Two spinning OpenGl Cubes.

DoubleBoxSpinSpaceNormals.c

#include <stdlib.h>
#include <gl/freeglut.h>
 
GLfloat angle = 0.0;

void cube(void) {

	 //front
   glColor3f(1.0,0.0,0.0);
 
   glBegin(GL_POLYGON);
	 glNormal3f(0.0f, 0.0f, 1.0f);
     glVertex3f(0.5f,0.5f,0.5f);
     glVertex3f(-0.5f,0.5f,0.5f);
     glVertex3f(-0.5f,-0.5f,0.5f);
     glVertex3f(0.5f,-0.5f,0.5f);
   glEnd();
   //right

   glColor3f(0.0,1.0,0.0);
   glBegin(GL_POLYGON);
	 glNormal3f(1.0f, 0.0f, 0.0f);
     glVertex3f(0.5,0.5,0.5);
     glVertex3f(0.5,-0.5,0.5);
     glVertex3f(0.5,-0.5,-0.5);
     glVertex3f(0.5,0.5,-0.5);
   glEnd();
   //back
   glColor3f(0.0,1.0,1.0);
   glBegin(GL_POLYGON);
	glNormal3f(0.0f, 0.0f, -1.0f);
     glVertex3f(0.5,0.5,-0.5);
     glVertex3f(0.5,-0.5,-0.5);
     glVertex3f(-0.5,-0.5,-0.5);
     glVertex3f(-0.5,0.5,-0.5);
   glEnd();
   //left
   glColor3f(1.0,0.0,1.0);
   glBegin(GL_POLYGON);
	 glNormal3f(-1.0f, 0.0f, 0.0f);
     glVertex3f(-0.5,0.5,0.5);
     glVertex3f(-0.5,0.5,-0.5);
     glVertex3f(-0.5,-0.5,-0.5);
     glVertex3f(-0.5,-0.5,0.5);
   glEnd();
   //top
   glColor3f(0.0,0.0,1.0);
   glBegin(GL_POLYGON);
	 glNormal3f(0.0f, 1.0f, 0.0f);
     glVertex3f(0.5,0.5,0.5);
     glVertex3f(0.5,0.5,-0.5);
     glVertex3f(-0.5,0.5,-0.5);
     glVertex3f(-0.5,0.5,0.5);
   glEnd();
   //bottom
   glColor3f(1.0,1.0,0.0);
   glBegin(GL_POLYGON);
	 glNormal3f(0.0f, -1.0f, 0.0f);
     glVertex3f(0.5,-0.5,0.5);
     glVertex3f(-0.5,-0.5,0.5);
     glVertex3f(-0.5,-0.5,-0.5);
     glVertex3f(0.5,-0.5,-0.5);
   glEnd();
}

void display(void)
{

   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();



    // set up the camera position
	gluLookAt(0.0, 10.0, -20.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
 
   angle+=0.1f;
   glRotatef(angle, 0.0, 1.0, 0.0);
   cube();
   glTranslatef(2.0f, 0, 0);
   glutSolidCube(1);
   glutSwapBuffers();
}

void init(void)
{
   static GLfloat pos[4] = {5.0, 5.0, 10.0, 0.0};
   glClearColor (0.0, 0.0, 0.0, 0.0);
   glEnable(GL_DEPTH_TEST);
   glShadeModel(GL_FILL);

   glLightfv(GL_LIGHT0, GL_POSITION, pos);
   glEnable(GL_CULL_FACE);
   glEnable(GL_LIGHTING);
   glEnable(GL_LIGHT0);
   glEnable(GL_DEPTH_TEST);
   
}


/* new window size or exposure */
static void reshape(int width, int height)
{
	GLfloat h = (GLfloat) height / (GLfloat) width;
	glViewport(0, 0, (GLint) width, (GLint) height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glFrustum(-1.0, 1.0, -h, h, 5.0, 400.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}


void keyboard(unsigned char key, int x, int y)
{
	x=y;
   switch (key) {
      case 27:
         exit(0);
         break;
	 case 'x':
	 // Modify some variable
	 glutPostRedisplay();
	 break;
   }
}


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

static void idle(void)
{
	glutPostRedisplay();
}


int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH | GLUT_MULTISAMPLE);
   glutInitWindowSize (500, 500);
   glutInitWindowPosition (100, 100);
   glutCreateWindow ("Simple 3-d program");
   init ();
   glutDisplayFunc(display);
   glutIdleFunc(idle);
   glutReshapeFunc(reshape);
   glutKeyboardFunc(keyboard);
   glutMouseFunc(mouse);
   glutMainLoop();
   return 0;
}