1 /*
2 * Copyright (C) 2017 Alberto Irurueta Carro (alberto@irurueta.com)
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.irurueta.geometry;
18
19 import java.io.Serializable;
20
21 /**
22 * Abstract representation of a box for a point in an n-dimensional representation.
23 *
24 * @param <P> a point implementation.
25 */
26 public abstract class Box<P extends Point<P>> implements Serializable {
27
28 /**
29 * Low coordinate values.
30 */
31 protected P lo;
32
33 /**
34 * High coordinate values.
35 */
36 protected P hi;
37
38 /**
39 * Empty constructor.
40 */
41 protected Box() {
42 }
43
44 /**
45 * Constructor.
46 *
47 * @param lo low coordinate values.
48 * @param hi high coordinate values.
49 */
50 protected Box(final P lo, final P hi) {
51 internalSetBounds(lo, hi);
52 }
53
54 /**
55 * Gets low coordinate values.
56 *
57 * @return low coordinate values.
58 */
59 public P getLo() {
60 return lo;
61 }
62
63 /**
64 * Sets low coordinate values.
65 *
66 * @param lo low coordinate values.
67 */
68 public void setLo(final P lo) {
69 this.lo = lo;
70 }
71
72 /**
73 * Gets high coordinate values.
74 *
75 * @return high coordinate values.
76 */
77 public P getHi() {
78 return hi;
79 }
80
81 /**
82 * Sets high coordinate values.
83 *
84 * @param hi high coordinate values.
85 */
86 public void setHi(final P hi) {
87 this.hi = hi;
88 }
89
90 /**
91 * Sets boundaries.
92 *
93 * @param lo low coordinate values.
94 * @param hi high coordinate values.
95 */
96 public void setBounds(final P lo, final P hi) {
97 internalSetBounds(lo, hi);
98 }
99
100 /**
101 * Gets square distance of provided point to the boundaries of this box or zero if the point is
102 * inside this box.
103 *
104 * @param point point to be checked.
105 * @return distance of provided point.
106 */
107 public double getSqrDistance(final P point) {
108 final var dim = point.getDimensions();
109
110 var dd = 0.0;
111 for (var i = 0; i < dim; i++) {
112 final var pointValue = point.getInhomogeneousCoordinate(i);
113 final var loValue = lo.getInhomogeneousCoordinate(i);
114 final var hiValue = hi.getInhomogeneousCoordinate(i);
115
116 if (pointValue < loValue) {
117 dd += sqr(pointValue - loValue);
118 }
119 if (pointValue > hiValue) {
120 dd += sqr(pointValue - hiValue);
121 }
122 }
123 return dd;
124 }
125
126 /**
127 * Gets distance of provided point to the boundaries of this box or zero if the point is
128 * inside this box.
129 *
130 * @param point point to be checked.
131 * @return distance of provided point.
132 */
133 public double getDistance(final P point) {
134 return Math.sqrt(getSqrDistance(point));
135 }
136
137 /**
138 * Returns the squared value.
139 *
140 * @param value value to be squared.
141 * @return squared value.
142 */
143 private double sqr(final double value) {
144 return value * value;
145 }
146
147 /**
148 * Internally sets boundaries.
149 *
150 * @param lo low coordinate values.
151 * @param hi high coordinate values.
152 */
153 private void internalSetBounds(final P lo, final P hi) {
154 this.lo = lo;
155 this.hi = hi;
156 }
157 }