Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/Utils.java @ 4357:11cf29eb002c
FacetTypes: New type: exreme_wq_curve_base (for the Stuetz-Q-Poits).
author | Felix Wolfsteller <felix.wolfsteller@intevation.de> |
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date | Fri, 02 Nov 2012 11:58:11 +0100 |
parents | 5cc9453456a7 |
children | b195fede1c3b |
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package de.intevation.flys.artifacts.math; public final class Utils { public static final double EPSILON = 1e-3; private Utils() { } public static final boolean epsilonEquals(double a, double b) { return epsilonEquals(a, b, EPSILON); } public static final boolean epsilonEquals(double a, double b, double eps) { return Math.abs(a - b) < eps; } public static int relativeCCW( double x1, double y1, double x2, double y2, double px, double py ) { if ((epsilonEquals(x1, x2) && epsilonEquals(y1, y2)) || ((epsilonEquals(x1, px) && epsilonEquals(y1, py)))) { return 0; // Coincident points. } // Translate to the origin. x2 -= x1; y2 -= y1; px -= x1; py -= y1; double slope2 = y2 / x2; double slopep = py / px; if (epsilonEquals(slope2, slopep) || (epsilonEquals(x2, 0.0) && epsilonEquals(px, 0.0))) { return y2 > EPSILON // Colinear. ? (py < -EPSILON ? -1 : py > y2 ? 1 : 0) : (py > -EPSILON ? -1 : py < y2 ? 1 : 0); } if (x2 >= EPSILON && slope2 >= EPSILON) { return px >= EPSILON // Quadrant 1. ? (slope2 > slopep ? 1 : -1) : (slope2 < slopep ? 1 : -1); } if (y2 > EPSILON) { return px < -EPSILON // Quadrant 2. ? (slope2 > slopep ? 1 : -1) : (slope2 < slopep ? 1 : -1); } if (slope2 >= EPSILON) { return px >= EPSILON // Quadrant 3. ? (slope2 < slopep ? 1 : -1) : (slope2 > slopep ? 1 : -1); } return px < -EPSILON // Quadrant 4. ? (slope2 < slopep ? 1 : -1) : (slope2 > slopep ? 1 : -1); } }