70"/>
 40     <SubTexture name="grass_brown1.png" x="534" y="1063" width="58" height="57"/>
 41     <SubTexture name="grass_brown2.png" x="801" y="752" width="82" height="70"/>
 42     <SubTexture name="ground_cake.png" x="0" y="576" width="380" height="94"/>
 43     <SubTexture name="ground_cake_broken.png" x="0" y="0" width="380" height="94"/>
 44     <SubTexture name="ground_cake_small.png" x="218" y="1456" width="201" height="100"/>
 45     <SubTexture name="ground_cake_small_broken.png" x="262" y="1152" width="200" height="100"/>
 46     <SubTexture name="ground_grass.png" x="0" y="288" width="380" height="94"/>
 47     <SubTexture name="ground_grass_broken.png" x="0" y="384" width="380" height="94"/>
 48     <SubTexture name="ground_grass_small.png" x="213" y="1662" width="201" height="100"/>
 49     <SubTexture name="ground_grass_small_broken.png" x="382" y="204" width="200" height="100"/>
 50     <SubTexture name="ground_sand.png" x="0" y="672" width="380" height="94"/>
 51     <SubTexture name="ground_sand_broken.png" x="0" y="1056" width="380" height="94"/>
 52     <SubTexture name="ground_sand_small.png" x="208" y="1879" width="201" height="100"/>
 53     <SubTexture name="ground_sand_small_broken.png" x="382" y="102" width="200" height="100"/>
 54     <SubTexture name="ground_snow.png" x="0" y="768" width="380" height="94"/>
 55     <SubTexture name="ground_snow_broken.png" x="0" y="480" width="380" height="94"/>
 56     <SubTexture name="ground_snow_small.png" x="213" y="1764" width="201" height="100"/>
 57     <SubTexture name="ground_snow_small_broken.png" x="382" y="306" width="200" height="100"/>
 58     <SubTexture name="ground_stone.png" x="0" y="96" width="380" height="94"/>
 59     <SubTexture name="ground_stone_broken.png" x="0" y="192" width="380" height="94"/>
 60     <SubTexture name="ground_stone_small.png" x="382" y="408" width="200" height="100"/>
 61     <SubTexture name="ground_stone_small_broken.png" x="232" y="1288" width="200" height="100"/>
 62     <SubTexture name="ground_wood.png" x="0" y="960" width="380" height="94"/>
 63     <SubTexture name="ground_wood_broken.png" x="0" y="864" width="380" height="94"/>
 64     <SubTexture name="ground_wood_small.png" x="218" y="1558" width="200" height="100"/>
 65     <SubTexture name="ground_wood_small_broken.png" x="382" y="0" width="200" height="100"/>
 66     <SubTexture name="jetpack.png" x="563" y="1843" width="133" height="160"/>
 67     <SubTexture name="jetpack_item.png" x="852" y="1089" width="65" height="77"/>
 68     <SubTexture name="lifes.png" x="868" y="1936" width="52" height="71"/>
 69     <SubTexture name="lighting_blue.png" x="895" y="453" width="55" height="114"/>
 70     <SubTexture name="lighting_yellow.png" x="897" y="0" width="55" height="114"/>
 71     <SubTexture name="mushroom_brown.png" x="814" y="1574" width="81" height="85"/>
 72     <SubTexture name="mushroom_red.png" x="812" y="453" width="81" height="99"/>
 73     <SubTexture name="particle_beige.png" x="563" y="2005" width="58" height="41"/>
 74     <SubTexture name="particle_blue.png" x="852" y="1168" width="51" height="49"/>
 75     <SubTexture name="particle_brown.png" x="820" y="1877" width="44" height="48"/>
 76     <SubTexture name="particle_darkBrown.png" x="784" y="2003" width="54" height="43"/>
 77     <SubTexture name="particle_darkGrey.png" x="826" y="1364" width="51" height="43"/>
 78     <SubTexture name="particle_green.png" x="800" y="1003" width="48" height="46"/>
 79     <SubTexture name="particle_grey.png" x="623" y="2005" width="38" height="41"/>
 80     <SubTexture name="particle_pink.png" x="829" y="86" width="53" height="46"/>
 81     <SubTexture name="portal_orange.png" x="0" y="1288" width="230" height="82"/>
 82     <SubTexture name="portal_orangeParticle.png" x="262" y="1254" width="20" height="20"/>
 83     <SubTexture name="portal_yellow.png" x="0" y="1372" width="230" height="82"/>
 84     <SubTexture name="portal_yellowParticle.png" x="284" y="1254" width="20" height="20"/>
 85     <SubTexture name="powerup_bubble.png" x="826" y="134" width="71" height="70"/>
 86     <SubTexture name="powerup_bunny.png" x="826" y="1220" width="71" height="70"/>
 87     <SubTexture name="powerup_empty.png" x="894" y="1661" width="71" height="70"/>
 88     <SubTexture name="powerup_jetpack.png" x="820" y="1805" width="71" height="70"/>
 89     <SubTexture name="powerup_wings.png" x="826" y="1292" width="71" height="70"/>
 90     <SubTexture name="silver_1.png" x="584" y="406" width="84" height="84"/>
 91     <SubTexture name="silver_2.png" x="852" y="1003" width="66" height="84"/>
 92     <SubTexture name="silver_3.png" x="899" y="1219" width="50" height="84"/>
 93     <SubTexture name="silver_4.png" x="662" y="651" width="14" height="84"/>
 94     <SubTexture name="smoke.png" x="879" y="1364" width="51" height="48"/>
 95     <SubTexture name="spikeBall1.png" x="534" y="763" width="142" height="148"/>
 96     <SubTexture name="spikeBall_2.png" x="464" y="1122" width="148" height="141"/>
 97     <SubTexture name="spikeMan_jump.png" x="736" y="1063" width="114" height="155"/>
 98     <SubTexture name="spikeMan_stand.png" x="814" y="1417" width="90" height="155"/>
 99     <SubTexture name="spikeMan_walk1.png" x="704" y="1256" width="120" height="159"/>
100     <SubTexture name="spikeMan_walk2.png" x="812" y="296" width="90" height="155"/>
101     <SubTexture name="spike_bottom.png" x="894" y="206" width="51" height="87"/>
102     <SubTexture name="spike_top.png" x="885" y="752" width="51" height="87"/>
103     <SubTexture name="spikes_bottom.png" x="147" y="1988" width="95" height="53"/>
104     <SubTexture name="spikes_top.png" x="232" y="1390" width="95" height="53"/>
105     <SubTexture name="spring.png" x="420" y="1558" width="145" height="77"/>
106     <SubTexture name="springMan_hurt.png" x="800" y="860" width="110" height="141"/>
107     <SubTexture name="springMan_stand.png" x="801" y="609" width="110" height="141"/>
108     <SubTexture name="spring_in.png" x="0" y="1988" width="145" height="57"/>
109     <SubTexture name="spring_out.png" x="434" y="1265" width="145" height="110"/>
110     <SubTexture name="sun1.png" x="534" y="913" width="142" height="148"/>
111     <SubTexture name="sun2.png" x="421" y="1390" width="148" height="142"/>
112     <SubTexture name="wingMan1.png" x="382" y="635" width="174" height="126"/>
113     <SubTexture name="wingMan2.png" x="0" y="1879" width="206" height="107"/>
114     <SubTexture name="wingMan3.png" x="0" y="1559" width="216" height="101"/>
115     <SubTexture name="wingMan4.png" x="0" y="1456" width="216" height="101"/>
116     <SubTexture name="wingMan5.png" x="382" y="510" width="182" height="123"/>
117     <SubTexture name="wing_left.png" x="558" y="651" width="85" height="74"/>
118     <SubTexture name="wing_right.png" x="571" y="1458" width="85" height="74"/>
119 </TextureAtlas>
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上面这张图+这份xml,在pygame中我们称为spritesheet,通过xml中的name,找到对应的坐标、尺寸信息,就能取出指定的小图片,先研究下如何用python解析xml:

 1 from os import path
 2 from xml.dom.minidom import parse
 3 
 4 xml_file_path = path.join(path.dirname(__file__), "../img/spritesheet_jumper.xml")
 5 print(xml_file_path)
 6 
 7 dom_tree = parse(xml_file_path)
 8 root_textures = dom_tree.documentElement
 9 sub_textures = root_textures.getElementsByTagName("SubTexture")
10 
11 for texture in sub_textures:
12     print("name:", texture.getAttribute("name"), ",x:",
13           texture.getAttribute("x"), ",y:", texture.getAttribute("y"),
14           ",width:", texture.getAttribute("width"), ",height:", texture.getAttribute("height"))
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注:相对目录结构,参考下图:

上面这几行代码,就能把xml解析出来,输出类似下面这样:

...
name: bronze_1.png ,x: 707 ,y: 296 ,width: 84 ,height: 84
name: bronze_2.png ,x: 826 ,y: 206 ,width: 66 ,height: 84
name: bronze_3.png ,x: 899 ,y: 116 ,width: 50 ,height: 84
name: bronze_4.png ,x: 670 ,y: 406 ,width: 14 ,height: 84
...

知道了xml如何解析,下面就是如何取出指定小图片,借助pygame的最小框架,做一个测试:

 1 import pygame
 2 from os import path
 3 from xml.dom.minidom import parse
 4 
 5 # 游戏中的一些常量定义
 6 SIZE = (WIDTH, HEIGHT) = (380, 380)
 7 FPS = 10
 8 
 9 # 颜色常量定义
10 BLACK = 0, 0, 0
11 WHITE = 255, 255, 255
12 
13 # 初始化
14 pygame.init()
15 pygame.mixer.init()
16 
17 # 窗口、标题等初始化
18 screen = pygame.display.set_mode(SIZE)
19 pygame.display.set_caption("My Game")
20 clock = pygame.time.Clock()
21 
22 spritesheet_image_file_name = path.join(path.dirname(__file__), "../img/spritesheet_jumper.png")
23 spritesheet_xml_file_name = path.join(path.dirname(__file__), "../img/spritesheet_jumper.xml")
24 spritesheet_image = pygame.image.load(spritesheet_image_file_name)
25 spritesheet_image.set_colorkey(BLACK)
26 spritesheet_dom_tree = parse(spritesheet_xml_file_name)
27 root_textures = spritesheet_dom_tree.documentElement
28 sub_textures = root_textures.getElementsByTagName("SubTexture")
29 dic_image = {}
30 
31 
32 # 解析xml,找出指定图片的坐标、尺寸信息
33 def get_image_rect(img_name):
34     if dic_image.get(img_name):
35         return dic_image[img_name]
36     for texture in sub_textures:
37         name = texture.getAttribute("name")
38         if img_name == name:
39             dic_image[img_name] = pygame.Rect(
40                 int(texture.getAttribute("x")),
41                 int(texture.getAttribute("y")),
42                 int(texture.getAttribute("width")),
43                 int(texture.getAttribute("height"))
44             )
45             return dic_image[img_name]
46 
47 
48 # 获取指定图片的Surface对象,同时支持旋转+缩放
49 def get_image(img_name, angle=0, scale=1.0):
50     rect = get_image_rect(img_name);
51     image = pygame.Surface((rect.width, rect.height))
52     image.blit(spritesheet_image, (0, 0), rect)
53     image.set_colorkey(BLACK)
54     new_image = pygame.transform.rotozoom(image, angle, scale)
55     new_image.set_colorkey(BLACK)
56     return new_image
57 
58 
59 # 循环入口
60 running = True
61 while running:
62 
63     # 设置帧数
64     clock.tick(FPS)
65 
66     # 事件处理
67     for event in pygame.event.get():
68         # 退出处理
69         if event.type == pygame.QUIT:
70             running = False
71 
72     # (update) 游戏更新逻辑(比如:改动角色的位置或一些重要变量等,这里仅演示更新当前时间)
73     image1 = get_image("bunny1_hurt.png", 0, 0.5)
74     image2 = get_image("bunny1_walk1.png", 45, 0.5)
75     image3 = get_image("bunny2_stand.png", -45, 0.5)
76 
77     # (draw)渲染屏幕
78     screen.fill(BLACK)  # 先准备一块黑布
79     screen.blit(image1, (0, 0), image1.get_rect())
80     screen.blit(image2, (200, 200), image2.get_rect())
81     screen.blit(image3, (200, 50), image3.get_rect())
82 
83     # 屏幕内容刷新
84     pygame.display.update()
85 
86 # 循环结束后,退出游戏
87 pygame.quit()
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运行效果如下:

好了,前戏足够了,回到jumpy的游戏中来,在sprites.py中,新建一个类:

 1 class Spritesheet:
 2     def __init__(self, png_file_name, xml_file_name):
 3         self.sprite_sheet = pg.image.load(png_file_name)
 4         self.sprite_sheet_dom_tree = parse(xml_file_name)
 5         self.dic_image = {}
 6         self.root_textures = self.sprite_sheet_dom_tree.documentElement
 7         self.sub_textures = self.root_textures.getElementsByTagName("SubTexture")
 8 
 9     def get_image_rect(self, img_name):
10         if self.dic_image.get(img_name):
11             return self.dic_image[img_name]
12         for texture in self.sub_textures:
13             name = texture.getAttribute("name")
14             if img_name == name:
15                 self.dic_image[img_name] = pg.Rect(
16                     int(texture.getAttribute("x")),
17                     int(texture.getAttribute("y")),
18                     int(texture.getAttribute("width")),
19                     int(texture.getAttribute("height"))
20                 )
21                 return self.dic_image[img_name]
22 
23     def get_image(self, img_name):
24         rect = self.get_image_rect(img_name)
25         image = pg.Surface((rect.width, rect.height))
26         image.blit(self.sprite_sheet, (0, 0), rect)
27         image = pg.transform.scale(image, (rect.width // 3, rect.height // 3))
28         image.set_colorkey(BLACK, 1)
29         return image
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同时原有的Player.py类,初始化时,image换成加载图片(终于可以换掉单调的小方块了)

class Player(pg.sprite.Sprite):
    def __init__(self, game):
        ...
        self.image = self.game.spritesheet.get_image("bunny1_stand.png")
        self.rect = self.image.get_rect()
        ...

最后看看main.py这个主类,还记得上一回,为了加载历史最高得分,新增了一个load_data函数吗?现在又用到了它了:

1     def load_data(self):
2         # 加载历史最高分
3         ...
4         # load spritesheet
5         self.spritesheet = Spritesheet(path.join(self.dir, "../img/spritesheet_jumper.png"),
6                                        path.join(self.dir, "../img/spritesheet_jumper.xml"))
View Code

源码:https://github.com/yjmyzz/kids-can-code/tree/master/part_09

posted @ 2019-02-17 16:01 菩提树下的杨过 阅读(...) 评论(...) 编辑 收藏