Application: gvSIG desktop » gvSIG legends: base legends

package org.gvsig.legend.heatmap.lib.impl;

import java.awt.Color;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;

import java.util.Map;

import org.cresques.cts.ICoordTrans;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.dal.feature.Feature;

import org.gvsig.fmap.dal.feature.FeatureQuery;

import org.gvsig.fmap.dal.feature.FeatureSelection;

import org.gvsig.fmap.dal.feature.FeatureSet;

import org.gvsig.fmap.dal.feature.FeatureStore;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.primitive.Point;

import org.gvsig.fmap.mapcontext.MapContextException;

import org.gvsig.fmap.mapcontext.ViewPort;

import org.gvsig.fmap.mapcontext.rendering.legend.LegendException;

import org.gvsig.fmap.mapcontext.rendering.symbols.ISymbol;

import org.gvsig.legend.heatmap.lib.api.HeatmapLegend;

import org.gvsig.symbology.fmap.mapcontext.rendering.legend.impl.AbstractVectorialLegend;

import org.gvsig.symbology.fmap.mapcontext.rendering.legend.impl.DefaultFeatureDrawnNotification;

import org.gvsig.symbology.fmap.mapcontext.rendering.symbol.text.impl.SimpleTextSymbol;

import org.gvsig.tools.exception.BaseException;

import org.gvsig.tools.task.Cancellable;

import org.gvsig.tools.visitor.VisitCanceledException;

import org.gvsig.tools.visitor.Visitor;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class DefaultHeatmapLegend extends AbstractVectorialLegend implements HeatmapLegend {

    protected static final Logger LOG = LoggerFactory.getLogger(DefaultHeatmapLegend.class);

    private class DensityAlgorithm {

        private double[][] grid;

        private double[][] kernel;

        private int distance;

        private int height;

        private int with;

        private double maxValue;

        private double minValue;

        public DensityAlgorithm(int distance) {

            this.setDistance(distance);

        }

        public void setDistance(int distance) {

            this.distance = distance;

            this.kernel = new double[2 * this.distance + 1][2 * this.distance + 1];

            for( int y = -this.distance; y < this.distance + 1; y++ ) {

                for( int x = -this.distance; x < this.distance + 1; x++ ) {

                    final double dDist = Math.sqrt(x * x + y * y);

                    if( dDist < this.distance ) {

                        this.kernel[x + this.distance][y + this.distance] = Math.pow(1 - (dDist * dDist) / (this.distance * this.distance), 2);

                    } else {

                        this.kernel[x + this.distance][y + this.distance] = 0;

                    }

                }

            }

        }

        public int getDistance() {

            return this.distance;

        }

        public void init(int with, int height) {

            this.with = with;

            this.height = height;

            this.grid = new double[with][height];

            this.maxValue = 0;

            this.minValue = 0;

        }

        public void add(int px, int py) {

            add(px, py, 1);

        }

        public void add(int px, int py, double value) {

            for( int y = -this.distance; y < this.distance + 1; y++ ) {

                for( int x = -this.distance; x < this.distance + 1; x++ ) {

                    if( this.kernel[x + this.distance][y + this.distance] != 0 ) {

                        addValue(px + x, py + y, value * this.kernel[x + this.distance][y + this.distance]);

                    }

                }

            }

        }

        private void addValue(int px, int py, double value) {

            if( px<0 || py<0 || px>=with || py>=height ) {

                return;

            }

            value += this.grid[px][py];

            this.grid[px][py] = value;

            if( value > this.maxValue ) {

                this.maxValue = value;

            }

            if( value < this.minValue ) {

                this.minValue = value;

            }

        }

        public void draw(BufferedImage img, Color[] colorTable, Cancellable cancel) {

            try {

                int maxColors = colorTable.length;

                for( int x = 0; x < with; x++ ) {

                    for( int y = 0; y < height; y++ ) {

                        if( cancel.isCanceled() ) {

                            return;

                        }

                        double value = this.grid[x][y];

                        if( value > 0 ) {

                            int icolor = (int) (value * maxColors / maxValue);

                            icolor = icolor<0? 0: icolor>=maxColors?maxColors-1:icolor;

                            Color c = colorTable[icolor];

                            img.setRGB(x, y, c.getRGB());

