private double? testRay(Ray ray, Scene scene)
{
var isect = this.intersections(ray, scene);
if (isect != null)
{
return isect.dist;
}
else
{
return null;
}
}
private Color traceRay(Ray ray, Scene scene, double depth)
{
var isect = this.intersections(ray, scene);
if (isect == null)
{
return Color.background;
}
else
{
return this.shade(isect, scene, depth);
}
}
private Intersection intersections(Ray ray, Scene scene)
{
var closest = double.PositiveInfinity;
Intersection closestInter = null;
foreach (var i in scene.things)
{
var inter = i.intersect(ray);
if (inter != null && inter.dist < closest)
{
closestInter = inter;
closest = inter.dist;
}
}
return closestInter;
}
public override Intersection intersect(Ray ray)
{
var denom = Vector.dot(norm, ray.dir);
if (denom > 0)
{
return null;
}
else
{
var dist = (Vector.dot(norm, ray.start) + offset) / (-denom);
return new Intersection(this, ray, dist);
}
}
public override Intersection intersect(Ray ray)
{
var eo = Vector.minus(this.center, ray.start);
var v = Vector.dot(eo, ray.dir);
var dist = 0.0;
if (v >= 0)
{
var disc = this.radius2 - (Vector.dot(eo, eo) - v * v);
if (disc >= 0)
{
dist = v - Math.Sqrt(disc);
}
}
if (dist == 0)
{
return null;
}
else
{
return new Intersection(this, ray, dist);
}
}
abstract public Intersection intersect(Ray ray);
public Intersection(Thing thing, Ray ray, double dist)
{
this.thing = thing;
this.ray = ray;
this.dist = dist;
}