public static LineString removeRepeatedPoints(final LineString points) {
final int axisCount = points.getAxisCount();
final List<Double> coordinates = new ArrayList<>();
double x = points.getX(0);
double y = points.getY(0);
coordinates.add(x);
coordinates.add(y);
for (int axisIndex = 2; axisIndex < axisCount; axisIndex++) {
coordinates.add(points.getCoordinate(0, axisIndex));
}
for (int i = 0; i < points.getVertexCount(); i++) {
final double x1 = points.getX(i);
final double y1 = points.getY(i);
if (x != x1 || y != y1) {
coordinates.add(x1);
coordinates.add(y1);
for (int axisIndex = 2; axisIndex < axisCount; axisIndex++) {
coordinates.add(points.getCoordinate(i, axisIndex));
}
x = x1;
y = y1;
}
}
return new LineStringDouble(axisCount, coordinates);
}
public static List<LineString> intersection(
final GeometryFactory geometryFactory,
final LineString points1,
final LineString points2,
final double maxDistance) {
final LineStringGraph graph1 = new LineStringGraph(points1);
graph1.setPrecisionModel(geometryFactory);
final LineStringGraph graph2 = new LineStringGraph(points2);
graph2.setPrecisionModel(geometryFactory);
final Map<Point, Point> movedNodes = new HashMap<>();
graph1.forEachNode((node) -> movePointsWithinTolerance(movedNodes, graph2, maxDistance, node));
graph2.forEachNode((node) -> movePointsWithinTolerance(movedNodes, graph1, maxDistance, node));
final Map<Edge<LineSegment>, List<Node<LineSegment>>> pointsOnEdge1 =
graph1.getPointsOnEdges(graph2, maxDistance);
final Map<Edge<LineSegment>, List<Node<LineSegment>>> pointsOnEdge2 =
graph2.getPointsOnEdges(graph1, maxDistance);
graph1.splitEdges(pointsOnEdge1);
graph2.splitEdges(pointsOnEdge2);
Point startPoint = points1.getPoint(0);
if (movedNodes.containsKey(startPoint)) {
startPoint = movedNodes.get(startPoint);
}
Point endPoint = points1.getPoint(points1.getVertexCount() - 1);
if (movedNodes.containsKey(endPoint)) {
endPoint = movedNodes.get(endPoint);
}
final List<LineString> intersections = new ArrayList<>();
final List<Point> currentCoordinates = new ArrayList<>();
Node<LineSegment> previousNode = graph1.getNode(startPoint);
do {
final List<Edge<LineSegment>> outEdges = previousNode.getOutEdges();
if (outEdges.isEmpty()) {
previousNode = null;
} else if (outEdges.size() > 1) {
throw new IllegalArgumentException("Cannot handle overlaps\n" + points1 + "\n " + points2);
} else {
final Edge<LineSegment> edge = outEdges.get(0);
final LineSegment line = edge.getObject();
final Node<LineSegment> nextNode = edge.getToNode();
if (graph2.hasEdgeBetween(previousNode, nextNode)) {
if (currentCoordinates.size() == 0) {
currentCoordinates.add(line.getPoint(0));
}
currentCoordinates.add(line.getPoint(1));
} else {
if (currentCoordinates.size() > 0) {
final LineString points =
new LineStringDouble(points1.getAxisCount(), currentCoordinates);
intersections.add(points);
currentCoordinates.clear();
}
}
previousNode = nextNode;
}
} while (previousNode != null && !endPoint.equals(2, startPoint));
if (currentCoordinates.size() > 0) {
final LineString points = new LineStringDouble(points1.getAxisCount(), currentCoordinates);
intersections.add(points);
}
return intersections;
}