Mercurial > dive4elements > river
changeset 1797:5eec623db50a
Polygon2D: moved 2D vector operation to separate class.
flys-artifacts/trunk@3120 c6561f87-3c4e-4783-a992-168aeb5c3f6f
| author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
|---|---|
| date | Mon, 31 Oct 2011 10:03:32 +0000 |
| parents | ae6ace900c07 |
| children | 552888e9c64a |
| files | flys-artifacts/ChangeLog flys-artifacts/src/main/java/de/intevation/flys/artifacts/geom/Polygon2D.java flys-artifacts/src/main/java/de/intevation/flys/artifacts/geom/VectorUtils.java |
| diffstat | 3 files changed, 93 insertions(+), 60 deletions(-) [+] |
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--- a/flys-artifacts/ChangeLog Mon Oct 31 10:01:08 2011 +0000 +++ b/flys-artifacts/ChangeLog Mon Oct 31 10:03:32 2011 +0000 @@ -1,3 +1,11 @@ +2011-10-31 Sascha L. Teichmann <sascha.teichmann@intevation.de> + + * src/main/java/de/intevation/flys/artifacts/geom/VectorUtils.java: + New. Vector operations on Point2D. + + * src/main/java/de/intevation/flys/artifacts/geom/Polygon2D.java: + Moved vector operations to VectorUtils. + 2011-10-31 Sascha L. Teichmann <sascha.teichmann@intevation.de> * src/main/java/de/intevation/flys/artifacts/model/WKmsFactory.java:
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/geom/Polygon2D.java Mon Oct 31 10:01:08 2011 +0000 +++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/geom/Polygon2D.java Mon Oct 31 10:03:32 2011 +0000 @@ -16,8 +16,6 @@ public class Polygon2D implements Serializable { - public static final double EPSILON = 1e-4; - private static final double X(Point2D p) { return p.getX(); } @@ -52,11 +50,6 @@ points = new ArrayList<Point2D>(); } - public static boolean epsilonEquals(Point2D a, Point2D b) { - return Math.abs(X(a)-X(b)) < EPSILON - && Math.abs(Y(a)-Y(b)) < EPSILON; - } - public void add(double x, double y) { points.add(new Point2D.Double(x, y)); } @@ -67,7 +60,7 @@ points.add(p); return true; case 1: - if (epsilonEquals(points.get(0), p)) { + if (VectorUtils.epsilonEquals(points.get(0), p)) { return false; } points.add(p); @@ -75,11 +68,11 @@ default: int L = points.size()-1; Point2D last = points.get(L); - if (epsilonEquals(last, p)) { + if (VectorUtils.epsilonEquals(last, p)) { return false; } Point2D before = points.get(L-1); - if (collinear(before, last, p)) { + if (VectorUtils.collinear(before, last, p)) { points.set(L, p); } else { @@ -95,56 +88,6 @@ } } - private static final double L1(Point2D a, Point2D b) { - return Math.abs(X(a)-X(b)) + Math.abs(Y(a)-Y(b)); - } - - public static boolean collinear(Point2D a, Point2D b, Point2D c) { - double dab = L1(a, b); - double dac = L1(a, c); - double dbc = L1(b, c); - - Point2D p1, p2, p3; - - if (dab > dac) { - if (dab > dbc) { - p1 = a; - p2 = b; - p3 = c; - } - else { // dbc >= dab - p1 = b; - p2 = c; - p3 = a; - } - } - else { // dac >= dab - if (dac > dbc) { - p1 = a; - p2 = c; - p3 = b; - } - else { // dbc >= dac - p1 = b; - p2 = c; - p3 = a; - } - } - - // TODO: Continue here. - - - return true; - } - - public static Point2D sub(Point2D a, Point2D b) { - return new Point2D.Double(X(a)-X(b), Y(a)-Y(b)); - } - - public static Point2D scale(Point2D a, double s) { - return new Point2D.Double(s*X(a), s*Y(a)); - } - public double area() { double area = 0d;
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/geom/VectorUtils.java Mon Oct 31 10:03:32 2011 +0000 @@ -0,0 +1,82 @@ +package de.intevation.flys.geom; + +import java.awt.geom.Point2D; + +public final class VectorUtils +{ + public static final double EPSILON = 1e-4; + + private VectorUtils() { + } + + private static final double X(Point2D p) { + return p.getX(); + } + + private static final double Y(Point2D p) { + return p.getY(); + } + + public static final Point2D sub(Point2D a, Point2D b) { + return new Point2D.Double(X(a)-X(b), Y(a)-Y(b)); + } + + public static final double dot(Point2D a, Point2D b) { + return X(a)*X(b) + Y(a)*Y(b); + } + + public static final Point2D add(Point2D a, Point2D b) { + return new Point2D.Double(X(a)+X(b), Y(a)+Y(b)); + } + + public static final Point2D negate(Point2D a) { + return new Point2D.Double(-X(a), -Y(a)); + } + + public static final Point2D ortho(Point2D a) { + return new Point2D.Double(-Y(a), X(a)); + } + + public static final Point2D scale(Point2D a, double s) { + return new Point2D.Double(s*X(a), s*Y(a)); + } + + public static final double lengthSq(Point2D a) { + double x = X(a); + double y = Y(a); + return x*x + y*y; + } + + public static final double length(Point2D a) { + return Math.sqrt(lengthSq(a)); + } + + public static final Point2D normalize(Point2D a) { + double length = length(a); + return length != 0d + ? scale(a, 1d/length) + : new Point2D.Double(X(a), Y(a)); + } + + public static final double L1(Point2D a, Point2D b) { + return Math.abs(X(a)-X(b)) + Math.abs(Y(a)-Y(b)); + } + + public static final boolean collinear(Point2D a, Point2D b, Point2D c) { + double x1 = X(a); + double y1 = Y(a); + double x2 = X(b); + double y2 = Y(b); + double x3 = X(c); + double y3 = Y(c); + + return Math.abs((x2-x1)*(y3-y1)-(y2-y1)*(x3-x1)) < EPSILON; + } + + public static boolean epsilonEquals(Point2D a, Point2D b) { + return Math.abs(X(a)-X(b)) < EPSILON + && Math.abs(Y(a)-Y(b)) < EPSILON; + } + +} +// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :