/// <summary>
/// Find the next edge clockwise with the same destination. [dprev(abc) -> cb*]
/// </summary>
/// <remarks>dprev() spins clockwise around a vertex; that is, it finds the
/// next edge with the same destination in the clockwise direction. This edge
/// is part of a different triangle.
/// </remarks>
public void Dprev(ref Otri o2)
{
//Lnext(ref o2);
o2.triangle = triangle;
o2.orient = plus1Mod3[orient];
//o2.SymSelf();
int tmp = o2.orient;
o2.orient = o2.triangle.neighbors[tmp].orient;
o2.triangle = o2.triangle.neighbors[tmp].triangle;
}
/// <summary>
/// Find the previous edge (clockwise) of the adjacent triangle. [rprev(abc) -> b**]
/// </summary>
/// <remarks>rprev() moves one edge clockwise about the adjacent triangle.
/// (It's best understood by reading Guibas and Stolfi. It involves
/// changing triangles twice.)
/// </remarks>
public void Rprev(ref Otri o2)
{
//Sym(ref o2);
o2.triangle = triangle.neighbors[orient].triangle;
o2.orient = triangle.neighbors[orient].orient;
//o2.LprevSelf();
o2.orient = minus1Mod3[o2.orient];
//o2.SymSelf();
int tmp = o2.orient;
o2.orient = o2.triangle.neighbors[tmp].orient;
o2.triangle = o2.triangle.neighbors[tmp].triangle;
}
/// <summary>
/// Finds a triangle abutting a subsegment.
/// </summary>
public void TriPivot(ref Otri ot)
{
ot = seg.triangles[orient];
//decode(ptr, otri)
}
/// <summary>
/// Find the previous edge (clockwise) of a triangle. [lprev(abc) -> cab]
/// </summary>
public void Lprev(ref Otri o2)
{
o2.triangle = triangle;
o2.orient = minus1Mod3[orient];
}
// lnext() finds the next edge (counterclockwise) of a triangle.
/// <summary>
/// Find the next edge (counterclockwise) of a triangle. [lnext(abc) -> bca]
/// </summary>
public void Lnext(ref Otri o2)
{
o2.triangle = triangle;
o2.orient = plus1Mod3[orient];
}
/// <summary>
/// Test for equality of oriented triangles.
/// </summary>
public bool Equal(Otri o2)
{
return((triangle == o2.triangle) && (orient == o2.orient));
}
/// <summary>
/// Copy an oriented triangle.
/// </summary>
public void Copy(ref Otri o2)
{
o2.triangle = triangle;
o2.orient = orient;
}