--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/backend/src/main/java/org/dive4elements/river/importer/XY.java	Mon Jan 20 14:04:20 2014 +0100
@@ -0,0 +1,106 @@
+/* Copyright (C) 2011, 2012, 2013 by Bundesanstalt für Gewässerkunde
+ * Software engineering by Intevation GmbH
+ *
+ * This file is Free Software under the GNU AGPL (>=v3)
+ * and comes with ABSOLUTELY NO WARRANTY! Check out the
+ * documentation coming with Dive4Elements River for details.
+ */
+
+package org.dive4elements.river.importer;
+
+
+/** Two doubles and an int index. */
+public class XY
+implements   Comparable<XY>
+{
+    public static final double X_EPSILON = 1e-4;
+
+    protected double x;
+    protected double y;
+    protected int    index;
+
+    public XY() {
+    }
+
+    public XY(XY other) {
+        this(other.x, other.y, other.index);
+    }
+
+    public XY(double x, double y, int index) {
+        this.x     = x;
+        this.y     = y;
+        this.index = index;
+    }
+
+    @Override
+    public int compareTo(XY other) {
+        if (x + X_EPSILON < other.x) return -1;
+        if (x > other.x + X_EPSILON) return +1;
+        if (index < other.index)     return -1;
+        if (index > other.index)     return +1;
+        return 0;
+    }
+
+    public double getX() {
+        return x;
+    }
+
+    public void setX(double x) {
+        this.x = x;
+    }
+
+    public double getY() {
+        return y;
+    }
+
+    public void setY(double y) {
+        this.y = y;
+    }
+
+    public int getIndex() {
+        return index;
+    }
+
+    public void setIndex(int index) {
+        this.index = index;
+    }
+
+    public double dot(double ox, double oy) {
+        return x*ox + y*oy;
+    }
+
+    public double dot(XY other) {
+        return dot(other.x, other.y);
+    }
+
+    public XY sub(XY other) {
+        x -= other.x;
+        y -= other.y;
+        return this;
+    }
+
+    public XY ortho() {
+        double z = x;
+        x = y;
+        y = -z;
+        return this;
+    }
+
+    public XY normalize() {
+        double len = dot(this);
+
+        if (len > 1e-6) {
+            len = 1d/Math.sqrt(len);
+            x *= len;
+            y *= len;
+        }
+
+        return this;
+    }
+
+    // x*nx + y*ny + d = 0 <=> d = -x*nx -y*ny
+    public double lineOffset(XY p) {
+         return -x*p.x -y*p.y;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :