/// <summary>
/// Create a new "split edge" with the section of points between
/// (and including) the two intersections.
/// The label for the new edge is the same as the label for the parent edge.
/// </summary>
/// <param name="ei0"></param>
/// <param name="ei1"></param>
public Edge CreateSplitEdge(EdgeIntersection ei0, EdgeIntersection ei1)
{
int npts = ei1.SegmentIndex - ei0.SegmentIndex + 2;
var lastSegStartPt = edge.Points[ei1.SegmentIndex];
// if the last intersection point is not equal to the its segment start pt,
// add it to the points list as well.
// (This check is needed because the distance metric is not totally reliable!)
// The check for point equality is 2D only - Z values are ignored
bool useIntPt1 = ei1.Distance > 0.0 || !ei1.Coordinate.Equals2D(lastSegStartPt);
if (!useIntPt1)
{
npts--;
}
var pts = new Coordinate[npts];
int ipt = 0;
pts[ipt++] = ei0.Coordinate.Copy();
for (int i = ei0.SegmentIndex + 1; i <= ei1.SegmentIndex; i++)
{
pts[ipt++] = edge.Points[i];
}
if (useIntPt1)
{
pts[ipt] = ei1.Coordinate;
}
return(new Edge(pts, new Label(edge.Label)));
}
/// <summary>
/// Adds an intersection into the list, if it isn't already there.
/// The input segmentIndex and dist are expected to be normalized.
/// </summary>
/// <param name="intPt"></param>
/// <param name="segmentIndex"></param>
/// <param name="dist"></param>
/// <returns>The EdgeIntersection found or added.</returns>
public EdgeIntersection Add(Coordinate intPt, int segmentIndex, double dist)
{
var eiNew = new EdgeIntersection(intPt, segmentIndex, dist);
EdgeIntersection ei;
if (nodeMap.TryGetValue(eiNew, out ei))
{
return(ei);
}
nodeMap[eiNew] = eiNew;
return(eiNew);
}
