001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.gui.layer.gpx;
003
004import static org.openstreetmap.josm.tools.I18n.marktr;
005import static org.openstreetmap.josm.tools.I18n.tr;
006
007import java.awt.AlphaComposite;
008import java.awt.BasicStroke;
009import java.awt.Color;
010import java.awt.Composite;
011import java.awt.Graphics2D;
012import java.awt.LinearGradientPaint;
013import java.awt.MultipleGradientPaint;
014import java.awt.Paint;
015import java.awt.Point;
016import java.awt.Rectangle;
017import java.awt.RenderingHints;
018import java.awt.Stroke;
019import java.awt.image.BufferedImage;
020import java.awt.image.DataBufferInt;
021import java.awt.image.Raster;
022import java.io.BufferedReader;
023import java.io.IOException;
024import java.util.ArrayList;
025import java.util.Arrays;
026import java.util.Collections;
027import java.util.Date;
028import java.util.LinkedList;
029import java.util.List;
030import java.util.Objects;
031import java.util.Random;
032
033import javax.swing.ImageIcon;
034
035import org.openstreetmap.josm.data.Bounds;
036import org.openstreetmap.josm.data.SystemOfMeasurement;
037import org.openstreetmap.josm.data.SystemOfMeasurement.SoMChangeListener;
038import org.openstreetmap.josm.data.coor.LatLon;
039import org.openstreetmap.josm.data.gpx.GpxConstants;
040import org.openstreetmap.josm.data.gpx.GpxData;
041import org.openstreetmap.josm.data.gpx.GpxData.GpxDataChangeEvent;
042import org.openstreetmap.josm.data.gpx.GpxData.GpxDataChangeListener;
043import org.openstreetmap.josm.data.gpx.Line;
044import org.openstreetmap.josm.data.gpx.WayPoint;
045import org.openstreetmap.josm.data.preferences.NamedColorProperty;
046import org.openstreetmap.josm.gui.MapView;
047import org.openstreetmap.josm.gui.MapViewState;
048import org.openstreetmap.josm.gui.layer.GpxLayer;
049import org.openstreetmap.josm.gui.layer.MapViewGraphics;
050import org.openstreetmap.josm.gui.layer.MapViewPaintable;
051import org.openstreetmap.josm.gui.layer.MapViewPaintable.MapViewEvent;
052import org.openstreetmap.josm.gui.layer.MapViewPaintable.PaintableInvalidationEvent;
053import org.openstreetmap.josm.gui.layer.MapViewPaintable.PaintableInvalidationListener;
054import org.openstreetmap.josm.gui.preferences.display.GPXSettingsPanel;
055import org.openstreetmap.josm.io.CachedFile;
056import org.openstreetmap.josm.spi.preferences.Config;
057import org.openstreetmap.josm.tools.ColorScale;
058import org.openstreetmap.josm.tools.JosmRuntimeException;
059import org.openstreetmap.josm.tools.Logging;
060import org.openstreetmap.josm.tools.Utils;
061
062/**
063 * Class that helps to draw large set of GPS tracks with different colors and options
064 * @since 7319
065 */
066public class GpxDrawHelper implements SoMChangeListener, MapViewPaintable.LayerPainter, PaintableInvalidationListener, GpxDataChangeListener {
067
068    /**
069     * The default color property that is used for drawing GPX points.
070     * @since 15496
071     */
072    public static final NamedColorProperty DEFAULT_COLOR_PROPERTY = new NamedColorProperty(marktr("gps point"), Color.magenta);
073
074    private final GpxData data;
075    private final GpxLayer layer;
076
077    // draw lines between points belonging to different segments
078    private boolean forceLines;
079    // use alpha blending for line draw
080    private boolean alphaLines;
081    // draw direction arrows on the lines
082    private boolean arrows;
083    /** width of line for paint **/
084    private int lineWidth;
085    /** don't draw lines if longer than x meters **/
086    private int maxLineLength;
087    // draw lines
088    private boolean lines;
089    /** paint large dots for points **/
090    private boolean large;
091    private int largesize;
092    private boolean hdopCircle;
093    /** paint direction arrow with alternate math. may be faster **/
094    private boolean arrowsFast;
095    /** don't draw arrows nearer to each other than this **/
096    private int arrowsDelta;
097    private double minTrackDurationForTimeColoring;
098
099    /** maximum value of displayed HDOP, minimum is 0 */
100    private int hdoprange;
101
102    private static final double PHI = Utils.toRadians(15);
103
104    //// Variables used only to check cache validity
105    private boolean computeCacheInSync;
106    private int computeCacheMaxLineLengthUsed;
107    private Color computeCacheColorUsed;
108    private boolean computeCacheColorDynamic;
109    private ColorMode computeCacheColored;
110    private int computeCacheVelocityTune;
111    private int computeCacheHeatMapDrawColorTableIdx;
112    private boolean computeCacheHeatMapDrawPointMode;
113    private int computeCacheHeatMapDrawGain;
114    private int computeCacheHeatMapDrawLowerLimit;
115
116    private Color colorCache;
117    private Color colorCacheTransparent;
118
119    //// Color-related fields
120    /** Mode of the line coloring **/
121    private ColorMode colored;
122    /** max speed for coloring - allows to tweak line coloring for different speed levels. **/
123    private int velocityTune;
124    private boolean colorModeDynamic;
125    private Color neutralColor;
126    private int largePointAlpha;
127
128    // default access is used to allow changing from plugins
129    private ColorScale velocityScale;
130    /** Colors (without custom alpha channel, if given) for HDOP painting. **/
131    private ColorScale hdopScale;
132    private ColorScale qualityScale;
133    private ColorScale dateScale;
134    private ColorScale directionScale;
135
136    /** Opacity for hdop points **/
137    private int hdopAlpha;
138
139    // lookup array to draw arrows without doing any math
140    private static final int ll0 = 9;
141    private static final int sl4 = 5;
142    private static final int sl9 = 3;
143    private static final int[][] dir = {
144        {+sl4, +ll0, +ll0, +sl4}, {-sl9, +ll0, +sl9, +ll0},
145        {-ll0, +sl4, -sl4, +ll0}, {-ll0, -sl9, -ll0, +sl9},
146        {-sl4, -ll0, -ll0, -sl4}, {+sl9, -ll0, -sl9, -ll0},
147        {+ll0, -sl4, +sl4, -ll0}, {+ll0, +sl9, +ll0, -sl9}
148    };
149
150    /** heat map parameters **/
151
152    // draw small extra line
153    private boolean heatMapDrawExtraLine;
154    // used index for color table (parameter)
155    private int heatMapDrawColorTableIdx;
156    // use point or line draw mode
157    private boolean heatMapDrawPointMode;
158    // extra gain > 0 or < 0 attenuation, 0 = default
159    private int heatMapDrawGain;
160    // do not draw elements with value lower than this limit
161    private int heatMapDrawLowerLimit;
162
163    // normal buffered image and draw object (cached)
164    private BufferedImage heatMapImgGray;
165    private Graphics2D heatMapGraph2d;
166
167    // some cached values
168    Rectangle heatMapCacheScreenBounds = new Rectangle();
169    MapViewState heatMapMapViewState;
170    int heatMapCacheLineWith;
171
172    // copied value for line drawing
173    private final List<Integer> heatMapPolyX = new ArrayList<>();
174    private final List<Integer> heatMapPolyY = new ArrayList<>();
175
176    // setup color maps used by heat map
177    private static Color[] heatMapLutColorJosmInferno = createColorFromResource("inferno");
178    private static Color[] heatMapLutColorJosmViridis = createColorFromResource("viridis");
179    private static Color[] heatMapLutColorJosmBrown2Green = createColorFromResource("brown2green");
180    private static Color[] heatMapLutColorJosmRed2Blue = createColorFromResource("red2blue");
181
182    private static Color[] rtkLibQualityColors = new Color[] {
183        Color.GREEN, // Fixed, solution by carrier‐based relative positioning and the integer ambiguity is properly resolved.
184        Color.ORANGE, // Float, solution by carrier‐based relative positioning but the integer ambiguity is not resolved.
185        Color.PINK, // Reserved
186        Color.BLUE, // DGPS, solution by code‐based DGPS solutions or single point positioning with SBAS corrections
187        Color.RED, // Single, solution by single point positioning
188        Color.CYAN // PPP
189    };
190
191    // user defined heatmap color
192    private Color[] heatMapLutColor = createColorLut(0, Color.BLACK, Color.WHITE);
193
194    // The heat map was invalidated since the last draw.
195    private boolean gpxLayerInvalidated;
196
197    private void setupColors() {
198        hdopAlpha = Config.getPref().getInt("hdop.color.alpha", -1);
199        velocityScale = ColorScale.createHSBScale(256);
200        /** Colors (without custom alpha channel, if given) for HDOP painting. **/
201        hdopScale = ColorScale.createHSBScale(256).makeReversed().addTitle(tr("HDOP"));
202        qualityScale = ColorScale.createFixedScale(rtkLibQualityColors).addTitle(tr("Quality"));
203        dateScale = ColorScale.createHSBScale(256).addTitle(tr("Time"));
204        directionScale = ColorScale.createCyclicScale(256).setIntervalCount(4).addTitle(tr("Direction"));
205
206        systemOfMeasurementChanged(null, null);
207    }
208
209    @Override
210    public void systemOfMeasurementChanged(String oldSoM, String newSoM) {
211        SystemOfMeasurement som = SystemOfMeasurement.getSystemOfMeasurement();
212        velocityScale.addTitle(tr("Velocity, {0}", som.speedName));
213        layer.invalidate();
214    }
215
216    /**
217     * Different color modes
218     */
219    public enum ColorMode {
220        /**
221         * No special colors
222         */
223        NONE,
224        /**
225         * Color by velocity
226         */
227        VELOCITY,
228        /**
229         * Color by accuracy
230         */
231        HDOP,
232        /**
233         * Color by traveling direction
234         */
235        DIRECTION,
236        /**
237         * Color by time
238         */
239        TIME,
240        /**
241         * Color using a heatmap instead of normal lines
242         */
243        HEATMAP,
244        /**
245         * Color by quality (RTKLib)
246         */
247        QUALITY;
248
249        static ColorMode fromIndex(final int index) {
250            return values()[index];
251        }
252
253        int toIndex() {
254            return Arrays.asList(values()).indexOf(this);
255        }
256    }
257
258    /**
259     * Constructs a new {@code GpxDrawHelper}.
260     * @param gpxLayer The layer to draw
261     * @since 12157
262     */
263    public GpxDrawHelper(GpxLayer gpxLayer) {
264        layer = gpxLayer;
265        data = gpxLayer.data;
266        data.addChangeListener(this);
267
268        layer.addInvalidationListener(this);
269        SystemOfMeasurement.addSoMChangeListener(this);
270        setupColors();
271    }
272
273    /**
274     * Read coloring mode for specified layer from preferences
275     * @return coloring mode
276     */
277    public ColorMode getColorMode() {
278        try {
279            int i = optInt("colormode");
280            if (i == -1) i = 0; //global
281            return ColorMode.fromIndex(i);
282        } catch (IndexOutOfBoundsException e) {
283            Logging.warn(e);
284        }
285        return ColorMode.NONE;
286    }
287
288    private String opt(String key) {
289        return GPXSettingsPanel.getLayerPref(layer, key);
290    }
291
292    private boolean optBool(String key) {
293        return Boolean.parseBoolean(opt(key));
294    }
295
296    private int optInt(String key) {
297        return GPXSettingsPanel.getLayerPrefInt(layer, key);
298    }
299
300    /**
301     * Read all drawing-related settings from preferences
302     **/
303    public void readPreferences() {
304        forceLines = optBool("lines.force");
305        arrows = optBool("lines.arrows");
306        arrowsFast = optBool("lines.arrows.fast");
307        arrowsDelta = optInt("lines.arrows.min-distance");
308        lineWidth = optInt("lines.width");
309        alphaLines = optBool("lines.alpha-blend");
310
311        int l = optInt("lines");
312        if (!data.fromServer) {
313            maxLineLength = optInt("lines.max-length.local");
314            lines = l != 0; //draw for -1 (default), 1 (local) and 2 (all)
315        } else {
316            maxLineLength = optInt("lines.max-length");
317            lines = l == 2; //draw only for 2 (all)
318        }
319        large = optBool("points.large");
320        largesize = optInt("points.large.size");
321        hdopCircle = optBool("points.hdopcircle");
322        colored = getColorMode();
323        velocityTune = optInt("colormode.velocity.tune");
324        colorModeDynamic = optBool("colormode.dynamic-range");
325        /* good HDOP's are between 1 and 3, very bad HDOP's go into 3 digit values */
326        hdoprange = Config.getPref().getInt("hdop.range", 7);
327        minTrackDurationForTimeColoring = optInt("colormode.time.min-distance");
328        largePointAlpha = optInt("points.large.alpha") & 0xFF;
329
330        // get heatmap parameters
331        heatMapDrawExtraLine = optBool("colormode.heatmap.line-extra");
332        heatMapDrawColorTableIdx = optInt("colormode.heatmap.colormap");
333        heatMapDrawPointMode = optBool("colormode.heatmap.use-points");
334        heatMapDrawGain = optInt("colormode.heatmap.gain");
335        heatMapDrawLowerLimit = optInt("colormode.heatmap.lower-limit");
336
337        // shrink to range
338        heatMapDrawGain = Utils.clamp(heatMapDrawGain, -10, 10);
339        neutralColor = DEFAULT_COLOR_PROPERTY.get();
340        velocityScale.setNoDataColor(neutralColor);
341        dateScale.setNoDataColor(neutralColor);
342        hdopScale.setNoDataColor(neutralColor);
343        qualityScale.setNoDataColor(neutralColor);
344        directionScale.setNoDataColor(neutralColor);
345
346        largesize += lineWidth;
347    }
348
349    @Override
350    public void paint(MapViewGraphics graphics) {
351        Bounds clipBounds = graphics.getClipBounds().getLatLonBoundsBox();
352        List<WayPoint> visibleSegments = listVisibleSegments(clipBounds);
353        if (!visibleSegments.isEmpty()) {
354            readPreferences();
355            drawAll(graphics.getDefaultGraphics(), graphics.getMapView(), visibleSegments, clipBounds);
356            if (graphics.getMapView().getLayerManager().getActiveLayer() == layer) {
357                drawColorBar(graphics.getDefaultGraphics(), graphics.getMapView());
358            }
359        }
360    }
361
362    private List<WayPoint> listVisibleSegments(Bounds box) {
363        WayPoint last = null;
364        LinkedList<WayPoint> visibleSegments = new LinkedList<>();
365
366        ensureTrackVisibilityLength();
367        for (Line segment : data.getLinesIterable(layer.trackVisibility)) {
368
369            for (WayPoint pt : segment) {
370                Bounds b = new Bounds(pt.getCoor());
371                if (pt.drawLine && last != null) {
372                    b.extend(last.getCoor());
373                }
374                if (b.intersects(box)) {
375                    if (last != null && (visibleSegments.isEmpty()
376                            || visibleSegments.getLast() != last)) {
377                        if (last.drawLine) {
378                            WayPoint l = new WayPoint(last);
379                            l.drawLine = false;
380                            visibleSegments.add(l);
381                        } else {
382                            visibleSegments.add(last);
383                        }
384                    }
385                    visibleSegments.add(pt);
386                }
387                last = pt;
388            }
389        }
390        return visibleSegments;
391    }
392
393    /** ensures the trackVisibility array has the correct length without losing data.
