linux - 使用 OpenGL 和 Freeglut 在 Linux 中显示 RGB 窗口

Question

我想创建一个覆盖整个桌面屏幕的窗口，显示颜色为 RGB，然后是 VIBGYOR。颜色延迟应为 1 秒。 这是我编写的代码，但输出不符合预期。谁能告诉我哪里错了？

#include<GL/freeglut.h>
#include<GL/glut.h>
#include<stdio.h>

void main(int argc, char **argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH );

    glutInitWindowSize(1280,1024);
    glutCreateWindow("Displays");
    glutFullScreen();   

    glClearColor (1.0, 0.0, 0.0, 0.0);      //Red
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(0,1,0,0);              //Green
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(0,0,1,0);
    glClear(GL_COLOR_BUFFER_BIT);           //Blue
    sleep(1);   

    glClearColor(0.933, 0.510, 0.933, 0.0);     //violet
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(0.294, 0.000, 0.510, 1);       //Indigo
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(0,0,1,1);              //Blue
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(0,0.502,0,1);          //Green
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(1,1,0,1);              //Yellow
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(1,0.647,0,1);          //Orange
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

    glClearColor(1,0,0,1);              //Red
    glClear(GL_COLOR_BUFFER_BIT);
    sleep(1);   

glutMainLoop();
}

谢谢。

Answer 1

您正在使用 GLUT_DOUBLE ( double buffering ) 初始化显示模式，您需要在每次完成缓冲区工作时添加 gluSwapBuffers() 并且想要显示它。

...
glClearColor(1,0,0,1);              //Red
glClear(GL_COLOR_BUFFER_BIT);
glutSwapBuffers();
sleep(1);   
...

Difference between single buffered(GLUT_SINGLE) and double buffered drawing(GLUT_DOUBLE)

When using GL_SINGLE, you can picture your code drawing directly to the display.

When using GL_DOUBLE, you can picture having two buffers. One of them is always visible, the other one is not

glut examples

nehe's legacy tutorials

What is the nicest way to close GLUT

void glutLeaveMainLoop ( void );