protected (bool, float, float, float) TestLocalIntersection(Ray localRay)
{
Tuple dirCrossE2 = localRay.Direction.Cross(E2);
float det = E1.Dot(dirCrossE2);
if (Abs(det) < Constants.floatEps)
{
return(false, 0, 0, 0);
}
float invDet = 1.0f / det;
Tuple p1ToOrigin = localRay.Origin - P1;
float u = invDet * p1ToOrigin.Dot(dirCrossE2);
if (u < 0 || u > 1)
{
return(false, 0, 0, 0);
}
Tuple originCrossE1 = p1ToOrigin.Cross(E1);
float v = invDet * localRay.Direction.Dot(originCrossE1);
if (v < 0 || (u + v) > 1)
{
return(false, 0, 0, 0);
}
float t = invDet * E2.Dot(originCrossE1);
return(true, t, u, v);
}
public override Tuple Lighting(Material m, Shape shape, Light l, Tuple position, Tuple toEye, Tuple normal, bool inShadow)
{
Tuple color = (m.Pattern == null)? m.Color : m.Pattern.ColorAtShape(shape, position);
Tuple effectiveColor = color * l.Intensity;
Tuple toLight = (l.Position - position).Normalize();
Tuple ambient = effectiveColor * m.Ambient;
float ndotl = normal.Dot(toLight);
Tuple diffuse = Tuple.Color(0, 0, 0);
Tuple specular = Tuple.Color(0, 0, 0);
if ((inShadow == false) && (ndotl >= 0))
{
diffuse = effectiveColor * m.Diffuse * ndotl;
Tuple reflect = (-toLight).Reflect(normal);
float rdote = reflect.Dot(toEye);
if (rdote > 0)
{
specular = l.Intensity * m.Specular * Pow(rdote, m.Shininess);
}
}
return(ambient + diffuse + specular);
}
protected override List <Intersection> LocalIntersect(Ray localRay)
{
Tuple sphereToRay = localRay.Origin - Tuple.Point(0, 0, 0);
float a = localRay.Direction.Dot(localRay.Direction);
float b = localRay.Direction.Dot(sphereToRay);
float c = sphereToRay.Dot(sphereToRay) - 1;
float discriminant = b * b - a * c;
if (discriminant >= 0)
{
float sqrtDisc = System.MathF.Sqrt(discriminant);
return(Intersection.Aggregate(
new Intersection((-b - sqrtDisc) / a, this),
new Intersection((-b + sqrtDisc) / a, this)));
}
return(Intersection.Aggregate());
}
