old update lights

void directionalhdl::shade(vec3f &ambient, vec3f &diffuse, vec3f &specular, vec3f vertex, vec3f normal, float shininess) const
{
	vec3f eye_direction = -vertex;
	float eye_distance = mag(eye_direction);
	eye_direction /= eye_distance;

	vec3f half_vector = norm(direction + eye_direction);

	float normal_dot_light_direction = max(0.0f, dot(normal, direction));
	float normal_dot_half_vector = max(0.0f, dot(normal, half_vector));

	float power_factor = 0.0;
	if (normal_dot_light_direction > 0.0)
		power_factor = pow(normal_dot_half_vector, shininess);

	ambient += this->ambient;
	diffuse += this->diffuse*normal_dot_light_direction;
	specular += this->specular*power_factor;
}

void pointhdl::shade(vec3f &ambient, vec3f &diffuse, vec3f &specular, vec3f vertex, vec3f normal, float shininess) const
{
	vec3f light_direction = position - vertex;
	float light_distance = mag(light_direction);
	light_direction /= light_distance;

	vec3f eye_direction = -vertex;
	float eye_distance = mag(eye_direction);
	eye_direction /= eye_distance;

	float att = 1.0/(attenuation[0] + attenuation[1]*light_distance + attenuation[2]*light_distance*light_distance);

	vec3f half_vector = norm(light_direction + eye_direction);

	float normal_dot_light_direction = max(0.0f, dot(normal, light_direction));
	float normal_dot_half_vector = max(0.0f, dot(normal, half_vector));

	float power_factor = 0.0;
	if (normal_dot_light_direction > 0.0)
		power_factor = pow(normal_dot_half_vector, shininess);

	ambient += this->ambient*att;
	diffuse += this->diffuse*normal_dot_light_direction*att;
	specular += this->specular*power_factor*att;
  }

  void spothdl::shade(vec3f &ambient, vec3f &diffuse, vec3f &specular, vec3f vertex, vec3f normal, float shininess) const
  {
  	vec3f light_direction = position - vertex;
  	float light_distance = mag(light_direction);
  	light_direction /= light_distance;

  	vec3f eye_direction = -vertex;
  	float eye_distance = mag(eye_direction);
  	eye_direction /= eye_distance;

  	float att = 1.0/(attenuation[0] + attenuation[1]*light_distance + attenuation[2]*light_distance*light_distance);
  	float spotdot = dot(-light_direction, direction);

  	float spotatt = 0.0;
  	if (spotdot >= cutoff)
  		spotatt = pow(spotdot, exponent);

  	att *= spotatt;

  	vec3f half_vector = norm(light_direction + norm(-vertex));
  	float normal_dot_light_direction = max(0.0f, dot(normal, light_direction));
  	float normal_dot_half_vector = max(0.0f, dot(normal, half_vector));

  	float power_factor = 0.0;
  	if (normal_dot_light_direction > 0.0)
  		power_factor = pow(normal_dot_half_vector, shininess);

  	ambient += this->ambient*att;
  	diffuse += this->diffuse*normal_dot_light_direction*att;
  	specular += this->specular*power_factor*att;
}