+ while(LightUnit *unit = LightUnit::find_unit(this))
+ unbind_from(unit->get_index());
+}
+
+void Light::update_parameter(int mask, int index) const
+{
+ if(index<0)
+ {
+ LightUnit *unit = LightUnit::find_unit(this);
+ if(!unit)
+ return;
+
+ index = unit->get_index();
+ }
+
+ GLenum l = GL_LIGHT0+index;
+ if(mask&DIFFUSE)
+ glLightfv(l, GL_DIFFUSE, &diffuse.r);
+ if(mask&SPECULAR)
+ glLightfv(l, GL_SPECULAR, &specular.r);
+ if(mask&POSITION)
+ glLightfv(l, GL_POSITION, &position.x);
+ if(mask&SPOT_DIR)
+ glLightfv(l, GL_SPOT_DIRECTION, &spot_dir.x);
+ if(mask&SPOT_EXP)
+ glLightf(l, GL_SPOT_EXPONENT, spot_exp);
+ if(mask&SPOT_CUTOFF)
+ glLightf(l, GL_SPOT_CUTOFF, spot_cutoff.degrees());
+ if(mask&ATTENUATION)
+ {
+ glLightf(l, GL_CONSTANT_ATTENUATION, attenuation[0]);
+ glLightf(l, GL_LINEAR_ATTENUATION, attenuation[1]);
+ glLightf(l, GL_QUADRATIC_ATTENUATION, attenuation[2]);
+ }
+}
+
+void Light::update_matrix()
+{
+ Vector3 up_dir;
+ if(20*abs(direction.z)>abs(direction.x)+abs(direction.y))
+ up_dir.y = 1;
+ else
+ up_dir.z = 1;
+ Vector3 right_dir = normalize(cross(direction, up_dir));
+
+ Vector4 columns[4];
+ columns[0] = compose(right_dir, 0.0f);
+ columns[1] = compose(cross(right_dir, direction), 0.0f);
+ columns[2] = compose(-direction, 0.0f);
+ columns[3] = position;
+ matrix = Matrix::from_columns(columns);