394     * TODO: Make this nicer by syncing the trackVisibility automatically.
395     * additional entries are initialized to true;
396     */
397    private void ensureTrackVisibilityLength() {
398        final int l = data.getTracks().size();
399        if (l == layer.trackVisibility.length)
400            return;
401        final int m = Math.min(l, layer.trackVisibility.length);
402        layer.trackVisibility = Arrays.copyOf(layer.trackVisibility, l);
403        for (int i = m; i < l; i++) {
404            layer.trackVisibility[i] = true;
405        }
406    }
407
408    /**
409     * Draw all enabled GPX elements of layer.
410     * @param g               the common draw object to use
411     * @param mv              the meta data to current displayed area
412     * @param visibleSegments segments visible in the current scope of mv
413     * @param clipBounds      the clipping rectangle for the current view
414     * @since 14748 : new parameter clipBounds
415     */
416    public void drawAll(Graphics2D g, MapView mv, List<WayPoint> visibleSegments, Bounds clipBounds) {
417
418        final long timeStart = System.currentTimeMillis();
419
420        checkCache();
421
422        // STEP 2b - RE-COMPUTE CACHE DATA *********************
423        if (!computeCacheInSync) { // don't compute if the cache is good
424            calculateColors();
425            // update the WaiPoint.drawline attributes
426            visibleSegments.clear();
427            visibleSegments.addAll(listVisibleSegments(clipBounds));
428        }
429
430        fixColors(visibleSegments);
431
432        // backup the environment
433        Composite oldComposite = g.getComposite();
434        Stroke oldStroke = g.getStroke();
435        Paint oldPaint = g.getPaint();
436
437        // set hints for the render
438        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
439            Config.getPref().getBoolean("mappaint.gpx.use-antialiasing", false) ?
440                    RenderingHints.VALUE_ANTIALIAS_ON : RenderingHints.VALUE_ANTIALIAS_OFF);
441
442        if (lineWidth > 0) {
443            g.setStroke(new BasicStroke(lineWidth, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
444        }
445
446        // global enabled or select via color
447        boolean useHeatMap = ColorMode.HEATMAP == colored;
448
449        // default global alpha level
450        float layerAlpha = 1.00f;
451
452        // extract current alpha blending value
453        if (oldComposite instanceof AlphaComposite) {
454            layerAlpha = ((AlphaComposite) oldComposite).getAlpha();
455        }
456
457        // use heatmap background layer
458        if (useHeatMap) {
459            drawHeatMap(g, mv, visibleSegments);
460        } else {
461            // use normal line style or alpha-blending lines
462            if (!alphaLines) {
463                drawLines(g, mv, visibleSegments);
464            } else {
465                drawLinesAlpha(g, mv, visibleSegments, layerAlpha);
466            }
467        }
468
469        // override global alpha settings (smooth overlay)
470        if (alphaLines || useHeatMap) {
471            g.setComposite(AlphaComposite.SrcOver.derive(0.25f * layerAlpha));
472        }
473
474        // normal overlays
475        drawArrows(g, mv, visibleSegments);
476        drawPoints(g, mv, visibleSegments);
477
478        // restore environment
479        g.setPaint(oldPaint);
480        g.setStroke(oldStroke);
481        g.setComposite(oldComposite);
482
483        // show some debug info
484        if (Logging.isDebugEnabled() && !visibleSegments.isEmpty()) {
485            final long timeDiff = System.currentTimeMillis() - timeStart;
486
487            Logging.debug("gpxdraw::draw takes " +
488                         Utils.getDurationString(timeDiff) +
489                         "(" +
490                         "segments= " + visibleSegments.size() +
491                         ", per 10000 = " + Utils.getDurationString(10_000 * timeDiff / visibleSegments.size()) +
492                         ")"
493              );
494        }
495    }
496
497    /**
498     *  Calculate colors of way segments based on latest configuration settings
499     */
500    public void calculateColors() {
501        double minval = +1e10;
502        double maxval = -1e10;
503        WayPoint oldWp = null;
504
505        if (colorModeDynamic) {
506            if (colored == ColorMode.VELOCITY) {
507                final List<Double> velocities = new ArrayList<>();
508                for (Line segment : data.getLinesIterable(null)) {
509                    if (!forceLines) {
510                        oldWp = null;
511                    }
512                    for (WayPoint trkPnt : segment) {
513                        if (!trkPnt.isLatLonKnown()) {
514                            continue;
515                        }
516                        if (oldWp != null && trkPnt.getTimeInMillis() > oldWp.getTimeInMillis()) {
517                            double vel = trkPnt.getCoor().greatCircleDistance(oldWp.getCoor())
518                                    / (trkPnt.getTime() - oldWp.getTime());
519                            velocities.add(vel);
520                        }
521                        oldWp = trkPnt;
522                    }
523                }
524                Collections.sort(velocities);
525                if (velocities.isEmpty()) {
526                    velocityScale.setRange(0, 120/3.6);
527                } else {
528                    minval = velocities.get(velocities.size() / 20); // 5% percentile to remove outliers
529                    maxval = velocities.get(velocities.size() * 19 / 20); // 95% percentile to remove outliers
530                    velocityScale.setRange(minval, maxval);
531                }
532            } else if (colored == ColorMode.HDOP) {
533                for (Line segment : data.getLinesIterable(null)) {
534                    for (WayPoint trkPnt : segment) {
535                        Object val = trkPnt.get(GpxConstants.PT_HDOP);
536                        if (val != null) {
537                            double hdop = ((Float) val).doubleValue();
538                            if (hdop > maxval) {
539                                maxval = hdop;
540                            }
541                            if (hdop < minval) {
542                                minval = hdop;
543                            }
544                        }
545                    }
546                }
547                if (minval >= maxval) {
548                    hdopScale.setRange(0, 100);
549                } else {
550                    hdopScale.setRange(minval, maxval);
551                }
552            }
553            oldWp = null;
554        } else { // color mode not dynamic
555            velocityScale.setRange(0, velocityTune);
556            hdopScale.setRange(0, hdoprange);
557            qualityScale.setRange(1, rtkLibQualityColors.length);
558        }
559        double now = System.currentTimeMillis()/1000.0;
560        if (colored == ColorMode.TIME) {
561            Date[] bounds = data.getMinMaxTimeForAllTracks();
562            if (bounds.length >= 2) {
563                minval = bounds[0].getTime()/1000.0;
564                maxval = bounds[1].getTime()/1000.0;
565            } else {
566                minval = 0;
567                maxval = now;
568            }
569            dateScale.setRange(minval, maxval);
570        }
571
572        // Now the colors for all the points will be assigned
573        for (Line segment : data.getLinesIterable(null)) {
574            if (!forceLines) { // don't draw lines between segments, unless forced to
575                oldWp = null;
576            }
577            for (WayPoint trkPnt : segment) {
578                LatLon c = trkPnt.getCoor();
579                trkPnt.customColoring = segment.getColor();
580                if (Double.isNaN(c.lat()) || Double.isNaN(c.lon())) {
581                    continue;
582                }
583                // now we are sure some color will be assigned
584                Color color = null;
585
586                if (colored == ColorMode.HDOP) {
587                    color = hdopScale.getColor((Float) trkPnt.get(GpxConstants.PT_HDOP));
588                } else if (colored == ColorMode.QUALITY) {
589                    color = qualityScale.getColor((Integer) trkPnt.get(GpxConstants.RTKLIB_Q));
590                }
591                if (oldWp != null) { // other coloring modes need segment for calcuation
592                    double dist = c.greatCircleDistance(oldWp.getCoor());
593                    boolean noDraw = false;
594                    switch (colored) {
595                    case VELOCITY:
596                        double dtime = trkPnt.getTime() - oldWp.getTime();
597                        if (dtime > 0) {
598                            color = velocityScale.getColor(dist / dtime);
599                        } else {
600                            color = velocityScale.getNoDataColor();
601                        }
602                        break;
603                    case DIRECTION:
604                        double dirColor = oldWp.getCoor().bearing(trkPnt.getCoor());
605                        color = directionScale.getColor(dirColor);
606                        break;
607                    case TIME:
608                        double t = trkPnt.getTime();
609                        // skip bad timestamps and very short tracks
610                        if (t > 0 && t <= now && maxval - minval > minTrackDurationForTimeColoring) {
611                            color = dateScale.getColor(t);
612                        } else {
613                            color = dateScale.getNoDataColor();
614                        }
615                        break;
616                    default: // Do nothing
617                    }
618                    if (!noDraw && (!segment.isUnordered() || !data.fromServer) && (maxLineLength == -1 || dist <= maxLineLength)) {
619                        trkPnt.drawLine = true;
620                        double bearing = oldWp.getCoor().bearing(trkPnt.getCoor());
621                        trkPnt.dir = ((int) (bearing / Math.PI * 4 + 1.5)) % 8;
622                    } else {
623                        trkPnt.drawLine = false;
624                    }
625                } else { // make sure we reset outdated data
626                    trkPnt.drawLine = false;
627                    color = segment.getColor();
628                }
629                if (color != null) {
630                    trkPnt.customColoring = color;
631                }
632                oldWp = trkPnt;
633            }
634        }
635
636        // heat mode
637        if (ColorMode.HEATMAP == colored) {
638
639            // get new user color map and refresh visibility level
640            heatMapLutColor = createColorLut(heatMapDrawLowerLimit,
641                                             selectColorMap(neutralColor != null ? neutralColor : Color.WHITE, heatMapDrawColorTableIdx));
642
643            // force redraw of image
644            heatMapMapViewState = null;
645        }
646
647        computeCacheInSync = true;
648    }
649
650    /**
651     * Draw all GPX ways segments
652     * @param g               the common draw object to use
653     * @param mv              the meta data to current displayed area
654     * @param visibleSegments segments visible in the current scope of mv
655     */
656    private void drawLines(Graphics2D g, MapView mv, List<WayPoint> visibleSegments) {
657        if (lines) {
658            Point old = null;
659            for (WayPoint trkPnt : visibleSegments) {
660                if (!trkPnt.isLatLonKnown()) {
661                    old = null;
662                    continue;
663                }
664                Point screen = mv.getPoint(trkPnt);
665                // skip points that are on the same screenposition
666                if (trkPnt.drawLine && old != null && ((old.x != screen.x) || (old.y != screen.y))) {
667                    g.setColor(trkPnt.customColoring);
668                    g.drawLine(old.x, old.y, screen.x, screen.y);
669                }
670                old = screen;
671            }
672        }
673    }
674
675    /**
676     * Draw all GPX arrays
677     * @param g               the common draw object to use
678     * @param mv              the meta data to current displayed area
679     * @param visibleSegments segments visible in the current scope of mv
680     */
681    private void drawArrows(Graphics2D g, MapView mv, List<WayPoint> visibleSegments) {
682        /****************************************************************
683         ********** STEP 3b - DRAW NICE ARROWS **************************
684         ****************************************************************/
685        if (lines && arrows && !arrowsFast) {
686            Point old = null;
687            Point oldA = null; // last arrow painted
688            for (WayPoint trkPnt : visibleSegments) {
689                if (!trkPnt.isLatLonKnown()) {
690                    old = null;
691                    continue;
692                }
693                if (trkPnt.drawLine) {
694                    Point screen = mv.getPoint(trkPnt);
695                    // skip points that are on the same screenposition
696                    if (old != null
697                            && (oldA == null || screen.x < oldA.x - arrowsDelta || screen.x > oldA.x + arrowsDelta
698                            || screen.y < oldA.y - arrowsDelta || screen.y > oldA.y + arrowsDelta)) {
699                        g.setColor(trkPnt.customColoring);
700                        double t = Math.atan2((double) screen.y - old.y, (double) screen.x - old.x) + Math.PI;
701                        g.drawLine(screen.x, screen.y, (int) (screen.x + 10 * Math.cos(t - PHI)),
702                                (int) (screen.y + 10 * Math.sin(t - PHI)));
703                        g.drawLine(screen.x, screen.y, (int) (screen.x + 10 * Math.cos(t + PHI)),
704                                (int) (screen.y + 10 * Math.sin(t + PHI)));
705                        oldA = screen;
706                    }
707                    old = screen;
708                }
709            } // end for trkpnt
710        }
711
712        /****************************************************************
713         ********** STEP 3c - DRAW FAST ARROWS **************************
714         ****************************************************************/
715        if (lines && arrows && arrowsFast) {
716            Point old = null;
717            Point oldA = null; // last arrow painted
718            for (WayPoint trkPnt : visibleSegments) {
719                LatLon c = trkPnt.getCoor();
720                if (Double.isNaN(c.lat()) || Double.isNaN(c.lon())) {
721                    continue;
722                }
723                if (trkPnt.drawLine) {
724                    Point screen = mv.getPoint(trkPnt);
725                    // skip points that are on the same screenposition
726                    if (old != null
727                            && (oldA == null || screen.x < oldA.x - arrowsDelta || screen.x > oldA.x + arrowsDelta
728                            || screen.y < oldA.y - arrowsDelta || screen.y > oldA.y + arrowsDelta)) {
729                        g.setColor(trkPnt.customColoring);
730                        g.drawLine(screen.x, screen.y, screen.x + dir[trkPnt.dir][0], screen.y
731                                + dir[trkPnt.dir][1]);
732                        g.drawLine(screen.x, screen.y, screen.x + dir[trkPnt.dir][2], screen.y
733                                + dir[trkPnt.dir][3]);
734                        oldA = screen;
735                    }
736                    old = screen;
737                }
738            } // end for trkpnt
739        }
740    }
741
742    /**
743     * Draw all GPX points
744     * @param g               the common draw object to use
745     * @param mv              the meta data to current displayed area
746     * @param visibleSegments segments visible in the current scope of mv
747     */
748    private void drawPoints(Graphics2D g, MapView mv, List<WayPoint> visibleSegments) {
749        /****************************************************************
750         ********** STEP 3d - DRAW LARGE POINTS AND HDOP CIRCLE *********
751         ****************************************************************/
752        if (large || hdopCircle) {
753            final int halfSize = largesize/2;
754            for (WayPoint trkPnt : visibleSegments) {
755                LatLon c = trkPnt.getCoor();
756                if (Double.isNaN(c.lat()) || Double.isNaN(c.lon())) {
757                    continue;
758                }
759                Point screen = mv.getPoint(trkPnt);
760
761                if (hdopCircle && trkPnt.get(GpxConstants.PT_HDOP) != null) {
762                    // hdop value
763                    float hdop = (Float) trkPnt.get(GpxConstants.PT_HDOP);
764                    if (hdop < 0) {
765                        hdop = 0;
766                    }
767                    Color customColoringTransparent = hdopAlpha < 0 ? trkPnt.customColoring :
768                        new Color((trkPnt.customColoring.getRGB() & 0x00ffffff) | (hdopAlpha << 24), true);
769                    g.setColor(customColoringTransparent);
770                    // hdop circles
771                    int hdopp = mv.getPoint(new LatLon(
