Mercurial > dive4elements > river
comparison flys-artifacts/src/main/java/org/dive4elements/river/artifacts/math/Utils.java @ 5831:bd047b71ab37
Repaired internal references
| author | Sascha L. Teichmann <teichmann@intevation.de> |
|---|---|
| date | Thu, 25 Apr 2013 12:06:39 +0200 |
| parents | flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/Utils.java@b195fede1c3b |
| children |
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| 5830:160f53ee0870 | 5831:bd047b71ab37 |
|---|---|
| 1 package org.dive4elements.river.artifacts.math; | |
| 2 | |
| 3 | |
| 4 public final class Utils { | |
| 5 | |
| 6 public static final double EPSILON = 1e-3; | |
| 7 | |
| 8 private Utils() { | |
| 9 } | |
| 10 | |
| 11 public static final boolean epsilonEquals(double a, double b) { | |
| 12 return epsilonEquals(a, b, EPSILON); | |
| 13 } | |
| 14 | |
| 15 public static final boolean epsilonEquals(double a, double b, double eps) { | |
| 16 return Math.abs(a - b) < eps; | |
| 17 } | |
| 18 | |
| 19 public static int relativeCCW( | |
| 20 double x1, double y1, | |
| 21 double x2, double y2, | |
| 22 double px, double py | |
| 23 ) { | |
| 24 if ((epsilonEquals(x1, x2) && epsilonEquals(y1, y2)) | |
| 25 || ((epsilonEquals(x1, px) && epsilonEquals(y1, py)))) { | |
| 26 return 0; // Coincident points. | |
| 27 } | |
| 28 // Translate to the origin. | |
| 29 x2 -= x1; | |
| 30 y2 -= y1; | |
| 31 px -= x1; | |
| 32 py -= y1; | |
| 33 double slope2 = y2 / x2; | |
| 34 double slopep = py / px; | |
| 35 if (epsilonEquals(slope2, slopep) | |
| 36 || (epsilonEquals(x2, 0.0) && epsilonEquals(px, 0.0))) { | |
| 37 return y2 > EPSILON // Colinear. | |
| 38 ? (py < -EPSILON ? -1 : py > y2 ? 1 : 0) | |
| 39 : (py > -EPSILON ? -1 : py < y2 ? 1 : 0); | |
| 40 } | |
| 41 if (x2 >= EPSILON && slope2 >= EPSILON) { | |
| 42 return px >= EPSILON // Quadrant 1. | |
| 43 ? (slope2 > slopep ? 1 : -1) | |
| 44 : (slope2 < slopep ? 1 : -1); | |
| 45 } | |
| 46 | |
| 47 if (y2 > EPSILON) { | |
| 48 return px < -EPSILON // Quadrant 2. | |
| 49 ? (slope2 > slopep ? 1 : -1) | |
| 50 : (slope2 < slopep ? 1 : -1); | |
| 51 } | |
| 52 if (slope2 >= EPSILON) { | |
| 53 return px >= EPSILON // Quadrant 3. | |
| 54 ? (slope2 < slopep ? 1 : -1) | |
| 55 : (slope2 > slopep ? 1 : -1); | |
| 56 } | |
| 57 return px < -EPSILON // Quadrant 4. | |
| 58 ? (slope2 < slopep ? 1 : -1) | |
| 59 : (slope2 > slopep ? 1 : -1); | |
| 60 } | |
| 61 } |