Exemplo n.º 1
0
        /// <summary>
        ///
        /// </summary>
        /// <param name="opCode"></param>
        private void ComputeOverlay(SpatialFunctions opCode)
        {
            // copy points from input Geometries.
            // This ensures that any Point geometries
            // in the input are considered for inclusion in the result set
            CopyPoints(0);
            CopyPoints(1);

            // node the input Geometries
            arg[0].ComputeSelfNodes(lineIntersector, false);
            arg[1].ComputeSelfNodes(lineIntersector, false);

            // compute intersections between edges of the two input geometries
            arg[0].ComputeEdgeIntersections(arg[1], lineIntersector, true);

            IList baseSplitEdges = new ArrayList();

            arg[0].ComputeSplitEdges(baseSplitEdges);
            arg[1].ComputeSplitEdges(baseSplitEdges);
            // add the noded edges to this result graph
            InsertUniqueEdges(baseSplitEdges);

            ComputeLabelsFromDepths();
            ReplaceCollapsedEdges();

            graph.AddEdges(edgeList.Edges);
            ComputeLabelling();
            LabelIncompleteNodes();

            /*
             * The ordering of building the result Geometries is important.
             * Areas must be built before lines, which must be built before points.
             * This is so that lines which are covered by areas are not included
             * explicitly, and similarly for points.
             */
            FindResultAreaEdges(opCode);
            CancelDuplicateResultEdges();
            PolygonBuilder polyBuilder = new PolygonBuilder(geomFact);

            polyBuilder.Add(graph);
            resultPolyList = polyBuilder.Polygons;

            LineBuilder lineBuilder = new LineBuilder(this, geomFact, ptLocator);

            resultLineList = lineBuilder.Build(opCode);

            PointBuilder pointBuilder = new PointBuilder(this, geomFact, ptLocator);

            resultPointList = pointBuilder.Build(opCode);

            // gather the results from all calculations into a single Geometry for the result set
            resultGeom = ComputeGeometry(resultPointList, resultLineList, resultPolyList);
        }
Exemplo n.º 2
0
        /// <summary>
        /// 
        /// </summary>
        /// <param name="g"></param>
        /// <param name="distance"></param>
        /// <returns></returns>
        public IGeometry Buffer(IGeometry g, double distance)
        {
            IPrecisionModel precisionModel = workingPrecisionModel;
            if (precisionModel == null)
                precisionModel = g.PrecisionModel;

            // factory must be the same as the one used by the input
            geomFact = g.Factory;

            OffsetCurveBuilder curveBuilder = new OffsetCurveBuilder(precisionModel, quadrantSegments);
            curveBuilder.EndCapStyle = endCapStyle;
            OffsetCurveSetBuilder curveSetBuilder = new OffsetCurveSetBuilder(g, distance, curveBuilder);

            IList bufferSegStrList = curveSetBuilder.GetCurves();

            // short-circuit test
            if (bufferSegStrList.Count <= 0)
            {
                IGeometry emptyGeom = geomFact.CreateGeometryCollection(new IGeometry[0]);
                return emptyGeom;
            }

            ComputeNodedEdges(bufferSegStrList, precisionModel);
            graph = new PlanarGraph(new OverlayNodeFactory());
            graph.AddEdges(edgeList.Edges);

            IList subgraphList = CreateSubgraphs(graph);
            PolygonBuilder polyBuilder = new PolygonBuilder(geomFact);
            BuildSubgraphs(subgraphList, polyBuilder);
            IList resultPolyList = polyBuilder.Polygons;

            IGeometry resultGeom = geomFact.BuildGeometry(resultPolyList);
            return resultGeom;
        }
Exemplo n.º 3
0
 /// <summary>
 /// Completes the building of the input subgraphs by depth-labelling them,
 /// and adds them to the <see cref="PolygonBuilder" />.
 /// The subgraph list must be sorted in rightmost-coordinate order.
 /// </summary>
 /// <param name="subgraphList">The subgraphs to build.</param>
 /// <param name="polyBuilder">The PolygonBuilder which will build the final polygons.</param>
 private void BuildSubgraphs(IList subgraphList, PolygonBuilder polyBuilder)
 {
     IList processedGraphs = new ArrayList();
     foreach(object obj in subgraphList)
     {
         BufferSubgraph subgraph = (BufferSubgraph)obj;
         ICoordinate p = subgraph.RightMostCoordinate;
         SubgraphDepthLocater locater = new SubgraphDepthLocater(processedGraphs);
         int outsideDepth = locater.GetDepth(p);
         subgraph.ComputeDepth(outsideDepth);
         subgraph.FindResultEdges();
         processedGraphs.Add(subgraph);
         polyBuilder.Add(subgraph.DirectedEdges, subgraph.Nodes);
     }
 }
Exemplo n.º 4
0
        /// <summary>
        /// 
        /// </summary>
        /// <param name="opCode"></param>
        private void ComputeOverlay(SpatialFunctions opCode)
        {
            // copy points from input Geometries.
            // This ensures that any Point geometries
            // in the input are considered for inclusion in the result set
            CopyPoints(0);
            CopyPoints(1);

            // node the input Geometries
            arg[0].ComputeSelfNodes(lineIntersector, false);
            arg[1].ComputeSelfNodes(lineIntersector, false);

            // compute intersections between edges of the two input geometries
            arg[0].ComputeEdgeIntersections(arg[1], lineIntersector, true);

            IList baseSplitEdges = new ArrayList();
            arg[0].ComputeSplitEdges(baseSplitEdges);
            arg[1].ComputeSplitEdges(baseSplitEdges);
            // add the noded edges to this result graph
            InsertUniqueEdges(baseSplitEdges);

            ComputeLabelsFromDepths();
            ReplaceCollapsedEdges();

            graph.AddEdges(edgeList.Edges);
            ComputeLabelling();
            LabelIncompleteNodes();

            /*
            * The ordering of building the result Geometries is important.
            * Areas must be built before lines, which must be built before points.
            * This is so that lines which are covered by areas are not included
            * explicitly, and similarly for points.
            */
            FindResultAreaEdges(opCode);
            CancelDuplicateResultEdges();
            PolygonBuilder polyBuilder = new PolygonBuilder(geomFact);
            polyBuilder.Add(graph);
            resultPolyList = polyBuilder.Polygons;

            LineBuilder lineBuilder = new LineBuilder(this, geomFact, ptLocator);
            resultLineList = lineBuilder.Build(opCode);

            PointBuilder pointBuilder = new PointBuilder(this, geomFact, ptLocator);
            resultPointList = pointBuilder.Build(opCode);

            // gather the results from all calculations into a single Geometry for the result set
            resultGeom = ComputeGeometry(resultPointList, resultLineList, resultPolyList);
        }