Someone

static void
draw(CompScreen* s, GLint gear1, GLint gear2, GLint gear3, GLfloat angle)
{
   glPushMatrix();
   
   glTranslatef(0.0f, 0.0f, s->width / 2);
   glScalef(1.0f / s->width, 1.0f / s->height, 1.0f);

   glPushMatrix();
   glTranslatef(-3.0, -2.0, 0.0);
   glRotatef(angle, 0.0, 0.0, 1.0);
   glCallList(gear1);
   glPopMatrix();

   glPushMatrix();
   glTranslatef(3.1, -2.0, 0.0);
   glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
   glCallList(gear2);
   glPopMatrix();

   glPushMatrix();
   glTranslatef(-3.1, 4.2, 0.0);
   glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
   glCallList(gear3);
   glPopMatrix();
   
   glPopMatrix();
}