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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.examples.tutorials.bsp;
18  
19  import java.io.File;
20  import java.util.Arrays;
21  
22  import org.apache.commons.geometry.core.precision.DoublePrecisionContext;
23  import org.apache.commons.geometry.core.precision.EpsilonDoublePrecisionContext;
24  import org.apache.commons.geometry.euclidean.twod.Bounds2D;
25  import org.apache.commons.geometry.euclidean.twod.RegionBSPTree2D;
26  import org.apache.commons.geometry.euclidean.twod.Vector2D;
27  import org.apache.commons.geometry.euclidean.twod.path.LinePath;
28  
29  /** Class containing tutorial code for computing the xor result of two trees.
30   */
31  public final class BSPTreeXor {
32  
33      /** No instantiation. */
34      private BSPTreeXor() {}
35  
36      /** Tutorial code entry point.
37       * @param args command arguments; if given, the first argument is used as the location of
38       *      output folder
39       */
40      public static void main(String[] args) {
41          File outputFolder = new File(args.length > 0 ? args[0] : ".");
42          BSPTreeSVGWriter svgWriter = new BSPTreeSVGWriter(Bounds2D.from(Vector2D.of(-8, -8), Vector2D.of(8, 8)));
43  
44          DoublePrecisionContext precision = new EpsilonDoublePrecisionContext(1e-6);
45  
46          RegionBSPTree2D result = LinePath.fromVertexLoop(Arrays.asList(
47                      Vector2D.of(2, 0),
48                      Vector2D.of(-4, 3),
49                      Vector2D.of(-4, -3)
50                  ), precision).toTree();
51  
52          RegionBSPTree2D other = LinePath.fromVertexLoop(Arrays.asList(
53                  Vector2D.of(-2, 0),
54                  Vector2D.of(4, -3),
55                  Vector2D.of(4, 3)
56              ), precision).toTree();
57  
58          result.xor(other);
59  
60          svgWriter.write(result, new File(outputFolder, "xor.svg"));
61      }
62  }