src/tim/prune/function/srtm/LookupSrtmFunction.java

   1 package tim.prune.function.srtm;
   2
   3 import java.util.ArrayList;
   4
   5 import javax.swing.JOptionPane;
   6
   7 import tim.prune.App;
   8 import tim.prune.DataSubscriber;
   9 import tim.prune.GenericFunction;
  10 import tim.prune.I18nManager;
  11 import tim.prune.UpdateMessageBroker;
  12 import tim.prune.data.Altitude;
  13 import tim.prune.data.DataPoint;
  14 import tim.prune.data.Field;
  15 import tim.prune.data.Track;
  16 import tim.prune.data.UnitSetLibrary;
  17 import tim.prune.gui.ProgressDialog;
  18 import tim.prune.undo.UndoLookupSrtm;
  19
  20 /**
  21  * Class to provide a lookup function for point altitudes using the Space
  22  * Shuttle's SRTM data files. HGT files are downloaded into memory via HTTP and
  23  * point altitudes can then be interpolated from the 3m grid data.
  24  */
  25 public class LookupSrtmFunction extends GenericFunction implements Runnable
  26 {
  27         /** Progress dialog */
  28         private ProgressDialog _progress = null;
  29         /** Track to process */
  30         private Track _track = null;
  31         /** Flag for whether this is a real track or a terrain one */
  32         private boolean _normalTrack = true;
  33         /** Flag to check whether this function is currently running or not */
  34         private boolean _running = false;
  35
  36         /** Altitude below which is considered void */
  37         private static final int VOID_VAL = -32768;
  38
  39         /**
  40          * Constructor
  41          * @param inApp  App object
  42          */
  43         public LookupSrtmFunction(App inApp) {
  44                 super(inApp);
  45         }
  46
  47         /** @return name key */
  48         public String getNameKey() {
  49                 return "function.lookupsrtm";
  50         }
  51
  52         /**
  53          * Begin the lookup using the normal track
  54          */
  55         public void begin() {
  56                 begin(_app.getTrackInfo().getTrack(), true);
  57         }
  58
  59         /**
  60          * Begin the lookup with an alternative track
  61          * @param inAlternativeTrack
  62          */
  63         public void begin(Track inAlternativeTrack) {
  64                 begin(inAlternativeTrack, false);
  65         }
  66
  67         /**
  68          * Begin the function with the given parameters
  69          * @param inTrack track to process
  70          * @param inNormalTrack true if this is a "normal" track, false for an artificially constructed one such as for terrain
  71          */
  72         private void begin(Track inTrack, boolean inNormalTrack)
  73         {
  74                 _running = true;
  75                 if (! SrtmDiskCache.ensureCacheIsUsable())
  76                 {
  77                         _app.showErrorMessage(getNameKey(), "error.cache.notthere");
  78                 }
  79                 if (_progress == null) {
  80                         _progress = new ProgressDialog(_parentFrame, getNameKey());
  81                 }
  82                 _progress.show();
  83                 _track = inTrack;
  84                 _normalTrack = inNormalTrack;
  85                 // start new thread for time-consuming part
  86                 new Thread(this).start();
  87         }
  88
  89         /**
  90          * Run method using separate thread
  91          */
  92         public void run()
  93         {
  94                 // Compile list of tiles to get
  95                 ArrayList<SrtmTile> tileList = new ArrayList<SrtmTile>();
  96
  97                 // Now loop again to extract the required tiles
  98                 for (int i = 0; i < _track.getNumPoints(); i++)
  99                 {
 100                         SrtmTile tile = new SrtmTile(_track.getPoint(i));
 101                         boolean alreadyGot = false;
 102                         for (int t = 0; t < tileList.size(); t++)
 103                         {
 104                                 if (tileList.get(t).equals(tile)) {
 105                                         alreadyGot = true;
 106                                 }
 107                         }
 108                         if (!alreadyGot) {tileList.add(tile);}
 109                 }
 110                 lookupValues(tileList);
 111                 // Finished
 112                 _running = false;
 113         }
 114
 115         /**
 116          * Lookup the values from SRTM data
 117          * @param inTileList list of tiles to get
 118          * @param inOverwriteZeros true to overwrite zero altitude values
 119          */
 120         private void lookupValues(ArrayList<SrtmTile> inTileList)
 121         {
 122                 UndoLookupSrtm undo = new UndoLookupSrtm(_app.getTrackInfo());
 123                 int numAltitudesFound = 0;
