Mercurial > dive4elements > gnv-client
comparison gnv-artifacts/src/main/java/de/intevation/gnv/math/LinearMetrics.java @ 1119:7c4f81f74c47
merged gnv-artifacts
| author | Thomas Arendsen Hein <thomas@intevation.de> |
|---|---|
| date | Fri, 28 Sep 2012 12:14:00 +0200 |
| parents | f953c9a559d8 |
| children |
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| 1027:fca4b5eb8d2f | 1119:7c4f81f74c47 |
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| 1 /* | |
| 2 * Copyright (c) 2010 by Intevation GmbH | |
| 3 * | |
| 4 * This program is free software under the LGPL (>=v2.1) | |
| 5 * Read the file LGPL.txt coming with the software for details | |
| 6 * or visit http://www.gnu.org/licenses/ if it does not exist. | |
| 7 */ | |
| 8 | |
| 9 package de.intevation.gnv.math; | |
| 10 | |
| 11 import com.vividsolutions.jts.geom.Coordinate; | |
| 12 | |
| 13 /** | |
| 14 * Implements {@link de.intevation.gnv.math.Metrics} | |
| 15 * for linear interpolations and distance measurements. | |
| 16 * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a> | |
| 17 */ | |
| 18 public final class LinearMetrics | |
| 19 implements Metrics | |
| 20 { | |
| 21 /** | |
| 22 * Instance to prevent needless creations of instances. | |
| 23 */ | |
| 24 public static final Metrics INSTANCE = | |
| 25 new LinearMetrics(); | |
| 26 | |
| 27 /** | |
| 28 * Implements the corresponding linear interpolator. | |
| 29 */ | |
| 30 public static final class LinearInterpolator | |
| 31 implements Interpolator | |
| 32 { | |
| 33 private double mx; | |
| 34 private double bx; | |
| 35 private double my; | |
| 36 private double by; | |
| 37 | |
| 38 /** | |
| 39 * Constructor to create a linear interpolator between two | |
| 40 * given points. | |
| 41 * @param p1 The first point. | |
| 42 * @param p2 The second point. | |
| 43 */ | |
| 44 public LinearInterpolator(Coordinate p1, Coordinate p2) { | |
| 45 | |
| 46 /* | |
| 47 I) p1.x = 0*m + bx | |
| 48 II) p2.x = 1*m + bx | |
| 49 | |
| 50 bx = p1.x | |
| 51 | |
| 52 p2.x = m + p1.x | |
| 53 | |
| 54 mx = p2.x - p1.x | |
| 55 */ | |
| 56 | |
| 57 bx = p1.x; | |
| 58 mx = p2.x - bx; | |
| 59 | |
| 60 by = p1.y; | |
| 61 my = p2.y - by; | |
| 62 } | |
| 63 | |
| 64 public void interpolate(double t, Coordinate v) { | |
| 65 v.x = t*mx + bx; | |
| 66 v.y = t*my + by; | |
| 67 } | |
| 68 } // class LinearInterpolator | |
| 69 | |
| 70 private LinearMetrics() { | |
| 71 } | |
| 72 | |
| 73 public double distance(Coordinate p1, Coordinate p2) { | |
| 74 return p1.distance(p2); | |
| 75 } | |
| 76 | |
| 77 public Interpolator getInterpolator(Coordinate p1, Coordinate p2) { | |
| 78 return new LinearInterpolator(p1, p2); | |
| 79 } | |
| 80 } | |
| 81 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 : |