#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>

float r = 0.0;

void init(void)
{
    glClearColor (0.0, 0.0, 0.0, 0.0);
    glShadeModel (GL_FLAT);
}

void idle(void)
{
    r += 0.02;
    glutPostRedisplay();
}

void drawcubes(int level, double size)
{
    glutWireCube(size);
    if (!level)
        return;
    double a = 0.0;
    int i;
    for (i = 0; i < 4; i++)
    {
        glPushMatrix();
            glRotatef(a, 0.0, 1.0, 0.0);
            glTranslatef(size * 0.375, size * 0.625, size * 0.375);
            glRotatef(r, 0.0, 1.0, 0.0);
            drawcubes(level - 1, size * 0.25);
        glPopMatrix();
        a += 90.0;
    }
}

void display(void)
{
    glClear (GL_COLOR_BUFFER_BIT);
    glColor3f (1.0, 1.0, 1.0);
    glLoadIdentity ();             /* clear the matrix */
        /* viewing transformation  */
    glTranslatef(0.0, -1.0, -5.0);
    glRotatef(40.0, 1.0, 0.0, 0.0);
    glRotatef(r, 0.0, 1.0, 0.0);

    drawcubes(4, 2.0);

    glFlush ();
    glutSwapBuffers();
}

void reshape (int w, int h)
{
    glViewport (0, 0, (GLsizei) w, (GLsizei) h);
    glMatrixMode (GL_PROJECTION);
    glLoadIdentity ();
    gluPerspective(60.0, 4.0/3.0, 1.5, 20.0);
    glMatrixMode (GL_MODELVIEW);
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowSize (800, 600);
    glutInitWindowPosition (-1, -1);
    glutCreateWindow (argv[0]);
    init ();
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutIdleFunc(idle);
    glutMainLoop();
    return 0;
}