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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.geometry.euclidean.twod;
18  
19  import java.util.Arrays;
20  import java.util.Collection;
21  import java.util.List;
22  import java.util.stream.Collectors;
23  
24  import org.apache.commons.geometry.core.partitioning.BoundarySource;
25  
26  /** Extension of the {@link BoundarySource} interface for Euclidean 2D space.
27   */
28  public interface BoundarySource2D extends BoundarySource<LineConvexSubset>, Linecastable2D {
29  
30      /** Return a {@link BoundaryList2D} containing the boundaries in this instance.
31       * @return a {@link BoundaryList2D} containing the boundaries in this instance
32       */
33      default BoundaryList2D toList() {
34          final List<LineConvexSubset> boundaries = boundaryStream()
35                  .collect(Collectors.toList());
36  
37          return new BoundaryList2D(boundaries);
38      }
39  
40      /** Return a BSP tree constructed from the boundaries contained in this instance. This is
41       * a convenience method for quickly constructing BSP trees and may produce unbalanced trees
42       * with unacceptable performance characteristics when used with large numbers of boundaries.
43       * In these cases, alternate tree construction approaches should be used, such as
44       * {@link RegionBSPTree2D.PartitionedRegionBuilder2D}.
45       * @return a BSP tree constructed from the boundaries in this instance
46       * @see RegionBSPTree2D#partitionedRegionBuilder()
47       */
48      default RegionBSPTree2D toTree() {
49          final RegionBSPTree2D tree = RegionBSPTree2D.empty();
50          tree.insert(this);
51  
52          return tree;
53      }
54  
55      /** {@inheritDoc} */
56      @Override
57      default List<LinecastPoint2D> linecast(final LineConvexSubset subset) {
58          return new BoundarySourceLinecaster2D(this).linecast(subset);
59      }
60  
61      /** {@inheritDoc} */
62      @Override
63      default LinecastPoint2D linecastFirst(final LineConvexSubset subset) {
64          return new BoundarySourceLinecaster2D(this).linecastFirst(subset);
65      }
66  
67      /** Get a {@link Bounds2D} object defining the axis-aligned box containing all vertices
68       * in the boundaries for this instance. Null is returned if any boundaries are infinite
69       * or no vertices were found.
70       * @return the bounding box for this instance or null if no valid bounds could be determined
71       */
72      default Bounds2D getBounds() {
73          return new BoundarySourceBoundsBuilder2D().getBounds(this);
74      }
75  
76      /** Return a {@link BoundarySource2D} instance containing the given boundaries.
77       * @param boundaries line subsets to include in the boundary source
78       * @return a boundary source containing the given boundaries
79       */
80      static BoundarySource2D of(final LineConvexSubset... boundaries) {
81          return of(Arrays.asList(boundaries));
82      }
83  
84      /** Return a {@link BoundarySource2D} instance containing the given boundaries. The given
85       * collection is used directly as the source of the line subsets; no copy is made.
86       * @param boundaries line subsets to include in the boundary source
87       * @return a boundary source containing the given boundaries
88       */
89      static BoundarySource2D of(final Collection<LineConvexSubset> boundaries) {
90          return boundaries::stream;
91      }
92  }