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1   package org.djutils.draw.point;
2   
3   import java.util.Arrays;
4   import java.util.Iterator;
5   import java.util.Locale;
6   import java.util.Objects;
7   
8   import org.djutils.draw.Directed;
9   import org.djutils.exceptions.Throw;
10  import org.djutils.math.AngleUtil;
11  
12  /**
13   * A DirectedPoint2d is a Point2d that additionally carries a direction in 2d-space (dirZ). This is <b>not</b> the direction
14   * that the point is when viewed from the origin (0,0).
15   * <p>
16   * Copyright (c) 2023-2025 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
17   * for project information <a href="https://djutils.org" target="_blank"> https://djutils.org</a>. The DJUTILS project is
18   * distributed under a three-clause BSD-style license, which can be found at
19   * <a href="https://djutils.org/docs/license.html" target="_blank"> https://djutils.org/docs/license.html</a>.
20   * </p>
21   * @author <a href="https://www.tudelft.nl/averbraeck">Alexander Verbraeck</a>
22   * @author <a href="https://github.com/peter-knoppers">Peter Knoppers</a>
23   * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
24   */
25  public class DirectedPoint2d extends Point2d implements Directed
26  {
27      /** The counter-clockwise rotation around the point in radians. */
28      @SuppressWarnings("checkstyle:visibilitymodifier")
29      public final double dirZ;
30  
31      /**
32       * Construct a new DirectedPoint2d with an x and y coordinate and a direction.
33       * @param x the x coordinate
34       * @param y the y coordinate
35       * @param dirZ the counter-clockwise rotation around the point in radians
36       * @throws IllegalArgumentException when any coordinate or <code>dirZ</code> is <code>NaN</code>
37       */
38      public DirectedPoint2d(final double x, final double y, final double dirZ)
39      {
40          super(x, y);
41          Throw.whenNaN(dirZ, "dirZ");
42          this.dirZ = dirZ;
43      }
44  
45      /**
46       * Construct a new DirectedPoint2d from an x and y coordinates in a double[] and a direction.
47       * @param xy the <code>x</code> and <code>y</code> coordinates in that order
48       * @param dirZ the counter-clockwise rotation around the point in radians
49       * @throws NullPointerException when <code>xy</code> is <code>null</code>
50       * @throws ArithmeticException when any value in <code>xy</code> is <code>NaN</code> or <code>rotZ</code> is
51       *             <code>NaN</code>
52       * @throws IllegalArgumentException when the length of <code>xy</code> is not 2
53       */
54      public DirectedPoint2d(final double[] xy, final double dirZ)
55      {
56          super(xy);
57          Throw.whenNaN(dirZ, "dirZ");
58          this.dirZ = dirZ;
59      }
60  
61      /**
62       * Construct a new DirectedPoint2d from an AWT Point2D and a direction.
63       * @param point java.awt.geom.Point2D
64       * @param dirZ the counter-clockwise rotation around the point in radians
65       * @throws NullPointerException when <code>point</code> is <code>null</code>
66       * @throws ArithmeticException when <code>rotZ</code> is <code>NaN</code>
67       */
68      public DirectedPoint2d(final java.awt.geom.Point2D point, final double dirZ)
69      {
70          super(point);
71          Throw.whenNaN(dirZ, "dirZ");
72          this.dirZ = dirZ;
73      }
74  
75      /**
76       * Construct a new DirectedPoint2d from a Point2d and a direction.
77       * @param point a point (with or without orientation)
78       * @param dirZ the counter-clockwise rotation around the point in radians
79       * @throws NullPointerException when <code>point</code> is <code>null</code>
80       * @throws ArithmeticException when <code>rotZ</code> is <code>NaN</code>
81       */
82      public DirectedPoint2d(final Point2d point, final double dirZ)
83      {
84          this(point.x, point.y, dirZ);
85      }
86  
87      /**
88       * Construct a new DirectedPoint2d from two coordinates and the coordinates of a point that the direction goes through.
89       * @param x the x coordinate of the of the new DirectedPoint
90       * @param y the y coordinate of the of the new DirectedPoint
91       * @param throughX the x-coordinate of a point that the direction goes through
92       * @param throughY the y-coordinate of a point that the direction goes through
93       * @throws ArithmeticException when <code>throughX</code>, or <code>throughY</code> is <code>null</code>
94       * @throws IllegalArgumentException when <code>throughX == x</code> and <code>throughY == y</code>
95       */
96      public DirectedPoint2d(final double x, final double y, final double throughX, final double throughY)
97      {
98          this(x, y, buildDirection(throughX - x, throughY - y));
99      }
100 
101     /**
102      * Build the direction.