772                            trkPnt.getCoor().lat(),
773                            trkPnt.getCoor().lon() + 2d*6*hdop*360/40000000d)).x - screen.x;
774                    g.drawArc(screen.x-hdopp/2, screen.y-hdopp/2, hdopp, hdopp, 0, 360);
775                }
776                if (large) {
777                    // color the large GPS points like the gps lines
778                    if (trkPnt.customColoring != null) {
779                        if (trkPnt.customColoring.equals(colorCache) && colorCacheTransparent != null) {
780                            g.setColor(colorCacheTransparent);
781                        } else {
782                            Color customColoringTransparent = largePointAlpha < 0 ? trkPnt.customColoring :
783                                new Color((trkPnt.customColoring.getRGB() & 0x00ffffff) | (largePointAlpha << 24), true);
784
785                            g.setColor(customColoringTransparent);
786                            colorCache = trkPnt.customColoring;
787                            colorCacheTransparent = customColoringTransparent;
788                        }
789                    }
790                    g.fillRect(screen.x-halfSize, screen.y-halfSize, largesize, largesize);
791                }
792            } // end for trkpnt
793        } // end if large || hdopcircle
794
795        /****************************************************************
796         ********** STEP 3e - DRAW SMALL POINTS FOR LINES ***************
797         ****************************************************************/
798        if (!large && lines) {
799            g.setColor(neutralColor);
800            for (WayPoint trkPnt : visibleSegments) {
801                LatLon c = trkPnt.getCoor();
802                if (Double.isNaN(c.lat()) || Double.isNaN(c.lon())) {
803                    continue;
804                }
805                if (!trkPnt.drawLine) {
806                    g.setColor(trkPnt.customColoring);
807                    Point screen = mv.getPoint(trkPnt);
808                    g.drawRect(screen.x, screen.y, 0, 0);
809                }
810            } // end for trkpnt
811        } // end if large
812
813        /****************************************************************
814         ********** STEP 3f - DRAW SMALL POINTS INSTEAD OF LINES ********
815         ****************************************************************/
816        if (!large && !lines) {
817            g.setColor(neutralColor);
818            for (WayPoint trkPnt : visibleSegments) {
819                LatLon c = trkPnt.getCoor();
820                if (Double.isNaN(c.lat()) || Double.isNaN(c.lon())) {
821                    continue;
822                }
823                Point screen = mv.getPoint(trkPnt);
824                g.setColor(trkPnt.customColoring);
825                g.drawRect(screen.x, screen.y, 0, 0);
826            } // end for trkpnt
827        } // end if large
828    }
829
830    /**
831     * Draw GPX lines by using alpha blending
832     * @param g               the common draw object to use
833     * @param mv              the meta data to current displayed area
834     * @param visibleSegments segments visible in the current scope of mv
835     * @param layerAlpha      the color alpha value set for that operation
836     */
837    private void drawLinesAlpha(Graphics2D g, MapView mv, List<WayPoint> visibleSegments, float layerAlpha) {
838
839        // 1st. backup the paint environment ----------------------------------
840        Composite oldComposite = g.getComposite();
841        Stroke oldStroke = g.getStroke();
842        Paint oldPaint = g.getPaint();
843
844        // 2nd. determine current scale factors -------------------------------
845
846        // adjust global settings
847        final int globalLineWidth = Utils.clamp(lineWidth, 1, 20);
848
849        // cache scale of view
850        final double zoomScale = mv.getDist100Pixel() / 50.0f;
851
852        // 3rd. determine current paint parameters -----------------------------
853
854        // alpha value is based on zoom and line with combined with global layer alpha
855        float theLineAlpha = (float) Utils.clamp((0.50 / zoomScale) / (globalLineWidth + 1), 0.01, 0.50) * layerAlpha;
856        final int theLineWith = (int) (lineWidth / zoomScale) + 1;
857
858        // 4th setup virtual paint area ----------------------------------------
859
860        // set line format and alpha channel for all overlays (more lines -> few overlap -> more transparency)
861        g.setStroke(new BasicStroke(theLineWith, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
862        g.setComposite(AlphaComposite.SrcOver.derive(theLineAlpha));
863
864        // last used / calculated entries
865        Point lastPaintPnt = null;
866
867        // 5th draw the layer ---------------------------------------------------
868
869        // for all points
870        for (WayPoint trkPnt : visibleSegments) {
871
872            // transform coordinates
873            final Point paintPnt = mv.getPoint(trkPnt);
874
875            // skip single points
876            if (lastPaintPnt != null && trkPnt.drawLine && !lastPaintPnt.equals(paintPnt)) {
877
878                // set different color
879                g.setColor(trkPnt.customColoring);
880
881                // draw it
882                g.drawLine(lastPaintPnt.x, lastPaintPnt.y, paintPnt.x, paintPnt.y);
883            }
884
885            lastPaintPnt = paintPnt;
886        }
887
888        // @last restore modified paint environment -----------------------------
889        g.setPaint(oldPaint);
890        g.setStroke(oldStroke);
891        g.setComposite(oldComposite);
892    }
893
894    /**
895     * Generates a linear gradient map image
896     *
897     * @param width  image width
898     * @param height image height
899     * @param colors 1..n color descriptions
900     * @return image object
901     */
902    protected static BufferedImage createImageGradientMap(int width, int height, Color... colors) {
903
904        // create image an paint object
905        final BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
906        final Graphics2D g = img.createGraphics();
907
908        float[] fract = new float[ colors.length ];
909
910        // distribute fractions (define position of color in map)
911        for (int i = 0; i < colors.length; ++i) {
912            fract[i] = i * (1.0f / colors.length);
913        }
914
915        // draw the gradient map
916        LinearGradientPaint gradient = new LinearGradientPaint(0, 0, width, height, fract, colors,
917                                                               MultipleGradientPaint.CycleMethod.NO_CYCLE);
918        g.setPaint(gradient);
919        g.fillRect(0, 0, width, height);
920        g.dispose();
921
922        // access it via raw interface
923        return img;
924    }
925
926    /**
927     * Creates a distributed colormap by linear blending between colors
928     * @param lowerLimit lower limit for first visible color
929     * @param colors 1..n colors
930     * @return array of Color objects
931     */
932    protected static Color[] createColorLut(int lowerLimit, Color... colors) {
933
934        // number of lookup entries
935        final int tableSize = 256;
936
937        // access it via raw interface
938        final Raster imgRaster = createImageGradientMap(tableSize, 1, colors).getData();
939
940        // the pixel storage
941        int[] pixel = new int[1];
942
943        Color[] colorTable = new Color[tableSize];
944
945        // map the range 0..255 to 0..pi/2
946        final double mapTo90Deg = Math.PI / 2.0 / 255.0;
947
948        // create the lookup table
949        for (int i = 0; i < tableSize; i++) {
950
951            // get next single pixel
952            imgRaster.getDataElements(i, 0, pixel);
953
954            // get color and map
955            Color c = new Color(pixel[0]);
956
957            // smooth alpha like sin curve
958            int alpha = (i > lowerLimit) ? (int) (Math.sin((i-lowerLimit) * mapTo90Deg) * 255) : 0;
959
960            // alpha with pre-offset, first color -> full transparent
961            alpha = alpha > 0 ? (20 + alpha) : 0;
962
963            // shrink to maximum bound
964            if (alpha > 255) {
965                alpha = 255;
966            }
967
968            // increase transparency for higher values ( avoid big saturation )
969            if (i > 240 && 255 == alpha) {
970                alpha -= (i - 240);
971            }
972
973            // fill entry in table, assign a alpha value
974            colorTable[i] = new Color(c.getRed(), c.getGreen(), c.getBlue(), alpha);
975        }
976
977        // transform into lookup table
