///<summary>
/// Turns an edge counterclockwise inside its enclosing quadrilateral.
///</summary>
///<param name="e">the quadedge to turn</param>
public static void Swap(QuadEdge e)
{
QuadEdge a = e.OriginPrev;
QuadEdge b = e.Sym().OriginPrev;
Splice(e, a);
Splice(e.Sym(), b);
Splice(e, a.LeftNext);
Splice(e.Sym(), b.LeftNext);
e.Origin = a.Destination;
e.Destination = b.Destination;
}
///<summary>
/// Creates a new QuadEdge connecting the destination of a to the origin of
/// b, in such a way that all three have the same left face after the
/// connection is complete. Additionally, the data pointers of the new edge
/// are set.
///</summary>
///<param name="a"></param>
///<param name="b"></param>
///<returns>the connected edge</returns>
public static QuadEdge Connect(QuadEdge a, QuadEdge b)
{
QuadEdge e = MakeEdge(a.Destination, b.Origin);
Splice(e, a.LeftNext);
Splice(e.Sym(), b);
return(e);
}
///<summary>
/// Tests if this quadedge and another have the same line segment geometry,
///</summary>
///<param name="qe">a quadege</param>
///<returns>true if the quadedges are based on the same line segment regardless of orientation regardless of orientation.</returns>
public Boolean EqualsNonOriented(QuadEdge qe)
{
if (EqualsOriented(qe))
{
return(true);
}
if (EqualsOriented(qe.Sym()))
{
return(true);
}
return(false);
}
///<summary>
/// Gets the dual of this edge, directed from its left to its right.
///</summary>
///<returns>the inverse rotated edge.</returns>
public QuadEdge InverseRot()
{
return(_rot.Sym());
}