Python笔记：利用pygame模块实现三原色颜色滚动条效果

叁歲伎倆 2021-12-24 00:31 106阅读 0赞

import pygame
    from pygame.locals import *
    from sys import exit
    def create_scales(height):#用于创建指定大小的图像对象实例，分别表示红，绿，蓝三块区域,主动实例化三个Surface对象
        red_scale_surface=pygame.surface.Surface((SCREEN_WIDTH,height))#与窗口Surface等宽，高度自行调整，下同
        green_scale_surface=pygame.surface.Surface((SCREEN_WIDTH,height))
        blue_scale_surface=pygame.surface.Surface((SCREEN_WIDTH,height))
        for x in range(640):
            c=int((x/640)*255)#每个x轴部分占RGB颜色的多少，等同x*(255/640)
            red=(c,0,0)
            green=(0,c,0)
            blue=(0,0,c)
            line_rect=Rect(x,0,1,height)
            pygame.draw.rect(red_scale_surface,red,line_rect)
            pygame.draw.rect(green_scale_surface,green,line_rect)
            pygame.draw.rect(blue_scale_surface,blue,line_rect)
        return red_scale_surface,green_scale_surface,blue_scale_surface
    def main():
        pygame.init()#初始化pygame以及相关模块
        screen=pygame.display.set_mode((SCREEN_WIDTH,SCREEN_HEIGHT),0,32)#返回一个窗口Surface对象
        red_scale, green_scale, blue_scale = create_scales(80)
        color=[127,127,127]#初始化为灰色
        while True:
            for event in pygame.event.get():
                if event.type==QUIT:
                    pygame.quit()
                    exit()
            screen.fill((0,0,0))#使用纯颜色填充窗口Surface对象
            screen.blit(red_scale,(0,00))#将红色Surface对象绘制到窗口Surface对象上
            screen.blit(green_scale,(0,80))#将绿色Surface对象绘制到窗口Surface对象上
            screen.blit(blue_scale,(0,160))#将蓝色Surface对象绘制到窗口Surface对象上
            x,y=pygame.mouse.get_pos()#获取鼠标在窗口中的位置
            
            if pygame.mouse.get_pressed()[0]:#获取鼠标按钮状态,get_pressed()[0]为左键是否为按下状态
                for component in range(3):
                    if y > component*80 and y < (component+1)*80:#判断是在哪个Surface对象(red_scale,green_scale,blue_scale)上移动鼠标
                        color[component] = int((x/639)*255)#操作color列表，component为索引值
                pygame.display.set_caption("PyGame Color Test - "+str(tuple(color)))#在窗口标题上显示RGB颜色元组
            
            for component in range(3):
                pos = ( int((color[component]/255)*639), component*80+40 )
                pygame.draw.circle(screen, (255, 255, 255), pos, 20)#绘制白色圆点.pos圆心坐标，20为圆半径大小
     
            pygame.draw.rect(screen, tuple(color), Rect(0, 240, SCREEN_WIDTH, SCREEN_HEIGHT))#绘制最下面的显示区域，由于上方的if语句不停的改变color列表的数值，死循环中该行语句一直在不停的执行画不同颜色矩形
     
            pygame.display.update()#不断刷新画面
        
    if __name__=="__main__":
        #设置非全屏模式下窗口分辨率
        SCREEN_WIDTH = 640
        SCREEN_HEIGHT = 480
        main()

输出:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjEyNDIzNA_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjEyNDIzNA_size_16_color_FFFFFF_t_70]: /images/20211223/92ac17f25d3849d28f53d300c56834c5.png