978        return colorTable;
979    }
980
981    /**
982     * Creates a darker color
983     * @param in        Color object
984     * @param adjust    darker adjustment amount
985     * @return          new Color
986     */
987    protected static Color darkerColor(Color in, float adjust) {
988
989        final float r = (float) in.getRed()/255;
990        final float g = (float) in.getGreen()/255;
991        final float b = (float) in.getBlue()/255;
992
993        return new Color(r*adjust, g*adjust, b*adjust);
994    }
995
996    /**
997     * Creates a colormap by using a static color map with 1..n colors (RGB 0.0 ..1.0)
998     * @param str the filename (without extension) to look for into data/gpx
999     * @return the parsed colormap
1000     */
1001    protected static Color[] createColorFromResource(String str) {
1002
1003        // create resource string
1004        final String colorFile = "resource://data/gpx/" + str + ".txt";
1005
1006        List<Color> colorList = new ArrayList<>();
1007
1008        // try to load the file
1009        try (CachedFile cf = new CachedFile(colorFile); BufferedReader br = cf.getContentReader()) {
1010
1011            String line;
1012
1013            // process lines
1014            while ((line = br.readLine()) != null) {
1015
1016                // use comma as separator
1017                String[] column = line.split(",");
1018
1019                // empty or comment line
1020                if (column.length < 3 || column[0].startsWith("#")) {
1021                    continue;
1022                }
1023
1024                // extract RGB value
1025                float r = Float.parseFloat(column[0]);
1026                float g = Float.parseFloat(column[1]);
1027                float b = Float.parseFloat(column[2]);
1028
1029                // some color tables are 0..1.0 and some 0.255
1030                float scale = (r < 1 && g < 1 && b < 1) ? 1 : 255;
1031
1032                colorList.add(new Color(r/scale, g/scale, b/scale));
1033            }
1034        } catch (IOException e) {
1035            throw new JosmRuntimeException(e);
1036        }
1037
1038        // fallback if empty or failed
1039        if (colorList.isEmpty()) {
1040            colorList.add(Color.BLACK);
1041            colorList.add(Color.WHITE);
1042        } else {
1043            // add additional darker elements to end of list
1044            final Color lastColor = colorList.get(colorList.size() - 1);
1045            colorList.add(darkerColor(lastColor, 0.975f));
1046            colorList.add(darkerColor(lastColor, 0.950f));
1047        }
1048
1049        return createColorLut(0, colorList.toArray(new Color[0]));
1050    }
1051
1052    /**
1053     * Returns the next user color map
1054     *
1055     * @param userColor - default or fallback user color
1056     * @param tableIdx  - selected user color index
1057     * @return color array
1058     */
1059    protected static Color[] selectColorMap(Color userColor, int tableIdx) {
1060
1061        // generate new user color map ( dark, user color, white )
1062        Color[] userColor1 = createColorLut(0, userColor.darker(), userColor, userColor.brighter(), Color.WHITE);
1063
1064        // generate new user color map ( white -> color )
1065        Color[] userColor2 = createColorLut(0, Color.WHITE, Color.WHITE, userColor);
1066
1067        // generate new user color map
1068        Color[] colorTrafficLights = createColorLut(0, Color.WHITE, Color.GREEN.darker(), Color.YELLOW, Color.RED);
1069
1070        // decide what, keep order is sync with setting on GUI
1071        Color[][] lut = {
1072                userColor1,
1073                userColor2,
1074                colorTrafficLights,
1075                heatMapLutColorJosmInferno,
1076                heatMapLutColorJosmViridis,
1077                heatMapLutColorJosmBrown2Green,
1078                heatMapLutColorJosmRed2Blue
1079        };
1080
1081        // default case
1082        Color[] nextUserColor = userColor1;
1083
1084        // select by index
1085        if (tableIdx < lut.length) {
1086            nextUserColor = lut[ tableIdx ];
1087        }
1088
1089        // adjust color map
1090        return nextUserColor;
1091    }
1092
1093    /**
1094     * Generates a Icon
1095     *
1096     * @param userColor selected user color
1097     * @param tableIdx tabled index
1098     * @param size size of the image
1099     * @return a image icon that shows the
1100     */
1101    public static ImageIcon getColorMapImageIcon(Color userColor, int tableIdx, int size) {
1102        return new ImageIcon(createImageGradientMap(size, size, selectColorMap(userColor, tableIdx)));
1103    }
1104
1105    /**
1106     * Draw gray heat map with current Graphics2D setting
1107     * @param gB              the common draw object to use
1108     * @param mv              the meta data to current displayed area
1109     * @param listSegm        segments visible in the current scope of mv
1110     * @param foreComp        composite use to draw foreground objects
1111     * @param foreStroke      stroke use to draw foreground objects
1112     * @param backComp        composite use to draw background objects
1113     * @param backStroke      stroke use to draw background objects
1114     */
1115    private void drawHeatGrayLineMap(Graphics2D gB, MapView mv, List<WayPoint> listSegm,
1116                                     Composite foreComp, Stroke foreStroke,
1117                                     Composite backComp, Stroke backStroke) {
1118
1119        // draw foreground
1120        boolean drawForeground = foreComp != null && foreStroke != null;
1121
1122        // set initial values
1123        gB.setStroke(backStroke); gB.setComposite(backComp);
1124
1125        // get last point in list
1126        final WayPoint lastPnt = !listSegm.isEmpty() ? listSegm.get(listSegm.size() - 1) : null;
1127
1128        // for all points, draw single lines by using optimized drawing
1129        for (WayPoint trkPnt : listSegm) {
1130
1131            // get transformed coordinates
1132            final Point paintPnt = mv.getPoint(trkPnt);
1133
1134            // end of line segment or end of list reached
1135            if (!trkPnt.drawLine || (lastPnt == trkPnt)) {
1136
1137                // convert to primitive type
1138                final int[] polyXArr = heatMapPolyX.stream().mapToInt(Integer::intValue).toArray();
1139                final int[] polyYArr = heatMapPolyY.stream().mapToInt(Integer::intValue).toArray();
1140
1141                // a.) draw background
1142                gB.drawPolyline(polyXArr, polyYArr, polyXArr.length);
1143
1144                // b.) draw extra foreground
1145                if (drawForeground && heatMapDrawExtraLine) {
1146
1147                    gB.setStroke(foreStroke); gB.setComposite(foreComp);
1148                    gB.drawPolyline(polyXArr, polyYArr, polyXArr.length);
1149                    gB.setStroke(backStroke); gB.setComposite(backComp);
1150                }
1151
1152                // drop used points
1153                heatMapPolyX.clear(); heatMapPolyY.clear();
1154            }
1155
1156            // store only the integer part (make sense because pixel is 1:1 here)
1157            heatMapPolyX.add((int) paintPnt.getX());
1158            heatMapPolyY.add((int) paintPnt.getY());
1159        }
1160    }
1161
1162    /**
1163     * Map the gray map to heat map and draw them with current Graphics2D setting
1164     * @param g               the common draw object to use
1165     * @param imgGray         gray scale input image
1166     * @param sampleRaster    the line with for drawing
1167     * @param outlineWidth     line width for outlines
1168     */
1169    private void drawHeatMapGrayMap(Graphics2D g, BufferedImage imgGray, int sampleRaster, int outlineWidth) {
1170
1171        final int[] imgPixels = ((DataBufferInt) imgGray.getRaster().getDataBuffer()).getData();
1172
1173        // samples offset and bounds are scaled with line width derived from zoom level
1174        final int offX = Math.max(1, sampleRaster);
1175        final int offY = Math.max(1, sampleRaster);
1176
1177        final int maxPixelX = imgGray.getWidth();
1178        final int maxPixelY = imgGray.getHeight();
1179
1180        // always full or outlines at big samples rasters
1181        final boolean drawOutlines = (outlineWidth > 0) && ((0 == sampleRaster) || (sampleRaster > 10));
1182
1183        // backup stroke
1184        final Stroke oldStroke = g.getStroke();
1185
1186        // use basic stroke for outlines and default transparency
1187        g.setStroke(new BasicStroke(outlineWidth));
1188
1189        int lastPixelX = 0;
1190        int lastPixelColor = 0;
1191
1192        // resample gray scale image with line linear weight of next sample in line
1193        // process each line and draw pixels / rectangles with same color with one operations
1194        for (int y = 0; y < maxPixelY; y += offY) {
1195
1196            // the lines offsets
1197            final int lastLineOffset = maxPixelX * (y+0);
1198            final int nextLineOffset = maxPixelX * (y+1);
1199
1200            for (int x = 0; x < maxPixelX; x += offX) {
1201
1202                int thePixelColor = 0; int thePixelCount = 0;
1203
1204                // sample the image (it is gray scale)
1205                int offset = lastLineOffset + x;
1206
1207                // merge next pixels of window of line
1208                for (int k = 0; k < offX && (offset + k) < nextLineOffset; k++) {
1209                    thePixelColor += imgPixels[offset+k] & 0xFF;
1210                    thePixelCount++;
1211                }
1212
1213                // mean value
1214                thePixelColor = thePixelCount > 0 ? (thePixelColor / thePixelCount) : 0;
1215
1216                // restart -> use initial sample
1217                if (0 == x) {
1218                    lastPixelX = 0; lastPixelColor = thePixelColor - 1;
1219                }
1220
1221                boolean bDrawIt = false;
1222
1223                // when one of segment is mapped to black
1224                bDrawIt = bDrawIt || (lastPixelColor == 0) || (thePixelColor == 0);
1225
1226                // different color
1227                bDrawIt = bDrawIt || (Math.abs(lastPixelColor-thePixelColor) > 0);
1228
1229                // when line is finished draw always
1230                bDrawIt = bDrawIt || (y >= (maxPixelY-offY));
1231
1232                if (bDrawIt) {
1233
1234                    // draw only foreground pixels
1235                    if (lastPixelColor > 0) {
1236
1237                        // gray to RGB mapping
1238                        g.setColor(heatMapLutColor[ lastPixelColor ]);
1239
1240                        // box from from last Y pixel to current pixel
1241                        if (drawOutlines) {
1242                            g.drawRect(lastPixelX, y, offX + x - lastPixelX, offY);
1243                        } else {
1244                            g.fillRect(lastPixelX, y, offX + x - lastPixelX, offY);
1245                        }
1246                    }
1247
1248                    // restart detection
1249                    lastPixelX = x; lastPixelColor = thePixelColor;
1250                }
1251            }
1252        }
1253
1254        // recover
1255        g.setStroke(oldStroke);
1256    }
1257
1258    /**
1259     * Collect and draw GPS segments and displays a heat-map
1260     * @param g               the common draw object to use
1261     * @param mv              the meta data to current displayed area
1262     * @param visibleSegments segments visible in the current scope of mv
1263     */
1264    private void drawHeatMap(Graphics2D g, MapView mv, List<WayPoint> visibleSegments) {
1265
1266        // get bounds of screen image and projection, zoom and adjust input parameters
1267        final Rectangle screenBounds = new Rectangle(mv.getWidth(), mv.getHeight());
1268        final MapViewState mapViewState = mv.getState();
1269        final double zoomScale = mv.getDist100Pixel() / 50.0f;
1270
1271        // adjust global settings ( zero = default line width )
1272        final int globalLineWidth = (0 == lineWidth) ? 1 : Utils.clamp(lineWidth, 1, 20);
1273
1274        // 1st setup virtual paint area ----------------------------------------
1275
1276        // new image buffer needed
1277        final boolean imageSetup = null == heatMapImgGray || !heatMapCacheScreenBounds.equals(screenBounds);
1278
1279        // screen bounds changed, need new image buffer ?
1280        if (imageSetup) {
1281            // we would use a "pure" grayscale image, but there is not efficient way to map gray scale values to RGB)
1282            heatMapImgGray = new BufferedImage(screenBounds.width, screenBounds.height, BufferedImage.TYPE_INT_ARGB);
1283            heatMapGraph2d = heatMapImgGray.createGraphics();
1284            heatMapGraph2d.setBackground(new Color(0, 0, 0, 255));
1285            heatMapGraph2d.setColor(Color.WHITE);
1286
1287            // fast draw ( maybe help or not )
1288            heatMapGraph2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF);
1289            heatMapGraph2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_SPEED);
1290            heatMapGraph2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_SPEED);
1291            heatMapGraph2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_DISABLE);
1292            heatMapGraph2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
1293            heatMapGraph2d.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
1294            heatMapGraph2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_SPEED);
1295
1296            // cache it
1297            heatMapCacheScreenBounds = screenBounds;
1298        }
1299
1300        // 2nd. determine current scale factors -------------------------------
1301
1302        // the line width (foreground: draw extra small footprint line of track)
1303        int lineWidthB = (int) Math.max(1.5f * (globalLineWidth / zoomScale) + 1, 2);
1304        int lineWidthF = lineWidthB > 2 ? (globalLineWidth - 1) : 0;
1305
1306        // global alpha adjustment
1307        float lineAlpha = (float) Utils.clamp((0.40 / zoomScale) / (globalLineWidth + 1), 0.01, 0.40);
1308
1309        // adjust 0.15 .. 1.85
1310        float scaleAlpha = 1.0f + ((heatMapDrawGain/10.0f) * 0.85f);
1311
1312        // add to calculated values
1313        float lineAlphaBPoint = (float) Utils.clamp((lineAlpha * 0.65) * scaleAlpha, 0.001, 0.90);
1314        float lineAlphaBLine = (float) Utils.clamp((lineAlpha * 1.00) * scaleAlpha, 0.001, 0.90);
1315        float lineAlphaFLine = (float) Utils.clamp((lineAlpha / 1.50) * scaleAlpha, 0.001, 0.90);
1316
1317        // 3rd Calculate the heat map data by draw GPX traces with alpha value ----------
1318
1319        // recalculation of image needed
1320        final boolean imageRecalc = !mapViewState.equalsInWindow(heatMapMapViewState)
1321                || gpxLayerInvalidated
1322                || heatMapCacheLineWith != globalLineWidth;
1323
1324        // need re-generation of gray image ?
1325        if (imageSetup || imageRecalc) {
1326
1327            // clear background
1328            heatMapGraph2d.clearRect(0, 0, heatMapImgGray.getWidth(), heatMapImgGray.getHeight());
1329
1330            // point or line blending
1331            if (heatMapDrawPointMode) {
1332                heatMapGraph2d.setComposite(AlphaComposite.SrcOver.derive(lineAlphaBPoint));
1333                drawHeatGrayDotMap(heatMapGraph2d, mv, visibleSegments, lineWidthB);
1334
1335            } else {
1336                drawHeatGrayLineMap(heatMapGraph2d, mv, visibleSegments,
1337                                    lineWidthF > 1 ? AlphaComposite.SrcOver.derive(lineAlphaFLine) : null,
1338                                    new BasicStroke(lineWidthF, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND),
1339                                    AlphaComposite.SrcOver.derive(lineAlphaBLine),
1340                                    new BasicStroke(lineWidthB, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
1341            }
1342
1343            // remember draw parameter
1344            heatMapMapViewState = mapViewState;
1345            heatMapCacheLineWith = globalLineWidth;
1346            gpxLayerInvalidated = false;
1347        }
1348
1349        // 4th. Draw data on target layer, map data via color lookup table --------------
1350        drawHeatMapGrayMap(g, heatMapImgGray, lineWidthB > 2 ? (int) (lineWidthB*1.25f) : 1, lineWidth > 2 ? (lineWidth - 2) : 1);
1351    }
1352
1353    /**
1354     * Draw a dotted heat map
1355     *
1356     * @param gB              the common draw object to use
1357     * @param mv              the meta data to current displayed area
1358     * @param listSegm        segments visible in the current scope of mv
1359     * @param drawSize        draw size of draw element
1360     */
1361    private static void drawHeatGrayDotMap(Graphics2D gB, MapView mv, List<WayPoint> listSegm, int drawSize) {
1362
1363        // typical rendering rate -> use realtime preview instead of accurate display
1364        final double maxSegm = 25_000, nrSegms = listSegm.size();
1365
1366        // determine random drop rate
1367        final double randomDrop = Math.min(nrSegms > maxSegm ? (nrSegms - maxSegm) / nrSegms : 0, 0.70f);
1368
1369        // http://www.nstb.tc.faa.gov/reports/PAN94_0716.pdf#page=22
1370        // Global Average Position Domain Accuracy, typical -> not worst case !
1371        // < 4.218 m Vertical
1372        // < 2.168 m Horizontal
1373        final double pixelRmsX = (100 / mv.getDist100Pixel()) * 2.168;
1374        final double pixelRmsY = (100 / mv.getDist100Pixel()) * 4.218;
1375
1376        Point lastPnt = null;
1377
1378        // for all points, draw single lines
1379        for (WayPoint trkPnt : listSegm) {
1380
1381            // get transformed coordinates
1382            final Point paintPnt = mv.getPoint(trkPnt);
1383
1384            // end of line segment or end of list reached
1385            if (trkPnt.drawLine && null != lastPnt) {
1386                drawHeatSurfaceLine(gB, paintPnt, lastPnt, drawSize, pixelRmsX, pixelRmsY, randomDrop);
1387            }
1388
1389            // remember
1390            lastPnt = paintPnt;
1391        }
1392    }
1393
1394    /**
1395     * Draw a dotted surface line
1396     *
1397     * @param g                 the common draw object to use
1398     * @param fromPnt           start point
1399     * @param toPnt             end point
1400     * @param drawSize          size of draw elements
1401     * @param rmsSizeX          RMS size of circle for X (width)
1402     * @param rmsSizeY          RMS size of circle for Y (height)
1403     * @param dropRate          Pixel render drop rate
1404     */
1405    private static void drawHeatSurfaceLine(Graphics2D g,
1406            Point fromPnt, Point toPnt, int drawSize, double rmsSizeX, double rmsSizeY, double dropRate) {
1407
1408        // collect frequently used items
1409        final long fromX = (long) fromPnt.getX(); final long deltaX = (long) (toPnt.getX() - fromX);
1410        final long fromY = (long) fromPnt.getY(); final long deltaY = (long) (toPnt.getY() - fromY);
1411
1412        // use same random values for each point
1413        final Random heatMapRandom = new Random(fromX+fromY+deltaX+deltaY);
1414
1415        // cache distance between start and end point
1416        final int dist = (int) Math.abs(fromPnt.distance(toPnt));
1417
1418        // number of increment ( fill wide distance tracks )
1419        double scaleStep = Math.max(1.0f / dist, dist > 100 ? 0.10f : 0.20f);
1420
1421        // number of additional random points
1422        int rounds = Math.min(drawSize/2, 1)+1;
1423
1424        // decrease random noise at high drop rate ( more accurate draw of fewer points )
1425        rmsSizeX *= (1.0d - dropRate);
1426        rmsSizeY *= (1.0d - dropRate);
1427
1428        double scaleVal = 0;
1429
1430        // interpolate line draw ( needs separate point instead of line )
1431        while (scaleVal < (1.0d-0.0001d)) {
1432
1433            // get position
1434            final double pntX = fromX + scaleVal * deltaX;
1435            final double pntY = fromY + scaleVal * deltaY;
1436
1437            // add random distribution around sampled point
1438            for (int k = 0; k < rounds; k++) {
1439
1440                // add error distribution, first point with less error
1441                int x = (int) (pntX + heatMapRandom.nextGaussian() * (k > 0 ? rmsSizeX : rmsSizeX/4));
1442                int y = (int) (pntY + heatMapRandom.nextGaussian() * (k > 0 ? rmsSizeY : rmsSizeY/4));
1443
1444                // draw it, even drop is requested
1445                if (heatMapRandom.nextDouble() >= dropRate) {
1446                    g.fillRect(x-drawSize, y-drawSize, drawSize, drawSize);
1447                }
1448            }
1449            scaleVal += scaleStep;
1450        }
1451    }
1452
1453    /**
1454     * Apply default color configuration to way segments
1455     * @param visibleSegments segments visible in the current scope of mv
1456     */
1457    private void fixColors(List<WayPoint> visibleSegments) {
1458        for (WayPoint trkPnt : visibleSegments) {
1459            if (trkPnt.customColoring == null) {
1460                trkPnt.customColoring = neutralColor;
1461            }
1462        }
1463    }
1464
1465    /**
1466     * Check cache validity set necessary flags
1467     */
1468    private void checkCache() {
1469        // CHECKSTYLE.OFF: BooleanExpressionComplexity
1470        if ((computeCacheMaxLineLengthUsed != maxLineLength)
1471                || (computeCacheColored != colored)
1472                || (computeCacheVelocityTune != velocityTune)
1473                || (computeCacheColorDynamic != colorModeDynamic)
1474                || (computeCacheHeatMapDrawColorTableIdx != heatMapDrawColorTableIdx)
1475                || !Objects.equals(neutralColor, computeCacheColorUsed)
1476                || (computeCacheHeatMapDrawPointMode != heatMapDrawPointMode)
1477                || (computeCacheHeatMapDrawGain != heatMapDrawGain)
1478                || (computeCacheHeatMapDrawLowerLimit != heatMapDrawLowerLimit)
1479        ) {
1480            // CHECKSTYLE.ON: BooleanExpressionComplexity
1481            computeCacheMaxLineLengthUsed = maxLineLength;
1482            computeCacheInSync = false;
1483            computeCacheColorUsed = neutralColor;
1484            computeCacheColored = colored;
1485            computeCacheVelocityTune = velocityTune;
1486            computeCacheColorDynamic = colorModeDynamic;
1487            computeCacheHeatMapDrawColorTableIdx = heatMapDrawColorTableIdx;
1488            computeCacheHeatMapDrawPointMode = heatMapDrawPointMode;
1489            computeCacheHeatMapDrawGain = heatMapDrawGain;
1490            computeCacheHeatMapDrawLowerLimit = heatMapDrawLowerLimit;
1491        }
1492    }
1493
1494    /**
1495     *  callback when data is changed, invalidate cached configuration parameters
1496     */
1497    @Override
1498    public void gpxDataChanged(GpxDataChangeEvent e) {
1499        computeCacheInSync = false;
1500    }
1501
1502    /**
1503     * Draw all GPX arrays
1504     * @param g               the common draw object to use
1505     * @param mv              the meta data to current displayed area
1506     */
1507    public void drawColorBar(Graphics2D g, MapView mv) {
1508        int w = mv.getWidth();
1509
1510        // set do default
1511        g.setComposite(AlphaComposite.SrcOver.derive(1.00f));
1512
1513        if (colored == ColorMode.HDOP) {
1514            hdopScale.drawColorBar(g, w-30, 50, 20, 100, 1.0);
1515        } else if (colored == ColorMode.QUALITY) {
1516            qualityScale.drawColorBar(g, w-30, 50, 20, 100, 1.0);
1517        } else if (colored == ColorMode.VELOCITY) {
1518            SystemOfMeasurement som = SystemOfMeasurement.getSystemOfMeasurement();
1519            velocityScale.drawColorBar(g, w-30, 50, 20, 100, som.speedValue);
1520        } else if (colored == ColorMode.DIRECTION) {
1521            directionScale.drawColorBar(g, w-30, 50, 20, 100, 180.0/Math.PI);
1522        }
1523    }
1524
1525    @Override
1526    public void paintableInvalidated(PaintableInvalidationEvent event) {
1527        gpxLayerInvalidated = true;
1528    }
1529
1530    @Override
1531    public void detachFromMapView(MapViewEvent event) {
1532        SystemOfMeasurement.removeSoMChangeListener(this);
1533        layer.removeInvalidationListener(this);
1534        data.removeChangeListener(this);
1535    }
1536}