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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.io.euclidean;
18  
19  import java.nio.file.Path;
20  import java.nio.file.Paths;
21  import java.util.stream.Stream;
22  
23  import org.apache.commons.geometry.euclidean.EuclideanTestUtils;
24  import org.apache.commons.geometry.euclidean.threed.AffineTransformMatrix3D;
25  import org.apache.commons.geometry.euclidean.threed.RegionBSPTree3D;
26  import org.apache.commons.geometry.euclidean.threed.Triangle3D;
27  import org.apache.commons.geometry.euclidean.threed.Vector3D;
28  import org.apache.commons.geometry.euclidean.threed.mesh.TriangleMesh;
29  import org.apache.commons.geometry.euclidean.threed.shape.Parallelepiped;
30  import org.apache.commons.geometry.euclidean.threed.shape.Sphere;
31  import org.apache.commons.geometry.io.core.input.FileGeometryInput;
32  import org.apache.commons.geometry.io.core.input.GeometryInput;
33  import org.apache.commons.geometry.io.core.output.FileGeometryOutput;
34  import org.apache.commons.geometry.io.core.output.GeometryOutput;
35  import org.apache.commons.geometry.io.euclidean.threed.IO3D;
36  import org.apache.commons.numbers.core.Precision;
37  import org.junit.jupiter.api.Assertions;
38  import org.junit.jupiter.api.Test;
39  import org.junit.jupiter.api.io.TempDir;
40  
41  class DocumentationExamplesTest {
42  
43      private static final double TEST_EPS = 1e-12;
44  
45      @TempDir
46      Path tempDir;
47  
48      @Test
49      void testIndexPageExample() {
50          // construct a precision instance to handle floating-point comparisons
51          final Precision.DoubleEquivalence precision = Precision.doubleEquivalenceOfEpsilon(1e-6);
52  
53          // create a BSP tree representing the unit cube
54          final RegionBSPTree3D tree = Parallelepiped.unitCube(precision).toTree();
55  
56          // create a sphere centered on the origin
57          final Sphere sphere = Sphere.from(Vector3D.ZERO, 0.65, precision);
58  
59          // subtract a BSP tree approximation of the sphere containing 512 facets
60          // from the cube, modifying the cube tree in place
61          tree.difference(sphere.toTree(3));
62  
63          // compute some properties of the resulting region
64          final double size = tree.getSize(); // 0.11509505362599505
65          final Vector3D centroid = tree.getCentroid(); // (0, 0, 0)
66  
67          // convert to a triangle mesh
68          final TriangleMesh mesh = tree.toTriangleMesh(precision);
69  
70          // save as an OBJ file
71          IO3D.write(mesh, Paths.get("target/cube-minus-sphere.obj"));
72  
73          // -----------
74          Assertions.assertEquals(0.11509505362599505, size, TEST_EPS);
75          EuclideanTestUtils.assertCoordinatesEqual(Vector3D.ZERO, centroid, TEST_EPS);
76      }
77  
78      @Test
79      void testIO3DExample() throws Exception {
80  
81          final Path inputPath = Paths.get(EuclideanIOTestUtils.resource("/models/cube.obj").toURI());
82          final Path outputPath = tempDir.resolve("scaled.csv");
83  
84          final Precision.DoubleEquivalence precision = Precision.doubleEquivalenceOfEpsilon(1e-6);
85  
86          final GeometryInput input = new FileGeometryInput(inputPath);
87          final GeometryOutput scaledOutput = new FileGeometryOutput(outputPath);
88          final AffineTransformMatrix3D transform = AffineTransformMatrix3D.createScale(2);
89  
90          // Use the input triangle stream in a try-with-resources statement to ensure
91          // all resources are properly released.
92          try (Stream<Triangle3D> stream = IO3D.triangles(input, null, precision)) {
93              IO3D.write(stream.map(t -> t.transform(transform)), scaledOutput, null);
94          }
95  
96          // -------------
97          final RegionBSPTree3D result = IO3D.read(outputPath, precision).toTree();
98  
99          Assertions.assertEquals(8.0, result.getSize(), TEST_EPS);
100 
101     }
102 }