#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>

#define WINDSIZEX 100
#define WINDSIZEY 100

void
init (void)
{
    int i;
    GLfloat white[] = { 1.0, 1.0, 1.0, 1.0 };

    glClearColor (0.0, 0.0, 0.0, 1.0);
    glColor4fv (white);
    glDisable (GL_DITHER);

    // Check if GL_EXT_framebuffer_object is supported
    if (!strstr (glGetString (GL_EXTENSIONS), "GL_EXT_framebuffer_object"))
    {
        printf ("GL_EXT_framebuffer_object is not supported\n");
        exit(0);
    }
    else
    {
        printf ("GL_EXT_framebuffer_object is supported\n");
    }
}


static void
test (void)
{
    GLuint fb_binding;

    glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, (GLint *) & fb_binding);
    printf("fb_binding = %d\n", fb_binding);
}

void
display (void)
{
    glMatrixMode (GL_PROJECTION);
    glLoadIdentity ();
    gluOrtho2D (0, WINDSIZEX, 0, WINDSIZEX);
    test ();
}

int
main (int argc, char **argv)
{
    glutInit (&argc, argv);
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGBA);
    glutInitWindowSize (WINDSIZEX, WINDSIZEY);
    glutInitWindowPosition (100, 100);
    glutCreateWindow (argv[0]);
    init ();
    glutDisplayFunc (display);
    glutMainLoop ();
    return 0;

}