public AntiIntersection AntiIntersect(Ray ray, SphereBase parentSphere)
{
Vector3 l = GetPosition() - ray.GetStart(); //Vector to sphere center (and direction)
float tc = Vector3.Dot(l, ray.GetDirection()); //Length to ray hit-center
float els = Vector3.Dot(l, l);
float radiusSquared = _radius * _radius;
if (tc < 0 && els > radiusSquared)
{
return(AntiIntersection.CreateNullAntiIntersection());
}
float dSquared = els - tc * tc; //Squared perpendicular distance from spherecenter to ray (vinkelrätt)
if (dSquared > radiusSquared)
{
return(AntiIntersection.CreateNullAntiIntersection());
}
float t1c = (float)Math.Sqrt(radiusSquared - dSquared);
float tNear, tFar;
tNear = tc - t1c;
tFar = tc + t1c;
Vector3 pNear = ray.GetStart() + Vector3.Multiply(ray.GetDirection(), tNear);
Vector3 pFar = ray.GetStart() + Vector3.Multiply(ray.GetDirection(), tFar);
var normNearTexture = Vector3.Normalize(Vector3.Divide(GetPosition() - pNear, _radius));
var normFarTexture = Vector3.Normalize(Vector3.Divide(GetPosition() - pFar, _radius));
return(new AntiIntersection(pNear, pFar, normNearTexture, normFarTexture, tNear, tFar, this));
}
protected void insertAntiIntersectionSortedToArray(AntiIntersection[] array, int maxPosition, AntiIntersection item)
{
if (maxPosition == 0)
{
array[0] = item;
return;
}
//Sort at insert
for (int i = maxPosition - 1; i >= 0; i--)
{
if (item.GetTNear() > array[i].GetTNear() | item.IsNull())
{
array[i + 1] = item;
break;
}
else
{
array[i + 1] = array[i];
if (i == 0)
{
array[0] = item;
}
}
}
}
private AntiIntersection getFarthestAntiIntersection(float tMin, float tMax, AntiIntersection[] antiSphereIntersectionList)
{
AntiIntersection farthestAntiIntersection = AntiIntersection.CreateNullAntiIntersection();
tMin = (tMin < 0) ? 0 : tMin;
float tCurrent = tMin;
//compare the hits in the antilist
foreach (AntiIntersection antiIntersection in antiSphereIntersectionList)
{
//Break here, because the sorting places all the missed intersections in the end
if (!antiIntersection.IsHit())
{
break;
}
if (antiIntersection.isDistanceInside(tCurrent))
{
//Move away the nearest hit to the other side of the AntiSphere
tCurrent = antiIntersection.GetTFar();
farthestAntiIntersection = antiIntersection;
}
if (tCurrent >= tMax)
{
//It went through
farthestAntiIntersection = AntiIntersection.CreateInfiniteAntiIntersection();
break;
}
}
return(farthestAntiIntersection);
}
protected void calculateAntiSphereIntersections(Ray ray, out AntiIntersection[] antiSphereIntersectionList, out bool antiSphereIntersectionListIsHit)
{
//Local array will help about thread issues
antiSphereIntersectionList = new AntiIntersection[_antiSphereList.Count];
antiSphereIntersectionListIsHit = false;
for (int i = 0; i < _antiSphereList.Count; i++)
{
var intersection = _antiSphereList[i].AntiIntersect(ray, this);
antiSphereIntersectionListIsHit = antiSphereIntersectionListIsHit | intersection.IsHit();
insertAntiIntersectionSortedToArray(antiSphereIntersectionList, i, intersection);
}
}
protected Intersection getClosestIntersectionFromAntiSpheres(Intersection sphereIntersection, Ray ray)
{
bool insideSphere = sphereIntersection.GetTFirstHit() == sphereIntersection.GetTFar();
AntiIntersection[] antiSphereIntersectionList;
bool antiSphereIntersectionListIsHit;
calculateAntiSphereIntersections(ray, out antiSphereIntersectionList, out antiSphereIntersectionListIsHit);
if (antiSphereIntersectionListIsHit)
{
AntiIntersection farthestAntiIntersection = getFarthestAntiIntersection(sphereIntersection.GetTNear(), sphereIntersection.GetTFar(), antiSphereIntersectionList);
if (farthestAntiIntersection.IsHit())
{
var intersection = this.Intersect(farthestAntiIntersection.GetPositionFar(), farthestAntiIntersection.GetNormalFarTexture());
sphereIntersection = farthestAntiIntersection.CreateIntersection(intersection.GetNormalFirstHitTexture());
}
else if (farthestAntiIntersection.IsInfinite())
{
sphereIntersection = new Intersection(true);
}
}
return(sphereIntersection);
}
public void SetAntiIntersection(AntiIntersection antiIntersection)
{
_antiIntersection = antiIntersection;
}
public AntiSphereAntiIntersection(AntiSphere antiSphere)
{
_antiSphere = antiSphere;
_antiIntersection = AntiIntersection.CreateNullAntiIntersection();
}