103      * @param dX x difference
104      * @param dY y difference
105      * @return the computed value of dirZ
106      * @throws IllegalArgumentException when <code>dX == 0.0</code> and <code>dY == 0.0</code>
107      */
108     private static double buildDirection(final double dX, final double dY)
109     {
110         Throw.when(0 == dX && 0 == dY, IllegalArgumentException.class, "Through point may not be equal to point");
111         return Math.atan2(dY, dX);
112     }
113 
114     /**
115      * Construct a new DirectedPoint2d from a Point2d and a point that the direction goes through.
116      * @param point the point
117      * @param throughPoint the point that the direction goes through
118      * @throws NullPointerException when <code>point</code> is <code>null</code>, or <code>throughPoint</code> ==
119      *             <code>null</code>
120      * @throws IllegalArgumentException when <code>throughX == point.x</code> and <code>throughY ==
121      *             point.y</code>
122      */
123     public DirectedPoint2d(final Point2d point, final Point2d throughPoint)
124     {
125         this(Throw.whenNull(point, "point").x, point.y, Throw.whenNull(throughPoint, "throughPoint").x, throughPoint.y);
126     }
127 
128     /**
129      * Construct a new DirectedPoint2d from a Point2d and the coordinates of a point that the direction goes through.
130      * @param point the point
131      * @param throughX the x coordinate of a point that the direction goes through
132      * @param throughY the y coordinate of a point that the direction goes through
133      * @throws NullPointerException when <code>point</code> is <code>null</code>
134      * @throws ArithmeticException when <code>throughX</code>, or <code>throughY</code> is <code>NaN</code>
135      * @throws IllegalArgumentException when <code>throughX == point.x</code> and <code>throughY ==
136      *             point.y</code>
137      */
138     public DirectedPoint2d(final Point2d point, final double throughX, final double throughY)
139     {
140         this(Throw.whenNull(point, "point").x, point.y, throughX, throughY);
141     }
142 
143     @Override
144     public DirectedPoint2d translate(final double dX, final double dY)
145     {
146         return new DirectedPoint2d(this.x + dX, this.y + dY, this.dirZ);
147     }
148 
149     @Override
150     public DirectedPoint3d translate(final double dX, final double dY, final double z)
151             throws ArithmeticException, IllegalArgumentException
152     {
153         return new DirectedPoint3d(this.x + dX, this.y + dY, z, 0, this.dirZ);
154     }
155 
156     @Override
157     public DirectedPoint2d scale(final double factor) throws IllegalArgumentException
158     {
159         Throw.whenNaN(factor, "factor");
160         return new DirectedPoint2d(this.x * factor, this.y * factor, this.dirZ);
161     }
162 
163     @Override
164     public DirectedPoint2d neg()
165     {
166         return new DirectedPoint2d(-this.x, -this.y, AngleUtil.normalizeAroundZero(this.dirZ + Math.PI));
167     }
168 
169     @Override
170     public DirectedPoint2d abs()
171     {
172         return new DirectedPoint2d(Math.abs(this.x), Math.abs(this.y), this.dirZ);
173     }
174 
175     @Override
176     public DirectedPoint2d normalize() throws IllegalArgumentException
177     {
178         double length = Math.sqrt(this.x * this.x + this.y * this.y);
179         Throw.when(length == 0.0, IllegalArgumentException.class, "cannot normalize (0.0, 0.0)");
180         return this.scale(1.0 / length);
181     }
182 
183     /**
184      * Interpolate towards another DirectedPoint2d with a fraction. It is allowed for fraction to be less than zero or larger
185      * than 1. In that case the interpolation turns into an extrapolation. DirZ is interpolated using the
186      * AngleUtil.interpolateShortest method.
187      * @param otherPoint the other point
188      * @param fraction the factor for interpolation towards the other point. When &lt;code&gt;fraction&lt;/code&gt; is between 0
189      *            and 1, it is an interpolation, otherwise an extrapolation. If <code>fraction</code> is 0; <code>this</code>
190      *            Point is returned; if <code>fraction</code> is 1, the <code>otherPoint</code> is returned
191      * @return a new OrientedPoint2d at the requested fraction
192      * @throws NullPointerException when <code>otherPoint</code> is <code>null</code>
193      * @throws ArithmeticException when <code>fraction</code> is <code>NaN</code>
194      */
195     public DirectedPoint2d interpolate(final DirectedPoint2d otherPoint, final double fraction)
196     {
197         Throw.whenNull(otherPoint, "otherPoint");
198         Throw.whenNaN(fraction, "fraction");
199         if (0.0 == fraction)
200         {
201             return this;
202         }
203         if (1.0 == fraction)
204         {
205             return otherPoint;
206         }
207         return new DirectedPoint2d((1.0 - fraction) * this.x + fraction * otherPoint.x,
208                 (1.0 - fraction) * this.y + fraction * otherPoint.y,
209                 AngleUtil.interpolateShortest(this.dirZ, otherPoint.dirZ, fraction));
210     }
211 
212     /**
213      * Return a new DirectedPoint2d with an in-place rotation around the z-axis by the provided rotateZ. The resulting rotation
214      * is normalized between -&pi; and &pi;.
