示例#1
0
  /**
   * Inserted edges are checked to see if an identical edge already exists. If so, the edge is not
   * inserted, but its label is merged with the existing edge.
   */
  protected void insertUniqueEdge(Edge e) {
    // <FIX> MD 8 Oct 03  speed up identical edge lookup
    // fast lookup
    Edge existingEdge = edgeList.findEqualEdge(e);

    // If an identical edge already exists, simply update its label
    if (existingEdge != null) {
      Label existingLabel = existingEdge.getLabel();

      Label labelToMerge = e.getLabel();
      // check if new edge is in reverse direction to existing edge
      // if so, must flip the label before merging it
      if (!existingEdge.isPointwiseEqual(e)) {
        labelToMerge = new Label(e.getLabel());
        labelToMerge.flip();
      }
      existingLabel.merge(labelToMerge);

      // compute new depth delta of sum of edges
      int mergeDelta = depthDelta(labelToMerge);
      int existingDelta = existingEdge.getDepthDelta();
      int newDelta = existingDelta + mergeDelta;
      existingEdge.setDepthDelta(newDelta);
    } else { // no matching existing edge was found
      // add this new edge to the list of edges in this graph
      // e.setName(name + edges.size());
      edgeList.add(e);
      e.setDepthDelta(depthDelta(e.getLabel()));
    }
  }
示例#2
0
  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;
  }