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