Mercurial > dive4elements > gnv-client
comparison gnv-artifacts/src/main/java/de/intevation/gnv/math/LinearMetrics.java @ 875:5e9efdda6894
merged gnv-artifacts/1.0
| author | Thomas Arendsen Hein <thomas@intevation.de> |
|---|---|
| date | Fri, 28 Sep 2012 12:13:56 +0200 |
| parents | 05bf8534a35a |
| children | f953c9a559d8 |
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| 722:bb3ffe7d719e | 875:5e9efdda6894 |
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| 1 package de.intevation.gnv.math; | |
| 2 | |
| 3 import com.vividsolutions.jts.geom.Coordinate; | |
| 4 | |
| 5 /** | |
| 6 * Implements {@link de.intevation.gnv.math.Metrics} | |
| 7 * for linear interpolations and distance measurements. | |
| 8 * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a> | |
| 9 */ | |
| 10 public final class LinearMetrics | |
| 11 implements Metrics | |
| 12 { | |
| 13 /** | |
| 14 * Instance to prevent needless creations of instances. | |
| 15 */ | |
| 16 public static final Metrics INSTANCE = | |
| 17 new LinearMetrics(); | |
| 18 | |
| 19 /** | |
| 20 * Implements the corresponding linear interpolator. | |
| 21 */ | |
| 22 public static final class LinearInterpolator | |
| 23 implements Interpolator | |
| 24 { | |
| 25 private double mx; | |
| 26 private double bx; | |
| 27 private double my; | |
| 28 private double by; | |
| 29 | |
| 30 /** | |
| 31 * Constructor to create a linear interpolator between two | |
| 32 * given points. | |
| 33 * @param p1 The first point. | |
| 34 * @param p2 The second point. | |
| 35 */ | |
| 36 public LinearInterpolator(Coordinate p1, Coordinate p2) { | |
| 37 | |
| 38 /* | |
| 39 I) p1.x = 0*m + bx | |
| 40 II) p2.x = 1*m + bx | |
| 41 | |
| 42 bx = p1.x | |
| 43 | |
| 44 p2.x = m + p1.x | |
| 45 | |
| 46 mx = p2.x - p1.x | |
| 47 */ | |
| 48 | |
| 49 bx = p1.x; | |
| 50 mx = p2.x - bx; | |
| 51 | |
| 52 by = p1.y; | |
| 53 my = p2.y - by; | |
| 54 } | |
| 55 | |
| 56 public void interpolate(double t, Coordinate v) { | |
| 57 v.x = t*mx + bx; | |
| 58 v.y = t*my + by; | |
| 59 } | |
| 60 } // class LinearInterpolator | |
| 61 | |
| 62 private LinearMetrics() { | |
| 63 } | |
| 64 | |
| 65 public double distance(Coordinate p1, Coordinate p2) { | |
| 66 return p1.distance(p2); | |
| 67 } | |
| 68 | |
| 69 public Interpolator getInterpolator(Coordinate p1, Coordinate p2) { | |
| 70 return new LinearInterpolator(p1, p2); | |
| 71 } | |
| 72 } | |
| 73 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 : |