Lighting!




My light position variable is declared as:
  GLfloat light[4];

Remember:
 graph.light[3] = 1; //0 for directional 1 for positional


So all that's left to do is
Turn it on, enable which lights you want on. Set some options (per light)

  glLightfv(GL_LIGHT0, GL_POSITION, graph.light);
  glShadeModel(GL_SMOOTH); //gl_smooth is phong-ish //gl_flat is gouraud-ish
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, 2.0);

// atten factor is 1/(c  + l*d + q*d^2)

If you want some spotlight options:
  GLfloat spot_direction[] = { 0.0, 0.0, -1.0 };

  glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, 45.0);//half cone
  glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, spot_direction); 
  glLightf(GL_LIGHT0, GL_SPOT_EXPONENT, 2.0);
//compare v dot d to cosine (cutoff)
Math at bottom of:
http://www.glprogramming.com/red/chapter05.html





Generally you'll want your objects to have some material properties.
(May consider colormaterial later on)
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT,GL_AMBIENT_AND_DIFFUSE);


  GLfloat copdif[] = {.7038, .27048, .0828, 1.0};
  GLfloat copspec[] = {.256777, .137622, .086014, 1.0};
  GLfloat copshini[] = { 12.8 };

  glMaterialfv(GL_FRONT, GL_DIFFUSE, copdif);
  glMaterialfv(GL_FRONT, GL_SPECULAR, copspec);
  glMaterialfv(GL_FRONT, GL_SHININESS, copshini);