/// <summary>
/// Returns true if the supplied point is inside a hull with
/// planes whose normal vectors point to the inside of the hull.
/// The optional offset parameter is measured in normal direction,
/// i.e. a positive offset makes the hull smaller.
/// </summary>
public static bool IsInsideInwardHull(this V2d point, Hull2d hull, double offset = 0.0)
{
for (int i = 0; i < hull.PlaneCount; i++)
{
if (hull.PlaneArray[i].Height(point) < offset)
{
return(false);
}
}
return(true);
}
public void TransformInto(Trafo2d trafo, ref Hull2d hull)
{
int count = PlaneCount;
var invTr = trafo.Backward.Transposed;
for (int i = 0; i < count; i++)
{
hull.PlaneArray[i]
= new Plane2d(
invTr.TransformDir(PlaneArray[i].Normal).Normalized,
trafo.Forward.TransformPos(PlaneArray[i].Point));
}
}
public Hull2d Transformed(Trafo2d trafo)
{
int count = PlaneCount;
var hull = new Hull2d(new Plane2d[count]);
var invTr = trafo.Backward.Transposed;
for (int i = 0; i < count; i++)
{
hull.PlaneArray[i]
= new Plane2d(
invTr.TransformDir(PlaneArray[i].Normal).Normalized,
trafo.Forward.TransformPos(PlaneArray[i].Point));
}
return(hull);
}
/// <summary>
/// Returns unordered set of corners of this hull.
/// </summary>
public static HashSet <V2d> ComputeCorners(this Hull2d hull)
{
var corners = new HashSet <V2d>();
int count = hull.PlaneArray.Length;
for (var i0 = 0; i0 < count; i0++)
{
for (var i1 = i0 + 1; i1 < count; i1++)
{
if (hull.PlaneArray[i0].Intersects(hull.PlaneArray[i1], out V2d temp))
{
if (temp.IsNaN || temp.AnyInfinity)
{
continue;
}
var inside = true;
for (var j = 0; j < count; j++)
{
if (j == i0 || j == i1)
{
continue;
}
var h = hull.PlaneArray[j].Height(temp);
if (h > 0)
{
inside = false; break;
}
}
if (inside)
{
corners.Add(temp);
}
}
}
}
return(corners);
}
public Hull2d(Hull2d hull)
{
PlaneArray = hull.PlaneArray.Copy();
}