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

   1 package tim.prune.function.srtm;
   2
   3 import java.io.File;
   4 import java.io.FileInputStream;
   5 import java.io.IOException;
   6 import java.net.URL;
   7 import java.util.ArrayList;
   8 import java.util.zip.ZipEntry;
   9 import java.util.zip.ZipInputStream;
  10
  11 import javax.swing.JOptionPane;
  12
  13 import tim.prune.App;
  14 import tim.prune.DataSubscriber;
  15 import tim.prune.GenericFunction;
  16 import tim.prune.I18nManager;
  17 import tim.prune.UpdateMessageBroker;
  18 import tim.prune.config.Config;
  19 import tim.prune.data.Altitude;
  20 import tim.prune.data.DataPoint;
  21 import tim.prune.data.Field;
  22 import tim.prune.data.Track;
  23 import tim.prune.data.UnitSetLibrary;
  24 import tim.prune.gui.ProgressDialog;
  25 import tim.prune.tips.TipManager;
  26 import tim.prune.undo.UndoLookupSrtm;
  27
  28 /**
  29  * Class to provide a lookup function for point altitudes using the Space
  30  * Shuttle's SRTM data files. HGT files are downloaded into memory via HTTP and
  31  * point altitudes can then be interpolated from the 3m grid data.
  32  */
  33 public class LookupSrtmFunction extends GenericFunction implements Runnable
  34 {
  35         /** Progress dialog */
  36         private ProgressDialog _progress = null;
  37         /** Track to process */
  38         private Track _track = null;
  39         /** Flag for whether this is a real track or a terrain one */
  40         private boolean _normalTrack = true;
  41         /** Flag set when any tiles had to be downloaded (rather than just loaded locally) */
  42         private boolean _hadToDownload = false;
  43         /** Flag to check whether this function is currently running or not */
  44         private boolean _running = false;
  45
  46         /** Expected size of hgt file in bytes */
  47         private static final int HGT_ROW = 3601;
  48         private static final int HGT_SIZE = 2 * HGT_ROW * HGT_ROW;
  49         /** Altitude below which is considered void */
  50         private static final int VOID_VAL = -32768;
  51
  52         /**
  53          * Constructor
  54          * @param inApp  App object
  55          */
  56         public LookupSrtmFunction(App inApp) {
  57                 super(inApp);
  58         }
  59
  60         /** @return name key */
  61         public String getNameKey() {
  62                 return "function.lookupsrtm";
  63         }
  64
  65         /**
  66          * Begin the lookup using the normal track
  67          */
  68         public void begin() {
  69                 begin(_app.getTrackInfo().getTrack(), true);
  70         }
  71
  72         /**
  73          * Begin the lookup with an alternative track
  74          * @param inAlternativeTrack
  75          */
  76         public void begin(Track inAlternativeTrack) {
  77                 begin(inAlternativeTrack, false);
  78         }
  79
  80         /**
  81          * Begin the function with the given parameters
  82          * @param inTrack track to process
  83          * @param inNormalTrack true if this is a "normal" track, false for an artificially constructed one such as for terrain
  84          */
  85         private void begin(Track inTrack, boolean inNormalTrack)
  86         {
  87                 _running = true;
  88                 _hadToDownload = false;
  89                 if (_progress == null) {
  90                         _progress = new ProgressDialog(_parentFrame, getNameKey());
  91                 }
  92                 _progress.show();
  93                 _track = inTrack;
  94                 _normalTrack = inNormalTrack;
  95                 // start new thread for time-consuming part
  96                 new Thread(this).start();
  97         }
  98
  99         /**
 100          * Run method using separate thread
 101          */
 102         public void run()
 103         {
 104                 // Compile list of tiles to get
 105                 ArrayList<SrtmTile> tileList = new ArrayList<SrtmTile>();
 106                 boolean hasZeroAltitudePoints = false;
 107                 boolean hasNonZeroAltitudePoints = false;
 108                 // First, loop to see what kind of points we have
 109                 for (int i = 0; i < _track.getNumPoints(); i++)
 110                 {
 111                         if (_track.getPoint(i).hasAltitude())
 112                         {
 113                                 if (_track.getPoint(i).getAltitude().getValue() == 0) {
 114                                         hasZeroAltitudePoints = true;
 115                                 }
 116                                 else {
 117                                         hasNonZeroAltitudePoints = true;
 118                                 }
 119                         }
 120                 }
 121                 // Should we overwrite the zero altitude values?
