sascha@436: package de.intevation.gnv.raster;
sascha@436: 
sascha@779: import de.intevation.gnv.jfreechart.CompactXYItems;
sascha@779: import de.intevation.gnv.jfreechart.PolygonDataset;
sascha@779: import de.intevation.gnv.jfreechart.PolygonSeries;
sascha@779: 
sascha@779: import de.intevation.gnv.raster.Vectorizer.Edge;
sascha@436: 
sascha@436: import gnu.trove.TDoubleArrayList;
sascha@436: 
sascha@779: import java.util.HashMap;
sascha@779: import java.util.List;
sascha@436: 
sascha@437: /**
sascha@801:  * Vectorizer backend to produce polygon datasets suitable to being
sascha@801:  * displayed with {@link de.intevation.gnv.jfreechart.PolygonPlot}.
sascha@803:  *
sascha@780:  * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
sascha@437:  */
sascha@436: public class PolygonDatasetProducer
sascha@465: extends      AbstractProducer
sascha@436: {
sascha@801:     /**
sascha@801:      * Maps value integers to series of polygons to group
sascha@801:      * them by value.
sascha@801:      */
sascha@436:     protected HashMap<Integer, PolygonSeries> polygonSeries;
sascha@436: 
sascha@801:     /**
sascha@801:      * Default constructor.
sascha@801:      */
sascha@436:     protected PolygonDatasetProducer() {
sascha@436:     }
sascha@436: 
sascha@801:     /**
sascha@801:      * Constructor to create a PolygonDatasetProducer with
sascha@801:      * a given world bound box.
sascha@801:      * @param minX Min x coord of the world.
sascha@801:      * @param minY Min y coord of the world.
sascha@801:      * @param maxX Max x coord of the world.
sascha@801:      * @param maxY Max y coord of the world.
sascha@801:      */
sascha@436:     public PolygonDatasetProducer(
sascha@436:         double minX, double minY,
sascha@436:         double maxX, double maxY
sascha@436: 
sascha@436:     ) {
sascha@465:         super(minX, minY, maxX, maxY);
sascha@436:         polygonSeries = new HashMap<Integer, PolygonSeries>();
sascha@436:     }
sascha@436: 
sascha@436:     public void handleRings(
sascha@778:         List<Edge> rings,
sascha@778:         int        value,
sascha@436:         int        width,
sascha@436:         int        height
sascha@436:     ) {
sascha@436:         if (value == -1) {
sascha@436:             return;
sascha@436:         }
sascha@436: 
sascha@436:         Integer v = Integer.valueOf(value);
sascha@436: 
sascha@465:         PolygonSeries ps = polygonSeries.get(v);
sascha@436: 
sascha@436:         if (ps == null) {
sascha@436:             polygonSeries.put(v, ps = new PolygonSeries());
sascha@436:             ps.setAttribute("fill", v);
sascha@436:         }
sascha@436: 
sascha@436:         TDoubleArrayList vertices = new TDoubleArrayList();
sascha@436: 
sascha@436:         /* minX = 0*m1 + b1 <=> b1 = minX
sascha@436:          * maxX = (width-1)*m1 + b1
sascha@436:          * m1 = (maxX - minX)/(width-1)
sascha@436:          */
sascha@436: 
sascha@437:         double b1 = minX;
sascha@437:         double m1 = width != 1
sascha@437:            ? (maxX - minX)/(width-1)
sascha@437:            : 0d;
sascha@436: 
sascha@437:         double b2 = minY;
sascha@437:         double m2 = height != 1
sascha@437:            ? (maxY - minY)/(height-1)
sascha@437:            : 0d;
sascha@436: 
sascha@436:         for (Edge head: rings) {
sascha@436:             Edge current = head;
sascha@436:             do {
sascha@437:                 vertices.add(m1*(current.a % width) + b1);
sascha@437:                 vertices.add(m2*(current.a / width) + b2);
sascha@436:             }
sascha@437:             while ((current = current.next) != head);
sascha@436:             ps.addRing(new CompactXYItems(vertices.toNativeArray()));
sascha@521:             vertices.reset();
sascha@436:         }
sascha@436:     }
sascha@436: 
sascha@801:     /**
sascha@801:      * Creates a new PolygonDataset from the polygons build by this
sascha@801:      * backend.
sascha@801:      * @return the new PolygonDataset
sascha@801:      */
sascha@436:     public PolygonDataset getPolygonDataset() {
sascha@436:         return new PolygonDataset(polygonSeries.values());
sascha@436:     }
sascha@436: }
sascha@798: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :