/// <summary>
///
/// </summary>
/// <param name="p0"></param>
/// <param name="p1"></param>
protected void Init(Coordinate p0, Coordinate p1)
{
_p0 = p0;
_p1 = p1;
_dx = p1.X - p0.X;
_dy = p1.Y - p0.Y;
_quadrant = QuadrantOp.Quadrant(_dx, _dy);
Assert.IsTrue(!(_dx == 0 && _dy == 0), "EdgeEnd with identical endpoints found");
}
/// <summary>
/// The coordinate pairs match if they define line segments lying in the same direction.
/// E.g. the segments are parallel and in the same quadrant
/// (as opposed to parallel and opposite!).
/// </summary>
/// <param name="p0"></param>
/// <param name="p1"></param>
/// <param name="ep0"></param>
/// <param name="ep1"></param>
private static bool MatchInSameDirection(Coordinate p0, Coordinate p1, Coordinate ep0, Coordinate ep1)
{
if (!p0.Equals(ep0))
{
return(false);
}
if (Orientation.Index(p0, p1, ep1) == OrientationIndex.Collinear &&
QuadrantOp.Quadrant(p0, p1) == QuadrantOp.Quadrant(ep0, ep1))
{
return(true);
}
return(false);
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public DirectedEdge GetRightmostEdge()
{
IList <EdgeEnd> edges = Edges;
int size = edges.Count;
if (size < 1)
{
return(null);
}
DirectedEdge de0 = (DirectedEdge)edges[0];
if (size == 1)
{
return(de0);
}
DirectedEdge deLast = (DirectedEdge)edges[size - 1];
int quad0 = de0.Quadrant;
int quad1 = deLast.Quadrant;
if (QuadrantOp.IsNorthern(quad0) && QuadrantOp.IsNorthern(quad1))
{
return(de0);
}
else if (!QuadrantOp.IsNorthern(quad0) && !QuadrantOp.IsNorthern(quad1))
{
return(deLast);
}
else
{
// edges are in different hemispheres - make sure we return one that is non-horizontal
if (de0.Dy != 0)
{
return(de0);
}
else if (deLast.Dy != 0)
{
return(deLast);
}
}
Assert.ShouldNeverReachHere("found two horizontal edges incident on node");
return(null);
}