public bool Intersects(BoundingBox box)
{
if (box.Min.X >= Max.X || box.Max.X <= Min.X)
{
return false;
}
if (box.Min.Y >= Max.Y || box.Max.Y <= Min.Y)
{
return false;
}
if (box.Min.Z >= Max.Z || box.Max.Z <= Min.Z)
{
return false;
}
return true;
}
public double? Intersects(BoundingBox boundingBox)
{
double tNear = int.MinValue;
double tFar = int.MaxValue;
#region - X -
if (Direction.X == 0 && Origin.X < boundingBox.Min.X && Origin.X > boundingBox.Max.X)
{
// Ray is paralell and outside planes
return null;
}
else
{
double t1 = (boundingBox.Min.X - Origin.X) / Direction.X;
double t2 = (boundingBox.Max.X - Origin.X) / Direction.X;
if (t1 > t2)
{
MathHelper.Swap(ref t1, ref t2);
}
if (t1 > tNear)
{
tNear = t1;
}
if (t2 < tFar)
{
tFar = t2;
}
if (tNear > tFar || tFar < 0)
{
return null;
}
}
#endregion
#region - Y -
if (Direction.Y == 0 && Origin.Y < boundingBox.Min.Y && Origin.Y > boundingBox.Max.Y)
{
// Ray is paralell and outside planes
return null;
}
else
{
double t1 = (boundingBox.Min.Y - Origin.Y) / Direction.Y;
double t2 = (boundingBox.Max.Y - Origin.Y) / Direction.Y;
if (t1 > t2)
{
MathHelper.Swap(ref t1, ref t2);
}
if (t1 > tNear)
{
tNear = t1;
}
if (t2 < tFar)
{
tFar = t2;
}
if (tNear > tFar || tFar < 0)
{
return null;
}
}
#endregion
#region - Z -
if (Direction.Z == 0 && Origin.Z < boundingBox.Min.Z && Origin.Z > boundingBox.Max.Z)
{
// Ray is paralell and outside planes
return null;
}
else
{
double t1 = (boundingBox.Min.Z - Origin.Z) / Direction.Z;
double t2 = (boundingBox.Max.Z - Origin.Z) / Direction.Z;
if (t1 > t2)
{
MathHelper.Swap(ref t1, ref t2);
}
if (t1 > tNear)
{
tNear = t1;
}
if (t2 < tFar)
{
tFar = t2;
}
if (tNear > tFar || tFar < 0)
{
return null;
}
}
#endregion
return tNear;
}
public double IntersectionVolume(BoundingBox box)
{
double intersectionVolume = 1;
if (!Intersects(box))
{
return 0;
}
List<double> points = new List<double>();
points.Add(Min.X);
points.Add(box.Min.X);
points.Add(Max.X);
points.Add(box.Max.X);
points.Sort();
intersectionVolume *= points[2] - points[1];
points.Clear();
points.Add(Min.Y);
points.Add(box.Min.Y);
points.Add(Max.Y);
points.Add(box.Max.Y);
points.Sort();
intersectionVolume *= points[2] - points[1];
points.Clear();
points.Add(Min.Z);
points.Add(box.Min.Z);
points.Add(Max.Z);
points.Add(box.Max.Z);
points.Sort();
intersectionVolume *= points[2] - points[1];
return intersectionVolume;
}