use of org.opensphere.geometry.triangulation.model.Triangle in project OpenTripPlanner by opentripplanner.
the class ConcaveHull method concaveHull.
/**
* Create the concave hull.
*
* @return
* the concave hull
*/
private Geometry concaveHull() {
// triangulation: create a DelaunayTriangulationBuilder object
ConformingDelaunayTriangulationBuilder cdtb = new ConformingDelaunayTriangulationBuilder();
// add geometry collection
cdtb.setSites(this.geometries);
QuadEdgeSubdivision qes = cdtb.getSubdivision();
Collection<QuadEdge> quadEdges = qes.getEdges();
List<QuadEdgeTriangle> qeTriangles = QuadEdgeTriangle.createOn(qes);
Collection<com.vividsolutions.jts.triangulate.quadedge.Vertex> qeVertices = qes.getVertices(false);
int iV = 0;
for (com.vividsolutions.jts.triangulate.quadedge.Vertex v : qeVertices) {
this.coordinates.put(v.getCoordinate(), iV);
this.vertices.put(iV, new Vertex(iV, v.getCoordinate()));
iV++;
}
// border
List<QuadEdge> qeFrameBorder = new ArrayList<QuadEdge>();
List<QuadEdge> qeFrame = new ArrayList<QuadEdge>();
List<QuadEdge> qeBorder = new ArrayList<QuadEdge>();
for (QuadEdge qe : quadEdges) {
if (qes.isFrameBorderEdge(qe)) {
qeFrameBorder.add(qe);
}
if (qes.isFrameEdge(qe)) {
qeFrame.add(qe);
}
}
// border
for (int j = 0; j < qeFrameBorder.size(); j++) {
QuadEdge q = qeFrameBorder.get(j);
if (!qeFrame.contains(q)) {
qeBorder.add(q);
}
}
// deletion of exterior edges
for (QuadEdge qe : qeFrame) {
qes.delete(qe);
}
HashMap<QuadEdge, Double> qeDistances = new HashMap<QuadEdge, Double>();
for (QuadEdge qe : quadEdges) {
qeDistances.put(qe, qe.toLineSegment().getLength());
}
DoubleComparator dc = new DoubleComparator(qeDistances);
TreeMap<QuadEdge, Double> qeSorted = new TreeMap<QuadEdge, Double>(dc);
qeSorted.putAll(qeDistances);
// edges creation
int i = 0;
for (QuadEdge qe : qeSorted.keySet()) {
LineSegment s = qe.toLineSegment();
s.normalize();
Integer idS = this.coordinates.get(s.p0);
Integer idD = this.coordinates.get(s.p1);
Vertex oV = this.vertices.get(idS);
Vertex eV = this.vertices.get(idD);
Edge edge;
if (qeBorder.contains(qe)) {
oV.setBorder(true);
eV.setBorder(true);
edge = new Edge(i, s, oV, eV, true);
if (s.getLength() < this.threshold) {
this.shortLengths.put(i, edge);
} else {
this.lengths.put(i, edge);
}
} else {
edge = new Edge(i, s, oV, eV, false);
}
this.edges.put(i, edge);
this.segments.put(s, i);
i++;
}
// hm of linesegment and hm of edges // with id as key
// hm of triangles using hm of ls and connection with hm of edges
i = 0;
for (QuadEdgeTriangle qet : qeTriangles) {
LineSegment sA = qet.getEdge(0).toLineSegment();
LineSegment sB = qet.getEdge(1).toLineSegment();
LineSegment sC = qet.getEdge(2).toLineSegment();
sA.normalize();
sB.normalize();
sC.normalize();
Edge edgeA = this.edges.get(this.segments.get(sA));
Edge edgeB = this.edges.get(this.segments.get(sB));
Edge edgeC = this.edges.get(this.segments.get(sC));
if (edgeA == null || edgeB == null || edgeC == null)
continue;
Triangle triangle = new Triangle(i, qet.isBorder() ? true : false);
triangle.addEdge(edgeA);
triangle.addEdge(edgeB);
triangle.addEdge(edgeC);
edgeA.addTriangle(triangle);
edgeB.addTriangle(triangle);
edgeC.addTriangle(triangle);
this.triangles.put(i, triangle);
i++;
}
// add triangle neighbourood
for (Edge edge : this.edges.values()) {
if (edge.getTriangles().size() > 1) {
Triangle tA = edge.getTriangles().get(0);
Triangle tB = edge.getTriangles().get(1);
tA.addNeighbour(tB);
tB.addNeighbour(tA);
}
}
// concave hull algorithm
int index = 0;
while (index != -1) {
index = -1;
Edge e = null;
// find the max length (smallest id so first entry)
int si = this.lengths.size();
if (si != 0) {
Entry<Integer, Edge> entry = this.lengths.firstEntry();
