private Color getNaturalColor(Thing thing, Vector pos, Vector norm, Vector rd, Scene scene)
{
this.thing = thing;
this.pos = pos;
this.norm = norm;
this.rd = rd;
this.scene = scene;
return Reduce(scene.lights, Color.defaultColor);
}
public void render(Scene scene, CanvasRenderingContext2D ctx, double screenWidth, double screenHeight)
{
this.screenWidth = screenWidth;
this.screenHeight = screenHeight;
for (var y = 0; y < screenHeight; y++)
{
for (var x = 0; x < screenWidth; x++)
{
var color = this.traceRay( new Ray(scene.camera.pos, getPoint(x, y, scene.camera)), scene, 0);
var c = Color.toDrawingColor(color);
ctx.fillStyle = "rgb(" + c.r + ", " + c.g + ", " + c.b + ")";
ctx.fillRect(x, y, x + 1, y + 1);
}
}
}
private Color getReflectionColor(Thing thing, Vector pos, Vector normal, Vector rd, Scene scene, double depth)
{
return Color.scale(thing.surface.reflect(pos), this.traceRay(new Ray (pos, rd), scene, depth + 1));
}
private Color shade(Intersection isect, Scene scene, double depth)
{
var d = isect.ray.dir;
var pos = Vector.plus(Vector.times(isect.dist, d), isect.ray.start);
var normal = isect.thing.normal(pos);
var reflectDir = Vector.minus(d, Vector.times(2, Vector.times(Vector.dot(normal, d), normal)));
var naturalColor = Color.plus(Color.background, this.getNaturalColor(isect.thing, pos, normal, reflectDir, scene));
var reflectedColor = (depth >= this.maxDepth) ? Color.grey : this.getReflectionColor(isect.thing, pos, normal, reflectDir, scene, depth);
return Color.plus(naturalColor, reflectedColor);
}
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 double? testRay(Ray ray, Scene scene)
{
var isect = this.intersections(ray, scene);
if (isect != null)
{
return isect.dist;
}
else
{
return null;
}
}
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;
}