84.提高游戏的颜值3

import pygame
import sys        # 退出需要
from pygame.locals import *
pygame.init()     # 初始化
size = width, height = 600, 385  # 设置窗口尺寸
bg = (0, 0, 0)                   # 背景颜色
clock = pygame.time.Clock()      # 设置帧率需要
screen = pygame.display.set_mode(size)      # 设置窗口
pygame.display.set_caption("Python Demo")   # 设置窗口名
turtle = pygame.image.load("18.gif").convert_alpha()
# .convert可尽可能高效的处理图片
background = pygame.image.load("17.png").convert()
position = turtle.get_rect()  # 获取乌龟位置
position.center = width // 2, height // 2  # 获取乌龟中心位置
#############################################################
def blit_alpha(target, source, location, opacity):
    x = location[0]
    y = location[1]
    temp = pygame.Surface((source.get_width(), source.get_height())).convert()
    temp.blit(target, (-x, -y))
    temp.blit(source, (0, 0))
    temp.set_alpha(opacity)
    target.blit(temp, location)
#############################################################
while True:
    for event in pygame.event.get():
        if event.type == QUIT:
            sys.exit()
    screen.blit(background, (0, 0))
    ############################################################
    # screen.blit(turtle, position)
    blit_alpha(screen, turtle, position, 200)
    ############################################################
    pygame.display.flip()
    clock.tick(30)