/** decimates JTS geometries. */
public final Geometry decimate(Geometry geom) {
GeometryFactory gFac = new GeometryFactory(geom.getPrecisionModel(), geom.getSRID());
if (spanx == -1) return geom;
if (geom instanceof MultiPoint) {
// TODO check geometry and if its bbox is too small turn it into a 1
// point geom
return geom;
}
if (geom instanceof GeometryCollection) {
// TODO check geometry and if its bbox is too small turn it into a
// 1-2 point geom
// takes a bit of work because the geometry will need to be
// recreated.
GeometryCollection collection = (GeometryCollection) geom;
Geometry[] result = new Geometry[collection.getDimension()];
final int numGeometries = collection.getNumGeometries();
for (int i = 0; i < numGeometries; i++) {
result[i] = decimate(collection.getGeometryN(i));
}
return gFac.createGeometryCollection(result);
} else if (geom instanceof LineString) {
LineString line = (LineString) geom;
CoordinateSequence seq = (CoordinateSequence) line.getCoordinateSequence();
LiteCoordinateSequence lseq = new LiteCoordinateSequence(seq.toCoordinateArray());
if (decimateOnEnvelope(line, lseq)) {
if (lseq.size() >= 2) return gFac.createLineString(lseq);
}
if (lseq.size() >= 2) return gFac.createLineString(decimate(lseq));
return null;
} else if (geom instanceof Polygon) {
Polygon line = (Polygon) geom;
Coordinate[] exterior = decimate(line.getExteriorRing()).getCoordinates();
forceClosed(exterior);
if (exterior.length > 3) {
LinearRing ring = gFac.createLinearRing(exterior);
final int numRings = line.getNumInteriorRing();
List<LinearRing> rings = new ArrayList<LinearRing>();
for (int i = 0; i < numRings; i++) {
Coordinate[] interior = decimate(line.getInteriorRingN(i)).getCoordinates();
forceClosed(interior);
if (interior.length > 3) rings.add(gFac.createLinearRing(interior));
}
return gFac.createPolygon(ring, rings.toArray(new LinearRing[] {}));
}
return null;
}
return geom;
}
public Geometry buffer(Geometry g, double distance) {
PrecisionModel precisionModel = workingPrecisionModel;
if (precisionModel == null) precisionModel = g.getPrecisionModel();
// factory must be the same as the one used by the input
geomFact = g.getFactory();
OffsetCurveBuilder curveBuilder = new OffsetCurveBuilder(precisionModel, bufParams);
OffsetCurveSetBuilder curveSetBuilder = new OffsetCurveSetBuilder(g, distance, curveBuilder);
List bufferSegStrList = curveSetBuilder.getCurves();
// short-circuit test
if (bufferSegStrList.size() <= 0) {
return createEmptyResultGeometry();
}
// BufferDebug.runCount++;
// String filename = "run" + BufferDebug.runCount + "_curves";
// System.out.println("saving " + filename);
// BufferDebug.saveEdges(bufferEdgeList, filename);
// DEBUGGING ONLY
// WKTWriter wktWriter = new WKTWriter();
// Debug.println("Rings: " + wktWriter.write(convertSegStrings(bufferSegStrList.iterator())));
// wktWriter.setMaxCoordinatesPerLine(10);
// System.out.println(wktWriter.writeFormatted(convertSegStrings(bufferSegStrList.iterator())));
computeNodedEdges(bufferSegStrList, precisionModel);
graph = new PlanarGraph(new OverlayNodeFactory());
graph.addEdges(edgeList.getEdges());
List subgraphList = createSubgraphs(graph);
PolygonBuilder polyBuilder = new PolygonBuilder(geomFact);
buildSubgraphs(subgraphList, polyBuilder);
List resultPolyList = polyBuilder.getPolygons();
// just in case...
if (resultPolyList.size() <= 0) {
return createEmptyResultGeometry();
}
Geometry resultGeom = geomFact.buildGeometry(resultPolyList);
return resultGeom;
}