 122                 boolean overwriteZeros = hasZeroAltitudePoints && !hasNonZeroAltitudePoints;
 123                 // If non-zero values present as well, ask user whether to overwrite the zeros or not
 124                 if (hasNonZeroAltitudePoints && hasZeroAltitudePoints && JOptionPane.showConfirmDialog(_parentFrame,
 125                         I18nManager.getText("dialog.lookupsrtm.overwritezeros"), I18nManager.getText(getNameKey()),
 126                         JOptionPane.YES_NO_OPTION) == JOptionPane.YES_OPTION)
 127                 {
 128                         overwriteZeros = true;
 129                 }
 130
 131                 // Now loop again to extract the required tiles
 132                 for (int i = 0; i < _track.getNumPoints(); i++)
 133                 {
 134                         // Consider points which don't have altitudes or have zero values
 135                         if (!_track.getPoint(i).hasAltitude()
 136                                 || (overwriteZeros && _track.getPoint(i).getAltitude().getValue() == 0))
 137                         {
 138                                 SrtmTile tile = new SrtmTile(_track.getPoint(i));
 139                                 boolean alreadyGot = false;
 140                                 for (int t = 0; t < tileList.size(); t++)
 141                                 {
 142                                         if (tileList.get(t).equals(tile)) {
 143                                                 alreadyGot = true;
 144                                         }
 145                                 }
 146                                 if (!alreadyGot) {tileList.add(tile);}
 147                         }
 148                 }
 149                 lookupValues(tileList, overwriteZeros);
 150                 // Finished
 151                 _running = false;
 152                 // Show tip if lots of online lookups were necessary
 153                 if (_hadToDownload) {
 154                         _app.showTip(TipManager.Tip_DownloadSrtm);
 155                 }
 156         }
 157
 158
 159         /**
 160          * Lookup the values from SRTM data
 161          * @param inTileList list of tiles to get
 162          * @param inOverwriteZeros true to overwrite zero altitude values
 163          */
 164         private void lookupValues(ArrayList<SrtmTile> inTileList, boolean inOverwriteZeros)
 165         {
 166                 UndoLookupSrtm undo = new UndoLookupSrtm(_app.getTrackInfo());
 167                 int numAltitudesFound = 0;
 168                 // Update progress bar
 169                 if (_progress != null)
 170                 {
 171                         _progress.setMaximum(inTileList.size());
 172                         _progress.setValue(0);
 173                 }
 174                 String errorMessage = null;
 175                 // Get urls for each tile
 176                 URL[] urls = TileFinder.getUrls(inTileList);
 177                 for (int t=0; t<inTileList.size() && !_progress.isCancelled(); t++)
 178                 {
 179                         if (urls[t] != null)
 180                         {
 181                                 SrtmTile tile = inTileList.get(t);
 182                                 try
 183                                 {
 184                                         // Set progress
 185                                         _progress.setValue(t);
 186                                         final int ARRLENGTH = HGT_ROW * HGT_ROW;
 187                                         int[] heights = new int[ARRLENGTH];
 188                                         // Open zipinputstream on url and check size
 189                                         ZipInputStream inStream = getStreamToHgtFile(urls[t]);
 190                                         boolean entryOk = false;
 191                                         if (inStream != null)
 192                                         {
 193                                                 ZipEntry entry = inStream.getNextEntry();
 194                                                 entryOk = (entry != null && entry.getSize() == HGT_SIZE);
 195                                                 if (entryOk)
 196                                                 {
 197                                                         // Read entire file contents into one byte array
 198                                                         for (int i = 0; i < ARRLENGTH; i++)
 199                                                         {
 200                                                                 heights[i] = inStream.read() * 256 + inStream.read();
 201                                                                 if (heights[i] >= 32768) {heights[i] -= 65536;}
 202                                                         }
 203                                                 }
 204                                                 // else {
 205                                                 //      System.out.println("length not ok: " + entry.getSize());
 206                                                 // }
 207                                                 // Close stream from url
 208                                                 inStream.close();
 209                                         }
 210
 211                                         if (entryOk)
 212                                         {
 213                                                 // Loop over all points in track, try to apply altitude from array
