Question

当我编译它时，它会产生一个空白的blac屏幕，如果我从任一位置取出过量交换缓冲区，或者两者同时我得到一个空白的白色屏幕，那么问题是什么？

#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>



 void ProcessSpecialKeys(int key, int x, int y){

    switch(key){

       case GLUT_KEY_RIGHT:

exit(0);

       case GLUT_KEY_LEFT:

exit(0);

       case GLUT_KEY_UP:

exit(0);

       case GLUT_KEY_DOWN:

exit(0);

       default:

exit(0);

    }

}




void renderPrimitive(void){

    glBegin(GL_QUADS);
    glVertex3f(-1.0f,-1.0f,0.0f);
    glVertex3f(-1.0f,1.0f,0.0f);
    glVertex3f(1.0f,1.0f,0.0f);
    glVertex3f(1.0f,-1.0f,0.0f);
    glEnd();
}

void display(void){

    glTranslatef(0.0f,0.0f,-0.5f);
    renderPrimitive();
    glutSwapBuffers();
}

int main(int argc, char **argv) {

glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(100,100);
glutInitWindowSize(320,320);
glutCreateWindow("Dimension");
glutDisplayFunc(display);

    glLoadIdentity();

    glutSpecialFunc(ProcessSpecialKeys);

glutMainLoop();

return 0;
}

Answer 1

在开始新抽奖之前，您需要清除缓冲区。换句话说，在显示功能中执行此操作：

void display(void){
    glClear(GL_COLOR_BUFFER_BIT); // <-----
    glTranslatef(0.0f,0.0f,-0.5f);
    renderPrimitive();
    glutSwapBuffers();
}

并阅读有关函数glClearColor

的内容

<强> EDITED ：

这不是正确的地方，但要更改背景颜色，请执行以下操作：

void display(void){
    glClearColor(0.5, 0.5, 0.5, 1);
    glClear(GL_COLOR_BUFFER_BIT); // <-----
    glScalef(0.5f,0.5f,0.5f);  // Your Quad is taking all the framebuffer
    renderPrimitive();
    glutSwapBuffers();
}

Answer 2

尝试glColor3f（0.5f，0.5f，0.5f）;并删除glClearColor（0.5,0.5,0.5,1）;

Answer 3

试试这个：

#include <GL/glut.h>
#include <stdlib.h>

void ProcessSpecialKeys(int key, int x, int y)
{
    switch(key)
    {
    case GLUT_KEY_RIGHT:
    case GLUT_KEY_LEFT:
    case GLUT_KEY_UP:
    case GLUT_KEY_DOWN:
        exit(0);
        break;
    default:
        exit(0);
        break;
    }
}

void renderPrimitive()
{
    glBegin(GL_QUADS);
    glVertex3f(-1.0f,-1.0f,0.0f);
    glVertex3f(-1.0f,1.0f,0.0f);
    glVertex3f(1.0f,1.0f,0.0f);
    glVertex3f(1.0f,-1.0f,0.0f);
    glEnd();
}

void display()
{
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    glOrtho( -2, 2, -2, 2, -1, 1 );

    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();

    glPushMatrix();
    glTranslatef(0.0f,0.0f,-0.5f);
    renderPrimitive();
    glPopMatrix();

    glutSwapBuffers();
}

int main(int argc, char **argv) 
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
    glutInitWindowPosition(100,100);
    glutInitWindowSize(320,320);
    glutCreateWindow("Dimension");
    glutDisplayFunc(display);
    glutSpecialFunc(ProcessSpecialKeys);
    glutMainLoop();
    return 0;
}

这只是显示一个空白的黑屏，如果我没有在两个地方放置glutSwapBuffers（），它会显示一个空白的白色屏幕？

3 个答案: