// public virtual uint MethodReturn(uint arg)
// {
// object[] arr = { CurrentMethod, arg };
// WriteLine(_mt, TRACE_RETURN_GEN_FMT, arr);
// return arg;
// }
//
// public virtual ulong MethodReturn(ulong arg)
// {
// object[] arr = { CurrentMethod, arg };
// WriteLine(_mt, TRACE_RETURN_GEN_FMT, arr);
// return arg;
// }
public virtual Traceable MethodReturn(Traceable arg)
{
object[] arr = { CurrentMethod, arg == null ? "null" : arg.TraceString };
WriteLine(_mt, TRACE_RETURN_GEN_FMT, arr);
return(arg);
}
/// <summary>
/// Trace a ray and return the RGB color vector.
/// </summary>
/// <param name="ray">The current ray being traced.</param>
/// <param name="objects">The collection of tracable objects.</param>
/// <param name="lights">The collection of lights</param>
/// <param name="eye">The eye vector</param>
/// <returns>The RGB color vector3 if the ray hits an object, otherwise null.</returns>
public static Color Trace(this Ray ray, IEnumerable <Traceable> objects, IEnumerable <Light> lights, Vector3 eye, Color ambientLight)
{
if (objects == null)
{
throw new ArgumentNullException(nameof(objects));
}
if (lights == null)
{
throw new ArgumentNullException(nameof(lights));
}
if (eye == null)
{
throw new ArgumentNullException(nameof(eye));
}
float hit;
float[] hits;
float nearestHit = (float)Util.NearlyInfinite;
Traceable nearestObject = null;
foreach (var t in objects)
{
hits = t.Intersections(ray);
if (hits.Any())
{
hit = hits.First();
if (hit < nearestHit)
{
nearestHit = hit;
nearestObject = t;
}
}
}
if (nearestObject == null)
{
return(Color.Black);
}
else
{
var normal = nearestObject.GetNormalAt(ray.PointAt(nearestHit));
var baseColor = nearestObject.GetBaseColorAt(ray.PointAt(nearestHit))
.ToVector();
var color = Vector3.Multiply(baseColor, ambientLight.ToVector());
Vector3 lightVector,
lightColorVector,
viewingVector,
diffuseContribution,
specularContribution,
halfVector;
float lDotN, hDotN;
foreach (var l in lights)
{
lightVector = l.GetLightVector(ray.PointAt((float)nearestHit));
lightColorVector = l.Color.ToVector();
lDotN = Vector3.Dot(lightVector, normal);
if (lDotN > 0)
{
// Diffuse light contribution
diffuseContribution = Vector3.Multiply(Vector3.Multiply(baseColor, lightColorVector), lDotN);
color = color + diffuseContribution;
// Specular light contribution
viewingVector = Vector3.Normalize(eye - nearestObject.Model.Origin.Image(ray.PointAt(nearestHit)));
halfVector = Vector3.Normalize(viewingVector + lightVector);
hDotN = Vector3.Dot(halfVector, normal);
if (hDotN > 0)
{
specularContribution = Vector3.Multiply(Vector3.Multiply(nearestObject.SpecularColor.ToVector(), lightColorVector),
(float)Math.Pow(hDotN, nearestObject.SpecularExponent));
color = color + specularContribution;
}
}
}
return(color.Clamp().ToColor());
}
}
// public override uint MethodReturn(uint arg)
// {
// base.MethodReturn(arg);
// PopCurrentMethod();
// return arg;
// }
//
// public override ulong MethodReturn(ulong arg)
// {
// base.MethodReturn(arg);
// PopCurrentMethod();
// return arg;
// }
public override Traceable MethodReturn(Traceable arg)
{
base.MethodReturn(arg);
PopCurrentMethod();
return(arg);
}
//////////////////////////////////////////////////////////////
/// <summary>
/// This method allows adding traceable contents via
/// TraceString instead of ToString.
/// </summary>
/// <param name="traceable">the traceable instance</param>
/// <returns>the StringBuilder reference</returns>
//////////////////////////////////////////////////////////////
public StringBuilder Append(Traceable traceable)
{
return(_buf.Append(traceable.TraceString));
}
