【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）】

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 > 
        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)

========================================================

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()

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()

 

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 > 
        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)

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 > 
        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)