215      * @param rotateZ the rotation around the z-axis
216      * @return a new point with the same coordinates and applied rotation
217      * @throws ArithmeticException when <code>rotateZ</code> is <code>NaN</code>
218      */
219     public DirectedPoint2d rotate(final double rotateZ)
220     {
221         Throw.whenNaN(rotateZ, "rotateZ");
222         return new DirectedPoint2d(this.x, this.y, AngleUtil.normalizeAroundZero(this.dirZ + rotateZ));
223     }
224 
225     @Override
226     public double getDirZ()
227     {
228         return this.dirZ;
229     }
230 
231     @Override
232     public Iterator<Point2d> iterator()
233     {
234         return Arrays.stream(new Point2d[] {this}).iterator();
235     }
236 
237     @Override
238     public String toString()
239     {
240         return toString("%f", false);
241     }
242 
243     @Override
244     public String toString(final String doubleFormat, final boolean doNotIncludeClassName)
245     {
246         String format =
247                 String.format("%1$s[x=%2$s, y=%2$s, dirZ=%2$s]", doNotIncludeClassName ? "" : "DirectedPoint2d ", doubleFormat);
248         return String.format(Locale.US, format, this.x, this.y, this.dirZ);
249     }
250 
251     /**
252      * Compare this Directed with another Directed with specified tolerances in the coordinates and the angles.
253      * @param other the Directed to compare to
254      * @param epsilonCoordinate the upper bound of difference for one of the coordinates; use Double.POSITIVE_INFINITY if you do
255      *            not want to check the coordinates
256      * @param epsilonDirection the upper bound of difference for the direction(s); use Double.POSITIVE_INFINITY if you do not
257      *            want to check the angles
258      * @return boolean;<code>true</code> if <code>x</code> and <code>y</code> are less than <code>epsilonCoordinate</code>
259      *         apart, and <code>rotZ</code> is less than <code>epsilonDirection</code> apart, otherwise <code>false</code>
260      * @throws NullPointerException when <code>other</code> is <code>null</code>
261      * @throws ArithmeticException when <code>epsilonCoordinate</code> or <code>epsilonDirection</code> is <code>NaN</code>
262      * @throws IllegalArgumentException <code>epsilonCoordinate</code> or <code>epsilonDirection</code> is <code>negative</code>
263      */
264     public boolean epsilonEquals(final DirectedPoint2d other, final double epsilonCoordinate, final double epsilonDirection)
265             throws NullPointerException, IllegalArgumentException
266     {
267         Throw.whenNull(other, "other");
268         Throw.whenNaN(epsilonCoordinate, "epsilonCoordinate");
269         Throw.whenNaN(epsilonDirection, "epsilonDirection");
270         Throw.when(epsilonCoordinate < 0 || epsilonDirection < 0, IllegalArgumentException.class,
271                 "epsilonCoordinate and epsilonRotation may not be negative");
272         if (Math.abs(this.x - other.x) > epsilonCoordinate)
273         {
274             return false;
275         }
276         if (Math.abs(this.y - other.y) > epsilonCoordinate)
277         {
278             return false;
279         }
280         if (Math.abs(AngleUtil.normalizeAroundZero(this.dirZ - other.dirZ)) > epsilonDirection)
281         {
282             return false;
283         }
284         return true;
285     }
286 
287     @Override
288     public int hashCode()
289     {
290         final int prime = 31;
291         int result = super.hashCode();
292         result = prime * result + Objects.hash(this.dirZ);
293         return result;
294     }
295 
296     @Override
297     @SuppressWarnings("checkstyle:needbraces")
298     public boolean equals(final Object obj)
299     {
300         if (this == obj)
301             return true;
302         if (!super.equals(obj))
303             return false;
304         if (getClass() != obj.getClass())
305             return false;
306         DirectedPoint2d other = (DirectedPoint2d) obj;
307         return Double.doubleToLongBits(this.dirZ) == Double.doubleToLongBits(other.dirZ);
308     }
309 
310 }