public static Trafo3d FromNormalFrame(V3d origin, V3d normal)
{
M44d forward, backward;
M44d.NormalFrame(origin, normal, out forward, out backward);
return(new Trafo3d(forward, backward));
}
/// <summary>
/// 2D plane space to 3D world space.
/// Plane space is defined by a normal-frame from Point and Normal of the plane.
/// </summary>
public static M44d GetPlaneToWorld(this Plane3d self)
{
M44d local2global, _;
M44d.NormalFrame(self.Point, self.Normal, out local2global, out _);
return(local2global);
}
/// <summary>
/// 3D world space to 2D plane space.
/// Plane space is defined by a normal-frame from Point and Normal of the plane.
/// </summary>
public static M44d GetWorldToPlane(this Plane3d self)
{
M44d _, global2local;
M44d.NormalFrame(self.Point, self.Normal, out _, out global2local);
return(global2local);
}
public static List <int[]> ComputeNonConcaveSubPolygons(
this Polygon3d polygon, double absoluteEpsilon)
{
V3d normal = polygon.ComputeDoubleAreaNormal();
double len2 = normal.LengthSquared;
if (len2 < absoluteEpsilon * absoluteEpsilon)
{
return(new int[polygon.PointCount].SetByIndex(i => i).IntoList());
}
M44d.NormalFrame(V3d.Zero, normal * (1.0 / Fun.Sqrt(len2)), out M44d local2global, out M44d global2local);
var polygon2d = polygon.ToPolygon2d(p => global2local.TransformPos(p).XY);
return(polygon2d.ComputeNonConcaveSubPolygons(absoluteEpsilon));
}
public static List <int[]> ComputeNonConcaveSubPolygons(
this V3d[] vertexArray, int polyCount,
V3d[] normalArray, int[] firstIndices, int[] vertexIndices,
List <int> faceBackMap,
double absoluteEpsilon)
{
var polyList = new List <int[]>();
var eps2 = absoluteEpsilon * absoluteEpsilon;
for (int fvi = 0, fi = 0; fi < polyCount; fi++)
{
int fve = firstIndices[fi + 1], fvc = fve - fvi;
var n = normalArray[fi];
var l2 = n.LengthSquared;
if (l2 < eps2)
{
polyList.Add(new int[fvc].SetByIndex(i => vertexIndices[fvi + i]));
if (faceBackMap != null)
{
faceBackMap.Add(fi);
}
fvi = fve;
continue;
}
M44d local2global, global2local;
M44d.NormalFrame(V3d.Zero, n, out local2global, out global2local);
var polygon = new Polygon2d(fvc,
i => global2local.TransformPos(vertexArray[vertexIndices[fvi + i]]).XY);
var subPolyList = polygon.ComputeNonConcaveSubPolygons(absoluteEpsilon);
foreach (var poly in subPolyList)
{
polyList.Add(poly.Map(i => fvi + i));
}
if (faceBackMap != null)
{
for (int i = 0; i < subPolyList.Count; i++)
{
faceBackMap.Add(fi);
}
}
fvi = fve;
}
return(polyList);
}