 214                                                 for (int p = 0; p < _track.getNumPoints(); p++)
 215                                                 {
 216                                                         DataPoint point = _track.getPoint(p);
 217                                                         if (!point.hasAltitude()
 218                                                                 || (inOverwriteZeros && point.getAltitude().getValue() == 0))
 219                                                         {
 220                                                                 if (new SrtmTile(point).equals(tile))
 221                                                                 {
 222                                                                         double x = (point.getLongitude().getDouble() - tile.getLongitude()) * (HGT_ROW - 1);
 223                                                                         double y = HGT_ROW - (point.getLatitude().getDouble() - tile.getLatitude()) * (HGT_ROW - 1);
 224                                                                         int idx1 = ((int)y)*HGT_ROW + (int)x;
 225                                                                         try
 226                                                                         {
 227                                                                                 int[] fouralts = {heights[idx1], heights[idx1+1], heights[idx1-HGT_ROW], heights[idx1-HGT_ROW+1]};
 228                                                                                 int numVoids = (fouralts[0]==VOID_VAL?1:0) + (fouralts[1]==VOID_VAL?1:0)
 229                                                                                         + (fouralts[2]==VOID_VAL?1:0) + (fouralts[3]==VOID_VAL?1:0);
 230                                                                                 // if (numVoids > 0) System.out.println(numVoids + " voids found");
 231                                                                                 double altitude = 0.0;
 232                                                                                 switch (numVoids)
 233                                                                                 {
 234                                                                                         case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
 235                                                                                         case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
 236                                                                                         case 2:
 237                                                                                         case 3: altitude = averageNonVoid(fouralts); break;
 238                                                                                         default: altitude = VOID_VAL;
 239                                                                                 }
 240                                                                                 // Special case for terrain tracks, don't interpolate voids yet
 241                                                                                 if (!_normalTrack && numVoids > 0) {
 242                                                                                         altitude = VOID_VAL;
 243                                                                                 }
 244                                                                                 if (altitude != VOID_VAL)
 245                                                                                 {
 246                                                                                         point.setFieldValue(Field.ALTITUDE, ""+altitude, false);
 247                                                                                         // depending on settings, this value may have been added as feet, we need to force metres
 248                                                                                         point.getAltitude().reset(new Altitude((int)altitude, UnitSetLibrary.UNITS_METRES));
 249                                                                                         numAltitudesFound++;
 250                                                                                 }
 251                                                                         }
 252                                                                         catch (ArrayIndexOutOfBoundsException obe) {
 253                                                                                 // System.err.println("lat=" + point.getLatitude().getDouble() + ", x=" + x + ", y=" + y + ", idx=" + idx1);
 254                                                                         }
 255                                                                 }
 256                                                         }
 257                                                 }
 258                                         }
 259                                 }
 260                                 catch (IOException ioe) {errorMessage = ioe.getClass().getName() + " - " + ioe.getMessage();
 261                                 }
 262                         }
 263                 }
 264
 265                 _progress.dispose();
 266                 if (_progress.isCancelled()) {
 267                         return;
 268                 }
 269
 270                 if (numAltitudesFound > 0)
 271                 {
 272                         // Inform app including undo information
