Mercurial > dive4elements > river

annotate flys-artifacts/src/main/java/de/intevation/flys/artifacts/geom/VectorUtils.java @ 1799:281b9430c720

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Polygon2D: More code to build polygons from curve. flys-artifacts/trunk@3123 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author Sascha L. Teichmann <sascha.teichmann@intevation.de>
date Mon, 31 Oct 2011 15:54:02 +0000
parents 5eec623db50a
children 6f83d9d434f2
rev   line source
1797
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
parents:
diff changeset
1 package de.intevation.flys.geom;
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
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2
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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3 import java.awt.geom.Point2D;
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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4
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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5 public final class VectorUtils
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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6 {
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7 public static final double EPSILON = 1e-4;
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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8
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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9 private VectorUtils() {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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10 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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11
1799
281b9430c720 Polygon2D: More code to build polygons from curve.
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12 public static final double X(Point2D p) {
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13 return p.getX();
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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14 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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15
1799
281b9430c720 Polygon2D: More code to build polygons from curve.
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parents: 1797
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16 public static final double Y(Point2D p) {
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17 return p.getY();
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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18 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
parents:
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19
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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20 public static final Point2D sub(Point2D a, Point2D b) {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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21 return new Point2D.Double(X(a)-X(b), Y(a)-Y(b));
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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22 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
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23
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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24 public static final double dot(Point2D a, Point2D b) {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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25 return X(a)*X(b) + Y(a)*Y(b);
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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26 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
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27
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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28 public static final Point2D add(Point2D a, Point2D b) {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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29 return new Point2D.Double(X(a)+X(b), Y(a)+Y(b));
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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30 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
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31
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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32 public static final Point2D negate(Point2D a) {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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33 return new Point2D.Double(-X(a), -Y(a));
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34 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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35
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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36 public static final Point2D ortho(Point2D a) {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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37 return new Point2D.Double(-Y(a), X(a));
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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38 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
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39
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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40 public static final Point2D scale(Point2D a, double s) {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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41 return new Point2D.Double(s*X(a), s*Y(a));
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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42 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
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43
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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44 public static final double lengthSq(Point2D a) {
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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45 double x = X(a);
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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46 double y = Y(a);
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47 return x*x + y*y;
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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48 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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49
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50 public static final double length(Point2D a) {
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51 return Math.sqrt(lengthSq(a));
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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52 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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53
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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54 public static final Point2D normalize(Point2D a) {
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55 double length = length(a);
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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56 return length != 0d
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57 ? scale(a, 1d/length)
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58 : new Point2D.Double(X(a), Y(a));
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59 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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60
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61 public static final double L1(Point2D a, Point2D b) {
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62 return Math.abs(X(a)-X(b)) + Math.abs(Y(a)-Y(b));
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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63 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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64
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65 public static final boolean collinear(Point2D a, Point2D b, Point2D c) {
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66 double x1 = X(a);
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67 double y1 = Y(a);
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68 double x2 = X(b);
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69 double y2 = Y(b);
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70 double x3 = X(c);
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71 double y3 = Y(c);
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72
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73 return Math.abs((x2-x1)*(y3-y1)-(y2-y1)*(x3-x1)) < EPSILON;
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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74 }
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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75
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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76 public static boolean epsilonEquals(Point2D a, Point2D b) {
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77 return Math.abs(X(a)-X(b)) < EPSILON
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78 && Math.abs(Y(a)-Y(b)) < EPSILON;
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79 }
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80
5eec623db50a Polygon2D: moved 2D vector operation to separate class.
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81 }
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82 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
http://dive4elements.wald.intevation.org