--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gnv-artifacts/src/main/java/de/intevation/gnv/raster/IsoProducer.java	Fri Sep 28 12:14:00 2012 +0200
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2010 by Intevation GmbH
+ *
+ * This program is free software under the LGPL (>=v2.1)
+ * Read the file LGPL.txt coming with the software for details
+ * or visit http://www.gnu.org/licenses/ if it does not exist.
+ */
+
+package de.intevation.gnv.raster;
+
+import de.intevation.gnv.math.IJKey;
+
+import de.intevation.gnv.raster.Vectorizer.Edge;
+
+import gnu.trove.TIntHashSet;
+import gnu.trove.TIntObjectHashMap;
+import gnu.trove.TObjectProcedure;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+
+/**
+ * Vectorizer backend to generate iso lines as line strings
+ * and custom labels on the chart.
+ *
+ * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
+ */
+public class IsoProducer
+extends      AbstractProducer
+{
+    /**
+     * Iso lines separate two neighbors. This interface decouples
+     * the generation of a suitable label for these to neighbors.
+     */
+    public interface AttributeGenerator {
+
+        /**
+         * Generate attribute show as label for two given neighbors.
+         * @param neighbor1 The first neighbor.
+         * @param neighbor2 The second neighbor.
+         * @return The label attribute.
+         */
+        Object generateAttribute(int neighbor1, int neighbor2);
+
+    } // interface AttributeGenerator
+
+    /**
+     * Internal map of open edge to neighbor attributes.
+     */
+    protected HashMap<Edge, Integer>            open;
+    /**
+     * Internal map to associate neighbors with open edges.
+     */
+    protected HashMap<IJKey, TIntObjectHashMap> commonOpen;
+    /**
+     * Internal map to associate neighbors with complete rings.
+     */
+    protected HashMap<IJKey, ArrayList<Edge>>   complete;
+
+    /**
+     * Width of the index space.
+     */
+    protected int    width;
+    /**
+     * Height of the index space.
+     */
+    protected int    height;
+
+    /**
+     * Constructor with a given world bounding box.
+     * @param minX Min x coord of the world.
+     * @param minY Min y coord of the world.
+     * @param maxX Max x coord of the world.
+     * @param maxY Max y coord of the world.
+     */
+    public IsoProducer(
+        double minX, double minY,
+        double maxX, double maxY
+    ) {
+        super(minX, minY, maxX, maxY);
+
+        open       = new HashMap<Edge, Integer>();
+        commonOpen = new HashMap<IJKey, TIntObjectHashMap>();
+        complete   = new HashMap<IJKey, ArrayList<Edge>>();
+    }
+
+    public void handleRings(
+        List<Edge> rings,
+        int        value,
+        int        width,
+        int        height
+    ) {
+        if (value == -1) {
+            return;
+        }
+        this.width  = width;
+        this.height = height;
+
+        Integer v = Integer.valueOf(value);
+
+        for (Edge head: rings) {
+            Edge current = head;
+            do {
+                Integer neighbor = open.remove(current);
+
+                if (neighbor != null) {
+                    IJKey pair = new IJKey(value, neighbor.intValue());
+                    pair.sort();
+
+                    TIntObjectHashMap co = commonOpen.get(pair);
+
+                    if (co == null) {
+                        commonOpen.put(pair, co = new TIntObjectHashMap());
+                    }
+
+                    Edge edge = new Edge(current);
+
+                    Edge otherA = (Edge)co.remove(edge.a);
+                    if (otherA != null) {
+                        otherA.chain(edge, edge.a);
+                    }
+
+                    Edge otherB = (Edge)co.remove(edge.b);
+                    if (otherB != null) {
+                        otherB.chain(edge, edge.b);
+                    }
+
+                    if (edge.isComplete()) {
+                        ArrayList list = complete.get(pair);
+                        if (list == null) {
+                            complete.put(pair, list = new ArrayList());
+                        }
+                        list.add(Vectorizer.simplify(edge, width));
+                    }
+                    else {
+                        if (otherA == null) {
+                            co.put(edge.a, edge);
+                        }
+                        if (otherB == null) {
+                            co.put(edge.b, edge);
+                        }
+                    }
+                }
+                else {
+                    Edge edge = new Edge(current.b, current.a);
+                    open.put(edge, v);
+                }
+
+                current = current.next;
+            }
+            while (current != head);
+        } // for all rings
+
+    } // handleRings
+
+    /**
+     * Join the pairs of neighbors i,j to have a distinct set.
+     * @return The distinct pairs of neighbors.
+     */
+    protected HashSet<IJKey> joinPairs() {
+        HashSet<IJKey> pairs = new HashSet<IJKey>();
+        pairs.addAll(complete  .keySet());
+        pairs.addAll(commonOpen.keySet());
+        return pairs;
+    }
+
+    /**
+     * Filter out the head list from the open edge lists.
+     * @param map Map of end and head lists.
+     * @return list of only head lists.
+     */
+    protected static ArrayList<Edge> headList(TIntObjectHashMap map) {
+        final ArrayList<Edge> headList = new ArrayList<Edge>();
+        map.forEachValue(new TObjectProcedure() {
+            TIntHashSet headSet = new TIntHashSet();
+            public boolean execute(Object value) {
+                Edge head = ((Edge)value).head();
+                if (headSet.add(head.a)) {
+                    headList.add(head);
+                }
+                return true;
+            }
+        });
+        return headList;
+    }
+
+    /**
+     * Reset internal data structures to save some memory.
+     */
+    public void clear() {
+        open.clear();
+        complete.clear();
+        commonOpen.clear();
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :