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【4】【MOOC】Python游戏开发入门-北京理工大学【第三部分-游戏开发之机制（色彩与绘图）】
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学习地址链接：http://www.icourse163.org/course/0809BIT021E-1001873001?utm_campaign=share&utm_medium=androidShare&utm_source=qq
Pygame色彩与绘图机制
1.Pygame色彩机制
色彩表达
pygame.Color
Color类用于表达色彩，使用RGB或RGBA色彩模式，A可选
Color类可以用色彩名字、RGBA值、HTML色彩格式等方式定义
Color(name) 例如：Color("grey")
Color(r,g,b,a) 例如：Color(190, 190, 190, 255)
Color(rgbvalue) 例如：Color("#BEBEBEFF")
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RGB色彩模式
·红绿蓝三个通道颜色组合
·覆盖视力所能感知的所有颜色
·RGB取值范围0-255
RGBA色彩模式
·RGB色彩模式之外增加了第四维度：alpha通道
·alpha通道表示不透明度，取值0-255，默认255
·alpha通道值越大，不透明度越高，255表示不透明
pygame.Color类
pygame.Color.r 获得Color类的红色值r
pygame.Color.g 获得Color类的绿色值g
pygame.Color.b获得Color类的蓝色值b
pygame.Color.normalize将RGBA各通道值归一到0-1之间
壁球小游戏（色彩型）源代码：
import pygame, sys pygame.init()
icon = pygame.image.load("PYG03-flower.png")
pygame.display.set_icon(icon)
size = width, height = 600, 400
speed = [1, 1]
BLACK = 0, 0, 0
screen = pygame.display.set_mode(size, pygame.RESIZABLE)
pygame.display.set_caption("Pygame壁球")
ball = pygame.image.load("PYG02-ball.gif")
ballrect = ball.get_rect()
fps = 300
fclock = pygame.time.Clock()
still = False
bgcolor = pygame.Color("black") def RGBChannel(a):
return 0 if a < 0 else (255 if a > 255 else int(a)) while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
speed[0] = speed[0] if speed[0] == 0 else (abs(speed[0]) - 1) * int(speed[0] / abs(speed[0]))
elif event.key == pygame.K_RIGHT:
speed[0] = speed[0] + 1 if speed[0] > 0 else speed[0] - 1
elif event.key == pygame.K_UP:
speed[1] = speed[1] + 1 if speed[1] > 0 else speed[1] - 1
elif event.key == pygame.K_DOWN:
speed[1] = speed[1] if speed[1] == 0 else (abs(speed[1]) - 1) * int(speed[1] / abs(speed[1]))
elif event.key == pygame.K_ESCAPE:
sys.exit()
elif event.type == pygame.VIDEORESIZE:
size = width, height = event.size[0], event.size[1]
screen = pygame.display.set_mode(size, pygame.RESIZABLE)
elif event.type == pygame.MOUSEBUTTONDOWN:
if event.button == 1:
still = True
elif event.type == pygame.MOUSEBUTTONUP:
still = False
if event.button == 1:
ballrect = ballrect.move(event.pos[0] - ballrect.left, event.pos[1] - ballrect.top)
elif event.type == pygame.MOUSEMOTION:
if event.buttons[0] == 1:
ballrect = ballrect.move(event.pos[0] - ballrect.left, event.pos[1] - ballrect.top)
if pygame.display.get_active() and not still:
ballrect = ballrect.move(speed[0], speed[1])
if ballrect.left < 0 or ballrect.right > width:
speed[0] = - speed[0]
if ballrect.right > width and ballrect.right + speed[0] > ballrect.right:
speed[0] = - speed[0]
if ballrect.top < 0 or ballrect.bottom > height:
speed[1] = - speed[1]
if ballrect.bottom > height and ballrect.bottom + speed[1] > ballrect.bottom:
speed[1] = - speed[1] bgcolor.r = RGBChannel(ballrect.left * 255 / width)
bgcolor.g = RGBChannel(ballrect.top * 255 / height)
bgcolor.b = RGBChannel(min(speed[0], speed[1]) * 255 / max(speed[0], speed[1], 1)) screen.fill(bgcolor)
screen.blit(ball, ballrect)
pygame.display.update()
fclock.tick(fps)
壁球小游戏（色彩型）
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2.Pygame图形绘制机制
图形绘制
pygame.draw
向屏幕上绘制一些简单的图形，如直线、圆形、椭圆等任何一个圆形绘制后，会返回一个矩形Rect类表示该形状。
Rect类
pygame.Rect
表达一个矩形区域的类，用于存储坐标和长度信息
Pygame利用Rect类来操作图形/图像等元素
四个参数：left,top,width,height
图像绘制练习源代码：
import pygame, sys
