protected override Coordinate ExtractOffsetAt(IGeometry linearGeom, Coordinate testPt, double offsetDistance)
{
LocationIndexedLine indexedLine = new LocationIndexedLine(linearGeom);
LinearLocation index = indexedLine.IndexOf(testPt);
return indexedLine.ExtractPoint(index, offsetDistance);
}
protected override bool IndexOfAfterCheck(IGeometry linearGeom, Coordinate testPt)
{
LocationIndexedLine indexedLine = new LocationIndexedLine(linearGeom);
// check locations are consecutive
LinearLocation loc1 = indexedLine.IndexOf(testPt);
LinearLocation loc2 = indexedLine.IndexOfAfter(testPt, loc1);
if (loc2.CompareTo(loc1) <= 0) return false;
// check extracted points are the same as the input
Coordinate pt1 = indexedLine.ExtractPoint(loc1);
Coordinate pt2 = indexedLine.ExtractPoint(loc2);
if (!pt1.Equals2D(testPt)) return false;
if (!pt2.Equals2D(testPt)) return false;
return true;
}