 124                 // Update progress bar
 125                 if (_progress != null)
 126                 {
 127                         _progress.setMaximum(inTileList.size());
 128                         _progress.setValue(0);
 129                 }
 130                 String errorMessage = "";
 131                 for (int t=0; t<inTileList.size() && !_progress.isCancelled(); t++)
 132                 {
 133                         SrtmTile tile = inTileList.get(t);
 134                         SrtmSource srtmSource = tile.findBestCachedSource();
 135
 136                         if (srtmSource == null)
 137                         {
 138                                 errorMessage += "Tile "+tile.getTileName()+" not in cache!\n";
 139                                 continue;
 140                         }
 141
 142                         // Set progress
 143                         _progress.setValue(t);
 144
 145                         int[] heights;
 146                         try {
 147                                 heights = srtmSource.getTileHeights(tile);
 148                         }
 149                         catch (SrtmSourceException e)
 150                         {
 151                                 errorMessage += e.getMessage();
 152                                 e.printStackTrace();
 153                                 continue;
 154                         }
 155                         int rowSize = srtmSource.getRowSize(tile);
 156                         if (rowSize <= 0)
 157                         {
 158                                 errorMessage += "Tile "+tile.getTileName()+" is corrupted";
 159                         }
 160
 161                         numAltitudesFound += applySrtmTimeToWholeTrack(tile, heights, rowSize);
 162                 }
 163
 164                 _progress.dispose();
 165                 if (_progress.isCancelled()) {
 166                         return;
 167                 }
 168
 169                 if (! errorMessage.equals("")) {
 170                         _app.showErrorMessageNoLookup(getNameKey(), errorMessage);
 171                         return;
 172                 }
 173                 if (numAltitudesFound > 0)
 174                 {
 175                         // Inform app including undo information
 176                         _track.requestRescale();
 177                         UpdateMessageBroker.informSubscribers(DataSubscriber.DATA_ADDED_OR_REMOVED);
 178                         // Don't update app if we're doing another track
 179                         if (_normalTrack)
 180                         {
 181                                 _app.completeFunction(undo,
 182                                         I18nManager.getTextWithNumber("confirm.lookupsrtm", numAltitudesFound));
 183                         }
 184                 }
 185                 else if (inTileList.size() > 0) {
 186                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonefound");
 187                 }
 188                 else {
 189                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonerequired");
 190                 }
 191         }
 192
 193         /**
 194          * Given the height data read in from file, apply the given tile to all points
 195          * in the track with missing altitude
 196          * @param inTile tile being applied
 197          * @param inHeights height data read in from file
 198          * @return number of altitudes found
 199          */
 200         private int applySrtmTimeToWholeTrack(SrtmTile inTile, int[] inHeights, int inRowSize)
 201         {
 202                 int numAltitudesFound = 0;
 203                 // Loop over all points in track, try to apply altitude from array
 204                 for (int p = 0; p < _track.getNumPoints(); p++)
 205                 {
 206                         DataPoint point = _track.getPoint(p);
 207                         if (new SrtmTile(point).equals(inTile))
 208                         {
 209                                 double x = (point.getLongitude().getDouble() - inTile.getLongitude()) * (inRowSize - 1);
 210                                 double y = inRowSize - (point.getLatitude().getDouble() - inTile.getLatitude()) * (inRowSize - 1);
 211                                 int idx1 = ((int)y)*inRowSize + (int)x;
 212                                 try
 213                                 {
 214                                         int[] fouralts = {inHeights[idx1], inHeights[idx1+1], inHeights[idx1-inRowSize], inHeights[idx1-inRowSize+1]};
 215                                         int numVoids = (fouralts[0]==VOID_VAL?1:0) + (fouralts[1]==VOID_VAL?1:0)
 216                                                 + (fouralts[2]==VOID_VAL?1:0) + (fouralts[3]==VOID_VAL?1:0);
 217                                         // if (numVoids > 0) System.out.println(numVoids + " voids found");
