OpenGL屏幕外渲染

Question

我有一个应用程序，可以创建一个3D模型并从中导出图像。我用这个例子来做：

#include <windows.h>
#include <GLGL.h>
#include <GLglu.h>
#include <GLglut.h>
#include <opencv2highgui.hpp>

GLfloat light_diffuse[] = { 1.0, 0.0, 0.0, 1.0 };  /* Red diffuse light. */
GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };  /* Infinite light location. */
GLfloat n[6][3] = {  /* Normals for the 6 faces of a cube. */
    { -1.0, 0.0, 0.0 },{ 0.0, 1.0, 0.0 },{ 1.0, 0.0, 0.0 },
    { 0.0, -1.0, 0.0 },{ 0.0, 0.0, 1.0 },{ 0.0, 0.0, -1.0 } };
GLint faces[6][4] = {  /* Vertex indices for the 6 faces of a cube. */
    { 0, 1, 2, 3 },{ 3, 2, 6, 7 },{ 7, 6, 5, 4 },
    { 4, 5, 1, 0 },{ 5, 6, 2, 1 },{ 7, 4, 0, 3 } };
GLfloat v[8][3];  /* Will be filled in with X,Y,Z vertexes. */

void drawBox(void)
{
    int i;

    for (i = 0; i < 6; i++) {
        glBegin(GL_QUADS);
        glNormal3fv(&n[i][0]);
        glVertex3fv(&v[faces[i][0]][0]);
        glVertex3fv(&v[faces[i][1]][0]);
        glVertex3fv(&v[faces[i][2]][0]);
        glVertex3fv(&v[faces[i][3]][0]);
        glEnd();
    }
}

void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    drawBox();
    glFlush();
}

void init(void)
{
    /* Setup cube vertex data. */
    v[0][0] = v[1][0] = v[2][0] = v[3][0] = -1;
    v[4][0] = v[5][0] = v[6][0] = v[7][0] = 1;
    v[0][1] = v[1][1] = v[4][1] = v[5][1] = -1;
    v[2][1] = v[3][1] = v[6][1] = v[7][1] = 1;
    v[0][2] = v[3][2] = v[4][2] = v[7][2] = 1;
    v[1][2] = v[2][2] = v[5][2] = v[6][2] = -1;

    /* Enable a single OpenGL light. */
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glEnable(GL_LIGHT0);
    glEnable(GL_LIGHTING);

    /* Use depth buffering for hidden surface elimination. */
    glEnable(GL_DEPTH_TEST);

    /* Setup the view of the cube. */
    glMatrixMode(GL_PROJECTION);
    gluPerspective( /* field of view in degree */ 40.0,
        /* aspect ratio */ 1.0,
        /* Z near */ 1.0, /* Z far */ 10.0);
    glMatrixMode(GL_MODELVIEW);
    gluLookAt(0.0, 0.0, 5.0,  /* eye is at (0,0,5) */
        0.0, 0.0, 0.0,      /* center is at (0,0,0) */
        0.0, 1.0, 0.);      /* up is in positive Y direction */

                            /* Adjust cube position to be asthetic angle. */
    glTranslatef(0.0, 0.0, -1.0);
    glRotatef(60, 1.0, 0.0, 0.0);
    glRotatef(-20, 0.0, 0.0, 1.0);
}

int main(int argc, char **argv)
{
    int width = 500, height = 500;

    /********* i want to remove this section ************/
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutCreateWindow("red 3D lighted cube");
    /********* i want to remove this section ************/

    init();
    display();

    BYTE* result = new BYTE[3 * width *height];
    glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, result);
    cv::Mat img(width, height, CV_8UC3);
    img.data = result;
    cv::flip(img, img, 0);
    cv::imwrite("D:\result_off.jpg", img);

    return 0;             /* ANSI C requires main to return int. */
}

它运行正确，但是当我运行这个程序时，它会创建一个窗口并显示它然后将其删除。

我试图删除glut *函数并运行我的程序，但它运行时没有导出任何东西。我用谷歌搜索它，发现我应该使用Framebuffer，但我找不到任何例子。

在渲染3D模型时，如何设置程序不显示任何窗口？

注意：我想在Windows和Linux中运行此程序。