                        }

                    }

                }

            } catch (Exception ex) {

                LOG.warn("Problems drawing heatmap", ex);

            }

        }

    }

    private final ISymbol defaultSymbol;

    private final DensityAlgorithm algorithm;

//    private int distance; // Pixels

    private Color[] colorTable;

    private int opacity;

    public DefaultHeatmapLegend() {

        this.defaultSymbol = new SimpleTextSymbol();

        this.algorithm = new DensityAlgorithm(30);

        this.opacity = 100;

        this.colorTable = createColorTable(255, Color.RED, Color.WHITE);

    }

    @Override

    protected String[] getRequiredFeatureAttributeNames(FeatureStore featureStore) throws DataException {

        return new String[]{

            featureStore.getDefaultFeatureType().getDefaultGeometryAttributeName()};

    }

    @Override

    public ISymbol getDefaultSymbol() {

        return this.defaultSymbol;

    }

    @Override

    public void setDefaultSymbol(ISymbol is) {

    }

    @Override

    public ISymbol getSymbolByFeature(Feature ftr) throws MapContextException {

        return this.defaultSymbol;

    }

    @Override

    public int getShapeType() {

        return Geometry.TYPES.GEOMETRY;

    }

    @Override

    public void setShapeType(int i) {

    }

    @Override

    public boolean isUseDefaultSymbol() {

        return true;

    }

    @Override

    public void useDefaultSymbol(boolean bln) {

    }

    @Override

    public boolean isSuitableForShapeType(int shapeType) {

        return true;

    }

    @Override

    protected void draw(BufferedImage image, Graphics2D g, ViewPort viewPort, Cancellable cancel, double scale, Map queryParameters, ICoordTrans coordTrans, FeatureStore featureStore, FeatureQuery featureQuery, double dpi) throws LegendException {

        this.algorithm.init(image.getWidth(), image.getHeight());

        super.draw(image, g, viewPort, cancel, scale, queryParameters, coordTrans, featureStore, featureQuery, dpi);

        if( !cancel.isCanceled() ) {

            this.algorithm.draw(image, this.colorTable, cancel);

        }

    }

    @Override

    protected void drawFeatures(

        BufferedImage image,

        Graphics2D g,

        final ViewPort viewPort,

        final Cancellable cancel,

        final ICoordTrans coordTrans,

        double dpi,

        DefaultFeatureDrawnNotification drawnNotification,

        FeatureSet featureSet,

        FeatureSelection selection

    ) throws BaseException {

        featureSet.accept(new Visitor() {

            @Override

            public void visit(Object o) throws VisitCanceledException, BaseException {

                if( cancel.isCanceled() ) {

                    throw new VisitCanceledException();

                }

                Feature feature = (Feature) o;

                Geometry geom = feature.getDefaultGeometry();

                if( geom != null ) {

                    Point pointGeo = geom.centroid();

                    if( coordTrans != null ) {

                        pointGeo.reProject(coordTrans);

                    }

                    Point pointPixels = (Point) pointGeo.cloneGeometry();

                    pointPixels.transform(viewPort.getAffineTransform());

                    algorithm.add((int) pointPixels.getX(), (int) pointPixels.getY());

                }

            }

        });

    }

    private Color[] createColorTable(int elements, Color first, Color last) {

        Color[] table = new Color[elements];

        for( int i = 0; i < elements; i++ ) {

            table[i] = new Color(i, 0, 0, i); //, this.opacity);

//            double p = (i * 255.0 ) / elements;

//            int r = (int) (first.getRed() * p + last.getRed() * (1 - p));

//            int g = (int) (first.getGreen()* p + last.getGreen() * (1 - p));

//            int b = (int) (first.getBlue()* p + last.getBlue()* (1 - p));

//            

//            r = r>255?255:r<0?0:r;

//            g = g>255?255:g<0?0:g;

//            b = b>255?255:b<0?0:0;

//            table[i] = new Color(r,g,b, this.opacity);

        }

        return table;

    }

    /**

     * @return the distance

     */

    @Override

    public int getDistance() {

        return this.algorithm.getDistance();

    }

    /**

     * @param distance the distance to set

     */

    @Override

    public void setDistance(int distance) {

        this.algorithm.setDistance(distance);

    }

}