 218                                         double altitude = 0.0;
 219                                         switch (numVoids)
 220                                         {
 221                                         case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
 222                                         case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
 223                                         case 2:
 224                                         case 3: altitude = averageNonVoid(fouralts); break;
 225                                         default: altitude = VOID_VAL;
 226                                         }
 227                                         // Special case for terrain tracks, don't interpolate voids yet
 228                                         if (!_normalTrack && numVoids > 0) {
 229                                                 altitude = VOID_VAL;
 230                                         }
 231                                         if (altitude != VOID_VAL)
 232                                         {
 233                                                 point.setFieldValue(Field.ALTITUDE, ""+altitude, false);
 234                                                 // depending on settings, this value may have been added as feet, we need to force metres
 235                                                 point.getAltitude().reset(new Altitude((int)altitude, UnitSetLibrary.UNITS_METRES));
 236                                                 numAltitudesFound++;
 237                                         }
 238                                 }
 239                                 catch (ArrayIndexOutOfBoundsException obe) {
 240                                         System.err.println("Point not in tile? lat=" + point.getLatitude().getDouble() + ", x=" + x + ", y=" + y + ", idx=" + idx1+"\n");
 241                                 }
 242                         }
 243                 }
 244                 return numAltitudesFound;
 245         }
 246
 247         /**
 248          * Perform a bilinear interpolation on the given altitude array
 249          * @param inAltitudes array of four altitude values on corners of square (bl, br, tl, tr)
 250          * @param inX x coordinate
 251          * @param inY y coordinate
 252          * @return interpolated altitude
 253          */
 254         private static double bilinearInterpolate(int[] inAltitudes, double inX, double inY)
 255         {
 256                 double alpha = inX - (int) inX;
 257                 double beta  = 1 - (inY - (int) inY);
 258                 double alt = (1-alpha)*(1-beta)*inAltitudes[0] + alpha*(1-beta)*inAltitudes[1]
 259                         + (1-alpha)*beta*inAltitudes[2] + alpha*beta*inAltitudes[3];
 260                 return alt;
 261         }
 262
 263         /**
 264          * Fix a single void in the given array by replacing it with the average of the others
 265          * @param inAltitudes array of altitudes containing one void
 266          * @return fixed array without voids
 267          */
 268         private static int[] fixVoid(int[] inAltitudes)
 269         {
 270                 int[] fixed = new int[inAltitudes.length];
 271                 for (int i = 0; i < inAltitudes.length; i++)
 272                 {
 273                         if (inAltitudes[i] == VOID_VAL) {
 274                                 fixed[i] = (int) Math.round(averageNonVoid(inAltitudes));
 275                         }
 276                         else {
 277                                 fixed[i] = inAltitudes[i];
 278                         }
 279                 }
 280                 return fixed;
 281         }
 282
 283         /**
 284          * Calculate the average of the non-void altitudes in the given array
 285          * @param inAltitudes array of altitudes with one or more voids
 286          * @return average of non-void altitudes
 287          */
 288         private static final double averageNonVoid(int[] inAltitudes)
 289         {
 290                 double totalAltitude = 0.0;
 291                 int numAlts = 0;
 292                 for (int i = 0; i < inAltitudes.length; i++)
 293                 {
 294                         if (inAltitudes[i] != VOID_VAL)
 295                         {
 296                                 totalAltitude += inAltitudes[i];
 297                                 numAlts++;
 298                         }
 299                 }
 300                 if (numAlts < 1) {return VOID_VAL;}
 301                 return totalAltitude / numAlts;
 302         }
 303
 304         /**
 305          * @return true if a thread is currently running
 306          */
 307         public boolean isRunning()
 308         {
 309                 return _running;
 310         }
 311 }