/** Splits the input geometry into two LineStrings at the given point. */
public static P2<LineString> splitGeometryAtPoint(Geometry geometry, Coordinate nearestPoint) {
// An index in JTS can actually refer to any point along the line. It is NOT an array index.
LocationIndexedLine line = new LocationIndexedLine(geometry);
LinearLocation l = line.indexOf(nearestPoint);
LineString beginning = (LineString) line.extractLine(line.getStartIndex(), l);
LineString ending = (LineString) line.extractLine(l, line.getEndIndex());
return new P2<LineString>(beginning, ending);
}
/** Splits the input geometry into two LineStrings at a fraction of the distance covered. */
public static P2<LineString> splitGeometryAtFraction(Geometry geometry, double fraction) {
LineString empty = new LineString(null, gf);
Coordinate[] coordinates = geometry.getCoordinates();
CoordinateSequence sequence = gf.getCoordinateSequenceFactory().create(coordinates);
LineString total = new LineString(sequence, gf);
if (coordinates.length < 2) return new P2<LineString>(empty, empty);
if (fraction <= 0) return new P2<LineString>(empty, total);
if (fraction >= 1) return new P2<LineString>(total, empty);
double totalDistance = total.getLength();
double requestedDistance = totalDistance * fraction;
// An index in JTS can actually refer to any point along the line. It is NOT an array index.
LocationIndexedLine line = new LocationIndexedLine(geometry);
LinearLocation l = LengthLocationMap.getLocation(geometry, requestedDistance);
LineString beginning = (LineString) line.extractLine(line.getStartIndex(), l);
LineString ending = (LineString) line.extractLine(l, line.getEndIndex());
return new P2<LineString>(beginning, ending);
}