/// <summary>
/// Intersection test with an <see cref="AxisAlignedBox2"/>.
/// </summary>
/// <remarks>
/// May return false positives but will never miss an intersection.
/// </remarks>
/// <param name="box">Box to test.</param>
/// <returns>True if interesecting, false otherwise.</returns>
public bool Intersects(AxisAlignedBox3 box)
{
if (box.IsNull)
{
return(false);
}
if (box.IsInfinite)
{
return(true);
}
// Get centre of the box
Vector3 center = box.Center;
// Get the half-size of the box
Vector3 halfSize = box.HalfSize;
// If all points are on outside of any plane, we fail
Vector3[] points = box.Corners;
for (int i = 0; i < planes.Count; i++)
{
Plane plane = (Plane)planes[i];
PlaneSide side = plane.GetSide(center, halfSize);
if (side == outside)
{
// Found a splitting plane therefore return not intersecting
return(false);
}
}
// couldn't find a splitting plane, assume intersecting
return(true);
}
/// <summary>
/// Returns the side where the aligneBox is. the flag Both indicates an intersecting box.
/// one corner ON the plane is sufficient to consider the box and the plane intersecting.
/// </summary>
/// <param name="box"></param>
/// <returns></returns>
public PlaneSide GetSide(AxisAlignedBox3 box)
{
if (box.IsNull)
{
return(PlaneSide.None);
}
if (box.IsInfinite)
{
return(PlaneSide.Both);
}
return(this.GetSide(box.Center, box.HalfSize));
}
/// <summary>
/// Returns whether or not this box intersects another.
/// </summary>
/// <param name="box2"></param>
/// <returns>True if the 2 boxes intersect, false otherwise.</returns>
public bool Intersects(AxisAlignedBox3 box2)
{
// Early-fail for nulls
if (this.IsNull || box2.IsNull)
{
return(false);
}
if (this.IsInfinite || box2.IsInfinite)
{
return(true);
}
// Use up to 6 separating planes
if (this.maxVector.X <= box2.minVector.X)
{
return(false);
}
if (this.maxVector.Y <= box2.minVector.Y)
{
return(false);
}
if (this.maxVector.Z <= box2.minVector.Z)
{
return(false);
}
if (this.minVector.X >= box2.maxVector.X)
{
return(false);
}
if (this.minVector.Y >= box2.maxVector.Y)
{
return(false);
}
if (this.minVector.Z >= box2.maxVector.Z)
{
return(false);
}
// otherwise, must be intersecting
return(true);
}
/// <summary>
/// Allows for merging two boxes together (combining).
/// </summary>
/// <param name="box">Source box.</param>
public void Merge(AxisAlignedBox3 box)
{
if (box.IsNull)
{
// nothing to merge with in this case, just return
return;
}
else if (box.IsInfinite)
{
this.IsInfinite = true;
}
else if (this.IsNull)
{
SetExtents(box.Minimum, box.Maximum);
}
else if (!this.IsInfinite)
{
minVector.Floor(box.Minimum);
maxVector.Ceil(box.Maximum);
UpdateCorners();
}
}
public AxisAlignedBox3(AxisAlignedBox3 box)
{
SetExtents(box.Minimum, box.Maximum);
isNull = box.IsNull;
isInfinite = box.IsInfinite;
}
/// <summary>
/// Calculate the area of intersection of this box and another
/// </summary>
public AxisAlignedBox3 Intersection(AxisAlignedBox3 b2)
{
if (!Intersects(b2))
{
return(new AxisAlignedBox3());
}
Vector3 intMin = Vector3.Zero;
Vector3 intMax = Vector3.Zero;
Vector3 b2max = b2.maxVector;
Vector3 b2min = b2.minVector;
if (b2max.X > maxVector.X && maxVector.X > b2min.X)
{
intMax.X = maxVector.X;
}
else
{
intMax.X = b2max.X;
}
if (b2max.Y > maxVector.Y && maxVector.Y > b2min.Y)
{
intMax.Y = maxVector.Y;
}
else
{
intMax.Y = b2max.Y;
}
if (b2max.Z > maxVector.Z && maxVector.Z > b2min.Z)
{
intMax.Z = maxVector.Z;
}
else
{
intMax.Z = b2max.Z;
}
if (b2min.X < minVector.X && minVector.X < b2max.X)
{
intMin.X = minVector.X;
}
else
{
intMin.X = b2min.X;
}
if (b2min.Y < minVector.Y && minVector.Y < b2max.Y)
{
intMin.Y = minVector.Y;
}
else
{
intMin.Y = b2min.Y;
}
if (b2min.Z < minVector.Z && minVector.Z < b2max.Z)
{
intMin.Z = minVector.Z;
}
else
{
intMin.Z = b2min.Z;
}
return(new AxisAlignedBox3(intMin, intMax));
}