from math import pi pygame.init()
screen = pygame.display.set_mode((600, 400))
pygame.display.set_caption("Pygame图形绘制")
GOLD = 255, 251, 0
RED = pygame.Color('red')
WHITE = 255, 255, 255
GREEN = pygame.Color('green') # r1rect = pygame.draw.rect(screen, GOLD, (100,100,200,100), 5)
# r2rect = pygame.draw.rect(screen, RED, (210,210,200,100), 0) e1rect = pygame.draw.ellipse(screen, GREEN, (50, 50, 500, 300), 3)
c1rect = pygame.draw.circle(screen, GOLD, (200, 180), 30, 5)
c2rect = pygame.draw.circle(screen, GOLD, (400, 180), 30)
r1rect = pygame.draw.rect(screen, RED, (170, 130, 60, 10), 3)
r2rect = pygame.draw.rect(screen, RED, (370, 130, 60, 10))
plist = [(295, 170), (285, 250), (260, 280), (340, 280), (315, 250), (305, 170)]
l1rect = pygame.draw.lines(screen, GOLD, True, plist, 2)
a1rect = pygame.draw.arc(screen, RED, (200, 220, 200, 100), 1.4 * pi, 1.9 * pi, 3) while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
pygame.display.update()
Pygame图形绘制
结果显示：
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3.Pygame文字绘制机制
Rect返回一个Rect对象
练习，打印文字：世界和平
源代码：
import pygame, sys
import pygame.freetype pygame.init()
screen = pygame.display.set_mode((600, 400))
pygame.display.set_caption("Pygame文字绘制")
GOLD = 255, 251, 0 f1 = pygame.freetype.Font("C://Windows//Fonts//msyh.ttc", 36)
f1rect = f1.render_to(screen, (200, 160), "世界和平", fgcolor=GOLD, size=50) while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
pygame.display.update()
Pygame文字绘制
返回一个元组，包含Surface对象和Rect对象
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4.Pygame绘图机制原理精髓
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5.壁球小游戏(文字型)
需求：
把壁球改为一段文字，可以进行移动
从需求到实现的关键要素：
·文字移动：文字的移动绘制及刷新
使用.render_to()方法：
# 使用.render_to()方法： import pygame, sys
import pygame.freetype pygame.init()
size = width, height = 600, 400
speed = [1, 1]
GOLD = 255, 251, 0
BLACK = 0, 0, 0
pos = [230, 160]
screen = pygame.display.set_mode(size)
pygame.display.set_caption("Pygame文字绘制")
f1 = pygame.freetype.Font("C://Windows//Fonts//msyh.ttc", 36)
f1rect = f1.render_to(screen, pos, "世界和平", fgcolor=GOLD, size=50)
fps = 300
fclock = pygame.time.Clock() while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
if pos[0] < 0 or pos[0] + f1rect.width > width:
speed[0] = - speed[0]
if pos[1] < 0 or pos[1] + f1rect.height > height:
speed[1] = - speed[1]
pos[0] = pos[0] + speed[0]
pos[1] = pos[1] + speed[1] screen.fill(BLACK)
f1rect = f1.render_to(screen, pos, "世界和平", fgcolor=GOLD, size=50)
pygame.display.update()
fclock.tick(fps)
壁球小游戏（文字型）
使用.render()方法：
# 使用.render()方法： import pygame, sys
import pygame.freetype pygame.init()
size = width, height = 600, 400
speed = [1, 1]
GOLD = 255, 251, 0
BLACK = 0, 0, 0
pos = [230, 160]
screen = pygame.display.set_mode(size)
pygame.display.set_caption("Pygame文字绘制")
f1 = pygame.freetype.Font("C://Windows//Fonts//msyh.ttc", 36)
f1surf, f1rect = f1.render("世界和平", fgcolor=GOLD, size=50)
fps = 300
fclock = pygame.time.Clock() while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
if pos[0] < 0 or pos[0] + f1rect.width > width:
speed[0] = - speed[0]
if pos[1] < 0 or pos[1] + f1rect.height > height:
speed[1] = - speed[1]
pos[0] = pos[0] + speed[0]
pos[1] = pos[1] + speed[1] screen.fill(BLACK)
f1surf, f1rect = f1.render("世界和平", fgcolor=GOLD, size=50)
screen.blit(f1surf, (pos[0], pos[1]))
pygame.display.update()
fclock.tick(fps)
壁球小游戏（文字型）