 273                         _track.requestRescale();
 274                         UpdateMessageBroker.informSubscribers(DataSubscriber.DATA_ADDED_OR_REMOVED);
 275                         // Don't update app if we're doing another track
 276                         if (_normalTrack)
 277                         {
 278                                 _app.completeFunction(undo,
 279                                         I18nManager.getTextWithNumber("confirm.lookupsrtm", numAltitudesFound));
 280                         }
 281                 }
 282                 else if (errorMessage != null) {
 283                         _app.showErrorMessageNoLookup(getNameKey(), errorMessage);
 284                 }
 285                 else if (inTileList.size() > 0) {
 286                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonefound");
 287                 }
 288                 else {
 289                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonerequired");
 290                 }
 291         }
 292
 293         /**
 294          * See whether the SRTM file is already available locally first, then try online
 295          * @param inUrl URL for online resource
 296          * @return ZipInputStream either on the local file or on the downloaded zip file
 297          */
 298         private ZipInputStream getStreamToHgtFile(URL inUrl)
 299         throws IOException
 300         {
 301                 String diskCachePath = Config.getConfigString(Config.KEY_DISK_CACHE);
 302                 if (diskCachePath != null)
 303                 {
 304                         File srtmDir = new File(diskCachePath, "srtm");
 305                         if (srtmDir.exists() && srtmDir.isDirectory() && srtmDir.canRead())
 306                         {
 307                                 File srtmFile = new File(srtmDir, new File(inUrl.getFile()).getName());
 308                                 if (srtmFile.exists() && srtmFile.isFile() && srtmFile.canRead()
 309                                         && srtmFile.length() > 400)
 310                                 {
 311                                         // System.out.println("Lookup: Using file " + srtmFile.getAbsolutePath());
 312                                         // File found, use this one
 313                                         return new ZipInputStream(new FileInputStream(srtmFile));
 314                                 }
 315                         }
 316                 }
 317                 // System.out.println("Lookup: Trying online: " + inUrl.toString());
 318                 _hadToDownload = true;
 319                 // MAYBE: Only download if we're in online mode?
 320                 // return new ZipInputStream(inUrl.openStream());
 321                 return null;
 322         }
 323
 324         /**
 325          * Perform a bilinear interpolation on the given altitude array
 326          * @param inAltitudes array of four altitude values on corners of square (bl, br, tl, tr)
 327          * @param inX x coordinate
 328          * @param inY y coordinate
 329          * @return interpolated altitude
 330          */
 331         private static double bilinearInterpolate(int[] inAltitudes, double inX, double inY)
 332         {
 333                 double alpha = inX - (int) inX;
 334                 double beta  = 1 - (inY - (int) inY);
 335                 double alt = (1-alpha)*(1-beta)*inAltitudes[0] + alpha*(1-beta)*inAltitudes[1]
 336                         + (1-alpha)*beta*inAltitudes[2] + alpha*beta*inAltitudes[3];
 337                 return alt;
 338         }
 339
 340         /**
 341          * Fix a single void in the given array by replacing it with the average of the others
 342          * @param inAltitudes array of altitudes containing one void
 343          * @return fixed array without voids
 344          */
 345         private static int[] fixVoid(int[] inAltitudes)
 346         {
 347                 int[] fixed = new int[inAltitudes.length];
 348                 for (int i = 0; i < inAltitudes.length; i++)
 349                 {
 350                         if (inAltitudes[i] == VOID_VAL) {
 351                                 fixed[i] = (int) Math.round(averageNonVoid(inAltitudes));
 352                         }
 353                         else {
 354                                 fixed[i] = inAltitudes[i];
 355                         }
 356                 }
 357                 return fixed;
 358         }
 359
 360         /**
 361          * Calculate the average of the non-void altitudes in the given array
 362          * @param inAltitudes array of altitudes with one or more voids
 363          * @return average of non-void altitudes
 364          */
 365         private static final double averageNonVoid(int[] inAltitudes)
 366         {
 367                 double totalAltitude = 0.0;
 368                 int numAlts = 0;
 369                 for (int i = 0; i < inAltitudes.length; i++)
 370                 {
 371                         if (inAltitudes[i] != VOID_VAL)
 372                         {
 373                                 totalAltitude += inAltitudes[i];
 374                                 numAlts++;
 375                         }
 376                 }
 377                 if (numAlts < 1) {return VOID_VAL;}
 378                 return totalAltitude / numAlts;
 379         }
 380
 381         /**
 382          * @return true if a thread is currently running
 383          */
 384         public boolean isRunning()
 385         {
 386                 return _running;
 387         }
 388 }