private static Tuple<LightStrength, double> CalculateLighting(IGeometry[] spheres, Vector3D directionToEye, Vector3D surfaceNormal, Material sphere, Vector3D intersectionPoint, Light light)
{
var directionToLight = light.CenterPoint - intersectionPoint;
directionToLight.Normalize();
var lightT = (light.CenterPoint.X - intersectionPoint.X)/directionToLight.X;
var blocked = spheres.Any(s => ObscuresLight(s, intersectionPoint, directionToLight, lightT));
if (blocked)
{
return Tuple.Create(LightStrength.Zero,0.0);
}
var ldotn = Math.Max(0.0,Vector3D.DotProduct(surfaceNormal, directionToLight));
var diffuse = light.Brightness*ldotn;
var H = directionToLight + directionToEye;
H.Normalize();
var ndoth = Math.Max(0.0,Vector3D.DotProduct(surfaceNormal, H));
var specular = Math.Pow(ndoth, sphere.Shinyness);
return Tuple.Create(diffuse, specular);
}
