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.threed.line;
18
19 import java.util.ArrayList;
20 import java.util.Comparator;
21 import java.util.List;
22 import java.util.ListIterator;
23
24 import org.apache.commons.geometry.euclidean.AbstractLinecastPoint;
25 import org.apache.commons.geometry.euclidean.threed.Vector3D;
26 import org.apache.commons.numbers.core.Precision;
27
28 /** Class representing intersections resulting from linecast operations in Euclidean
29 * 3D space. This class contains the intersection point along with the boundary normal
30 * of the target at the point of intersection.
31 * @see Linecastable3D
32 */
33 public class LinecastPoint3D extends AbstractLinecastPoint<Vector3D, Vector3D.Unit, Line3D> {
34
35 /** Comparator that sorts intersection instances by increasing abscissa order. If two abscissa
36 * values are equal, the comparison uses {@link Vector3D#COORDINATE_ASCENDING_ORDER} with the
37 * intersection normals.
38 */
39 public static final Comparator<LinecastPoint3D> ABSCISSA_ORDER = (a, b) -> {
40 int cmp = Double.compare(a.getAbscissa(), b.getAbscissa());
41 if (cmp == 0) {
42 cmp = Vector3D.COORDINATE_ASCENDING_ORDER.compare(a.getNormal(), b.getNormal());
43 }
44 return cmp;
45 };
46
47 /** Construct a new instance from its components.
48 * @param point intersection point
49 * @param normal normal of the target boundary at the intersection point
50 * @param line intersecting line
51 */
52 public LinecastPoint3D(final Vector3D point, final Vector3D normal, final Line3D line) {
53 super(point, normal.normalize(), line);
54 }
55
56 /** Return true if this instance should be considered equivalent to the argument, using the
57 * given precision context for comparison. Instances are considered equivalent if they have
58 * equivalent points, normals, and lines.
59 * @param other other point to compare with
60 * @param precision context to use for the comparison
61 * @return true if this instance should be considered equivalent to the argument
62 */
63 public boolean eq(final LinecastPoint3D other, final Precision.DoubleEquivalence precision) {
64 return getLine().eq(other.getLine(), precision) &&
65 getPoint().eq(other.getPoint(), precision) &&
66 getNormal().eq(other.getNormal(), precision);
67 }
68
69 /** Sort the given list of linecast points by increasing abscissa value and filter to remove
70 * duplicate entries (as determined by the {@link #eq(LinecastPoint3D, Precision.DoubleEquivalence)} method).
71 * The argument is modified.
72 * @param pts list of points to sort and filter
73 */
74 public static void sortAndFilter(final List<LinecastPoint3D> pts) {
75 pts.sort(ABSCISSA_ORDER);
76
77 double currentAbscissa = Double.POSITIVE_INFINITY;
78 final List<LinecastPoint3D> abscissaList = new ArrayList<>();
79
80 final ListIterator<LinecastPoint3D> it = pts.listIterator();
81 LinecastPoint3D pt;
82 while (it.hasNext()) {
83 pt = it.next();
84 if (!pt.getLine().getPrecision().eq(currentAbscissa, pt.getAbscissa())) {
85 // new abscissa value
86 currentAbscissa = pt.getAbscissa();
87 abscissaList.clear();
88
89 abscissaList.add(pt);
90 } else if (containsEq(pt, abscissaList)) {
91 // duplicate found for this abscissa value
92 it.remove();
93 } else {
94 // not a duplicate
95 abscissaList.add(pt);
96 }
97 }
98 }
99
100 /** Return true if the given linecast point is equivalent to any of those in the given list.
101 * @param pt point to test
102 * @param list list to test against
103 * @return true if the given linecast point is equivalent to any of those in the given list
104 */
105 private static boolean containsEq(final LinecastPoint3D pt, final List<? extends LinecastPoint3D> list) {
106 final Precision.DoubleEquivalence precision = pt.getLine().getPrecision();
107
108 for (final LinecastPoint3D listPt : list) {
109 if (listPt.eq(pt, precision)) {
110 return true;
111 }
112 }
113
114 return false;
115 }
116 }