int ind = entry.getKey();
if (entry.getValue().getGeometry().getLength() > this.threshold) {
index = ind;
e = entry.getValue();
}
}
if (index != -1) {
Triangle triangle = e.getTriangles().get(0);
List<Triangle> neighbours = triangle.getNeighbours();
// irregular triangle test
if (neighbours.size() == 1) {
this.shortLengths.put(e.getId(), e);
this.lengths.remove(e.getId());
} else {
Edge e0 = triangle.getEdges().get(0);
Edge e1 = triangle.getEdges().get(1);
// test if all the vertices are on the border
if (e0.getOV().isBorder() && e0.getEV().isBorder() && e1.getOV().isBorder() && e1.getEV().isBorder()) {
this.shortLengths.put(e.getId(), e);
this.lengths.remove(e.getId());
} else {
// not sure this is safe
if (neighbours.size() < 1)
continue;
Triangle tA = neighbours.get(0);
Triangle tB = neighbours.get(1);
// FIXME not necessarily useful
tA.setBorder(true);
// FIXME not necessarily useful
tB.setBorder(true);
this.triangles.remove(triangle.getId());
tA.removeNeighbour(triangle);
tB.removeNeighbour(triangle);
// new edges
List<Edge> ee = triangle.getEdges();
Edge eA = ee.get(0);
Edge eB = ee.get(1);
Edge eC = ee.get(2);
if (eA.isBorder()) {
this.edges.remove(eA.getId());
eB.setBorder(true);
eB.getOV().setBorder(true);
eB.getEV().setBorder(true);
eC.setBorder(true);
eC.getOV().setBorder(true);
eC.getEV().setBorder(true);
// clean the relationships with the triangle
eB.removeTriangle(triangle);
eC.removeTriangle(triangle);
if (eB.getGeometry().getLength() < this.threshold) {
this.shortLengths.put(eB.getId(), eB);
} else {
this.lengths.put(eB.getId(), eB);
}
if (eC.getGeometry().getLength() < this.threshold) {
this.shortLengths.put(eC.getId(), eC);
} else {
this.lengths.put(eC.getId(), eC);
}
this.lengths.remove(eA.getId());
} else if (eB.isBorder()) {
this.edges.remove(eB.getId());
eA.setBorder(true);
eA.getOV().setBorder(true);
eA.getEV().setBorder(true);
eC.setBorder(true);
eC.getOV().setBorder(true);
eC.getEV().setBorder(true);
// clean the relationships with the triangle
eA.removeTriangle(triangle);
eC.removeTriangle(triangle);
if (eA.getGeometry().getLength() < this.threshold) {
this.shortLengths.put(eA.getId(), eA);
} else {
this.lengths.put(eA.getId(), eA);
}
if (eC.getGeometry().getLength() < this.threshold) {
this.shortLengths.put(eC.getId(), eC);
} else {
this.lengths.put(eC.getId(), eC);
}
this.lengths.remove(eB.getId());
} else {
this.edges.remove(eC.getId());
eA.setBorder(true);
eA.getOV().setBorder(true);
eA.getEV().setBorder(true);
eB.setBorder(true);
eB.getOV().setBorder(true);
eB.getEV().setBorder(true);
// clean the relationships with the triangle
eA.removeTriangle(triangle);
eB.removeTriangle(triangle);
if (eA.getGeometry().getLength() < this.threshold) {
this.shortLengths.put(eA.getId(), eA);
} else {
this.lengths.put(eA.getId(), eA);
}
if (eB.getGeometry().getLength() < this.threshold) {
this.shortLengths.put(eB.getId(), eB);
} else {
this.lengths.put(eB.getId(), eB);
}
this.lengths.remove(eC.getId());
}
}
}
}
}
// concave hull creation
List<LineString> edges = new ArrayList<LineString>();
for (Edge e : this.lengths.values()) {
LineString l = e.getGeometry().toGeometry(this.geomFactory);
edges.add(l);
}
for (Edge e : this.shortLengths.values()) {
LineString l = e.getGeometry().toGeometry(this.geomFactory);
edges.add(l);
}
// merge
LineMerger lineMerger = new LineMerger();
lineMerger.add(edges);
LineString merge = (LineString) lineMerger.getMergedLineStrings().iterator().next();
if (merge.isRing()) {
LinearRing lr = new LinearRing(merge.getCoordinateSequence(), this.geomFactory);
Polygon concaveHull = new Polygon(lr, null, this.geomFactory);
return concaveHull;
}
return merge;
}
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