Grafika Membuat Dua Planet

#include <GL/glut.h>

static int spin = 0;
static int kanan = 0;
static int kiri = 0;

void init(void)
{
    GLfloat mat_specular[] = { 1.0,1.0, 1.0, 1.0};
    GLfloat mat_shininess[] = {50.0};
    GLfloat light_position[] = {1.0, 1.0, 1.0, 0.0};
    glClearColor (0.1,0.1,0.0,0.0);
    glShadeModel (GL_SMOOTH);

    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);

}
void setViewport(int left, int bottom, int width, int height){
    glViewport(left, bottom, width, height);
}

void display(void)
{
    GLfloat position[] = {0.0, 0.0, 2.0, 0.5};
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();
    glTranslatef(0.0, 0.0, -5.0);

    glPushMatrix();
    glRotated((GLdouble) spin, spin, spin, 0.0);
    glLightfv(GL_LIGHT0,GL_POSITION, position);

    glTranslated(0.0,0.0,1.5);
    glDisable(GL_LIGHTING);

    glColor3f(1.0, 1.0, 0.0);
    glutWireSphere(0.1,50,16);
    glEnable(GL_LIGHTING);
    glPopMatrix();

    glPushMatrix();
    glRotated((GLdouble) spin, spin, spin, 0.0);
    glLightfv(GL_LIGHT0,GL_POSITION, position);
   
    glTranslated(0.0,0.0,1.2);
    glDisable(GL_LIGHTING);
   
    glColor3f(1.0, 1.0, 0.0);
    glutWireSphere(0.1,50,16);

    glEnable(GL_LIGHTING);
    glPopMatrix();
   
    //membuat bumi
    glutSolidSphere (0.5, 100, 32);
   
    glPopMatrix();
    glFlush();
}

void reshape (int w, int h)
{
    glViewport (0,0,(GLsizei) w, (GLsizei) h);
    glMatrixMode ( GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
        glOrtho (-1.5, 1.5, -1.5*(GLfloat)h/(GLfloat)w,
        1.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
    else
        glOrtho (-1.5*(GLfloat)w/(GLfloat)h,
        1.5*(GLfloat)w/(GLfloat)h, -1.5, 1.5, -10.0, 10.0);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
}

void mouse(int button , int state, int x, int y)
{
    switch (button) {
    case GLUT_LEFT_BUTTON :
        if (state ==GLUT_DOWN){
            spin = (spin + 10) % 360;
            glutPostRedisplay();
        }
        break;
    default :
        break;
    }
}

void update(int value){
    glutPostRedisplay();
    glutTimerFunc(10,update,0);
    spin = (spin +1 ) % 360;
    glutPostRedisplay();
}

int main(int argc, char** argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize (700, 500);
    glutInitWindowPosition (100, 100);
    glutCreateWindow (argv[0]);
    init();
    glutTimerFunc(100, update, 0);
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutMouseFunc(mouse);
    glutMainLoop();
    return 0;
}