// Rotates a dodec about a vertex or edge to get a dual dodec.
private static Dodec GetDual(Dodec dodec, Vector3D rotationPoint)
{
//double rot = System.Math.PI / 2; // Edge-centered
double rot = 4 * (-Math.Atan((2 + Math.Sqrt(5) - 2 * Math.Sqrt(3 + Math.Sqrt(5))) / Math.Sqrt(3))); // Vertex-centered
Mobius m = new Mobius();
if (Infinity.IsInfinite(rotationPoint))
{
m.Elliptic(Geometry.Spherical, new Vector3D(), -rot);
}
else
{
m.Elliptic(Geometry.Spherical, rotationPoint, rot);
}
Dodec dual = new Dodec();
foreach (Vector3D v in dodec.Verts)
{
Vector3D rotated = m.ApplyInfiniteSafe(v);
dual.Verts.Add(rotated);
}
foreach (Vector3D v in dodec.Midpoints)
{
Vector3D rotated = m.ApplyInfiniteSafe(v);
dual.Midpoints.Add(rotated);
}
return(dual);
}
private static Mobius RotMobius(Vector3D vertex0)
{
// A third rotation about the vertex.
Mobius m = new Mobius();
m.Elliptic(Geometry.Hyperbolic, vertex0, 2 * Math.PI / 3);
return(m);
}
public Mobius MobiusForTwist(Geometry g, SingleTwist twist, double rotation, bool earthquake, bool earthquakeData = false)
{
Mobius mobius = new Mobius();
if (earthquake)
{
int seg = earthquakeData ?
(twist.SliceMaskEarthquake * 2 + 3) % 6 :
(twist.SliceMask * 2 + 3) % 6;
Vector3D p1 = this.Pants.Hexagon.Segments[seg].P2;
Vector3D p2 = Pants.Hexagon.Segments[seg].P1;
if (Pants.Isometry.Reflected)
{
R3.Core.Utils.SwapPoints(ref p1, ref p2);
}
System.Diagnostics.Debug.Assert(!Reverse);
mobius.Geodesic(Geometry.Hyperbolic, p1, p2, rotation);
}
else
{
mobius.Elliptic(g, Center, Reverse ? rotation * -1 : rotation);
}
return(mobius);
}
