public override Vector256 <float> Intersect(RayPacket256 rayPacket256)
{
var denom = VectorPacket256.DotProduct(Norms, rayPacket256.Dirs);
var dist = Divide(Add(VectorPacket256.DotProduct(Norms, rayPacket256.Starts), Offsets), Subtract(Vector256 <float> .Zero, denom));
var gtMask = Compare(denom, Vector256 <float> .Zero, FloatComparisonMode.OrderedGreaterThanNonSignaling);
return(BlendVariable(dist, Intersections.NullDistance, gtMask));
}
public override Vector256 <float> Intersect(RayPacket256 rayPacket256)
{
var eo = Centers - rayPacket256.Starts;
var v = VectorPacket256.DotProduct(eo, rayPacket256.Dirs);
var zero = SetZeroVector256 <float>();
var vLessZeroMask = Compare(v, zero, FloatComparisonMode.LessThanOrderedNonSignaling);
var discs = Subtract(Multiply(Radiuses, Radiuses), Subtract(VectorPacket256.DotProduct(eo, eo), Multiply(v, v)));
var discLessZeroMask = Compare(discs, zero, FloatComparisonMode.LessThanOrderedNonSignaling);
var dists = BlendVariable(Subtract(v, Sqrt(discs)), zero, Or(vLessZeroMask, discLessZeroMask));
var isZero = Compare(dists, zero, FloatComparisonMode.EqualOrderedNonSignaling);
return(BlendVariable(dists, Intersections.NullDistance, isZero));
}
private ColorPacket256 Shade(Intersections isect, RayPacket256 rays, Scene scene, int depth)
{
var ds = rays.Dirs;
var pos = isect.Distances * ds + rays.Starts;
var normals = scene.Normals(isect.ThingIndices, pos);
var reflectDirs = ds - (Multiply(VectorPacket256.DotProduct(normals, ds), Vector256.Create(2f)) * normals);
var colors = GetNaturalColor(isect.ThingIndices, pos, normals, reflectDirs, scene);
if (depth >= MaxDepth)
{
return(colors + new ColorPacket256(.5f, .5f, .5f));
}
return(colors + GetReflectionColor(isect.ThingIndices, pos + (Vector256.Create(0.001f) * reflectDirs), normals, reflectDirs, scene, depth));
}
private ColorPacket256 GetNaturalColor(Vector256 <int> things, VectorPacket256 pos, VectorPacket256 norms, VectorPacket256 rds, Scene scene)
{
var colors = ColorPacket256Helper.DefaultColor;
for (int i = 0; i < scene.Lights.Length; i++)
{
var lights = scene.Lights[i];
var zero = Vector256 <float> .Zero;
var colorPacket = lights.Colors;
var ldis = lights.Positions - pos;
var livec = ldis.Normalize();
var neatIsectDis = TestRay(new RayPacket256(pos, livec), scene);
// is in shadow?
var mask1 = Compare(neatIsectDis, ldis.Lengths, FloatComparisonMode.LessThanOrEqualOrderedNonSignaling);
var mask2 = Compare(neatIsectDis, zero, FloatComparisonMode.NotEqualOrderedNonSignaling);
var isInShadow = And(mask1, mask2);
Vector256 <float> illum = VectorPacket256.DotProduct(livec, norms);
Vector256 <float> illumGraterThanZero = Compare(illum, zero, FloatComparisonMode.GreaterThanOrderedNonSignaling);
var tmpColor1 = illum * colorPacket;
var defaultRGB = zero;
Vector256 <float> lcolorR = BlendVariable(defaultRGB, tmpColor1.Xs, illumGraterThanZero);
Vector256 <float> lcolorG = BlendVariable(defaultRGB, tmpColor1.Ys, illumGraterThanZero);
Vector256 <float> lcolorB = BlendVariable(defaultRGB, tmpColor1.Zs, illumGraterThanZero);
ColorPacket256 lcolor = new ColorPacket256(lcolorR, lcolorG, lcolorB);
Vector256 <float> specular = VectorPacket256.DotProduct(livec, rds.Normalize());
Vector256 <float> specularGraterThanZero = Compare(specular, zero, FloatComparisonMode.GreaterThanOrderedNonSignaling);
var difColor = new ColorPacket256(1, 1, 1);
var splColor = new ColorPacket256(1, 1, 1);
var roughness = Vector256.Create(1.0f);
for (int j = 0; j < scene.Things.Length; j++)
{
Vector256 <float> thingMask = CompareEqual(things, Vector256.Create(j)).AsSingle();
var rgh = Vector256.Create(scene.Things[j].Surface.Roughness);
var dif = scene.Things[j].Surface.Diffuse(pos);
var spl = scene.Things[j].Surface.Specular;
roughness = BlendVariable(roughness, rgh, thingMask);
difColor.Xs = BlendVariable(difColor.Xs, dif.Xs, thingMask);
difColor.Ys = BlendVariable(difColor.Ys, dif.Ys, thingMask);
difColor.Zs = BlendVariable(difColor.Zs, dif.Zs, thingMask);
splColor.Xs = BlendVariable(splColor.Xs, spl.Xs, thingMask);
splColor.Ys = BlendVariable(splColor.Ys, spl.Ys, thingMask);
splColor.Zs = BlendVariable(splColor.Zs, spl.Zs, thingMask);
}
var tmpColor2 = VectorMath.Pow(specular, roughness) * colorPacket;
Vector256 <float> scolorR = BlendVariable(defaultRGB, tmpColor2.Xs, specularGraterThanZero);
Vector256 <float> scolorG = BlendVariable(defaultRGB, tmpColor2.Ys, specularGraterThanZero);
Vector256 <float> scolorB = BlendVariable(defaultRGB, tmpColor2.Zs, specularGraterThanZero);
ColorPacket256 scolor = new ColorPacket256(scolorR, scolorG, scolorB);
var oldColor = colors;
colors = colors + ColorPacket256Helper.Times(difColor, lcolor) + ColorPacket256Helper.Times(splColor, scolor);
colors = new ColorPacket256(BlendVariable(colors.Xs, oldColor.Xs, isInShadow), BlendVariable(colors.Ys, oldColor.Ys, isInShadow), BlendVariable(colors.Zs, oldColor.Zs, isInShadow));
}
return(colors);
}