/* 
   This is a function which initializes lighting in an 
   OpenGL program. I can be called from an init function
   which also sets up projection, depth buffering, etc.
   For lighting to work properly there should be a normal
   vector supplied for every vertex.
*/


void initLighting(void) {
  GLfloat mat_properties[] = {0.5, 0.5, 0.5, 1.0};
  GLfloat white_light[] = {1.0, 1.0, 1.0, 1.0};
  GLfloat light_position[] = {1.0, 1.0, 2.0, 0.0 };

  glShadeModel(GL_SMOOTH);

  glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, white_light);
  glLightfv(GL_LIGHT0, GL_AMBIENT, white_light);

  /* object color determined here */
  glMaterialfv(GL_FRONT, GL_AMBIENT, mat_properties);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_properties);

  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
}