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 long HGT_SIZE = 2884802L;
  48         /** Altitude below which is considered void */
  49         private static final int VOID_VAL = -32768;
  50
  51         /**
  52          * Constructor
  53          * @param inApp  App object
  54          */
  55         public LookupSrtmFunction(App inApp) {
  56                 super(inApp);
  57         }
  58
  59         /** @return name key */
  60         public String getNameKey() {
  61                 return "function.lookupsrtm";
  62         }
  63
  64         /**
  65          * Begin the lookup using the normal track
  66          */
  67         public void begin() {
  68                 begin(_app.getTrackInfo().getTrack(), true);
  69         }
  70
  71         /**
  72          * Begin the lookup with an alternative track
  73          * @param inAlternativeTrack
  74          */
  75         public void begin(Track inAlternativeTrack) {
  76                 begin(inAlternativeTrack, false);
  77         }
  78
  79         /**
  80          * Begin the function with the given parameters
  81          * @param inTrack track to process
  82          * @param inNormalTrack true if this is a "normal" track, false for an artificially constructed one such as for terrain
  83          */
  84         private void begin(Track inTrack, boolean inNormalTrack)
  85         {
  86                 _running = true;
  87                 _hadToDownload = false;
  88                 if (_progress == null) {
  89                         _progress = new ProgressDialog(_parentFrame, getNameKey());
  90                 }
  91                 _progress.show();
  92                 _track = inTrack;
  93                 _normalTrack = inNormalTrack;
  94                 // start new thread for time-consuming part
  95                 new Thread(this).start();
  96         }
  97
  98         /**
  99          * Run method using separate thread
 100          */
 101         public void run()
 102         {
 103                 // Compile list of tiles to get
 104                 ArrayList<SrtmTile> tileList = new ArrayList<SrtmTile>();
 105                 boolean hasZeroAltitudePoints = false;
 106                 boolean hasNonZeroAltitudePoints = false;
 107                 // First, loop to see what kind of points we have
 108                 for (int i = 0; i < _track.getNumPoints(); i++)
 109                 {
 110                         if (_track.getPoint(i).hasAltitude())
 111                         {
 112                                 if (_track.getPoint(i).getAltitude().getValue() == 0) {
 113                                         hasZeroAltitudePoints = true;
 114                                 }
 115                                 else {
 116                                         hasNonZeroAltitudePoints = true;
 117                                 }
 118                         }
 119                 }
 120                 // Should we overwrite the zero altitude values?
 121                 boolean overwriteZeros = hasZeroAltitudePoints && !hasNonZeroAltitudePoints;
 122                 // If non-zero values present as well, ask user whether to overwrite the zeros or not
 123                 if (hasNonZeroAltitudePoints && hasZeroAltitudePoints && JOptionPane.showConfirmDialog(_parentFrame,
 124                         I18nManager.getText("dialog.lookupsrtm.overwritezeros"), I18nManager.getText(getNameKey()),
 125                         JOptionPane.YES_NO_OPTION) == JOptionPane.YES_OPTION)
 126                 {
 127                         overwriteZeros = true;
 128                 }
 129
 130                 // Now loop again to extract the required tiles
 131                 for (int i = 0; i < _track.getNumPoints(); i++)
 132                 {
 133                         // Consider points which don't have altitudes or have zero values
 134                         if (!_track.getPoint(i).hasAltitude()
 135                                 || (overwriteZeros && _track.getPoint(i).getAltitude().getValue() == 0))
 136                         {
 137                                 SrtmTile tile = new SrtmTile(_track.getPoint(i));
 138                                 boolean alreadyGot = false;
 139                                 for (int t = 0; t < tileList.size(); t++)
 140                                 {
 141                                         if (tileList.get(t).equals(tile)) {
 142                                                 alreadyGot = true;
 143                                         }
 144                                 }
 145                                 if (!alreadyGot) {tileList.add(tile);}
 146                         }
 147                 }
 148                 lookupValues(tileList, overwriteZeros);
 149                 // Finished
 150                 _running = false;
 151                 // Show tip if lots of online lookups were necessary
 152                 if (_hadToDownload) {
 153                         _app.showTip(TipManager.Tip_DownloadSrtm);
 154                 }
 155         }
 156
 157
 158         /**
 159          * Lookup the values from SRTM data
 160          * @param inTileList list of tiles to get
 161          * @param inOverwriteZeros true to overwrite zero altitude values
 162          */
 163         private void lookupValues(ArrayList<SrtmTile> inTileList, boolean inOverwriteZeros)
 164         {
 165                 UndoLookupSrtm undo = new UndoLookupSrtm(_app.getTrackInfo());
 166                 int numAltitudesFound = 0;
 167                 // Update progress bar
 168                 if (_progress != null)
 169                 {
 170                         _progress.setMaximum(inTileList.size());
 171                         _progress.setValue(0);
 172                 }
 173                 String errorMessage = null;
 174                 // Get urls for each tile
 175                 URL[] urls = TileFinder.getUrls(inTileList);
 176                 for (int t=0; t<inTileList.size() && !_progress.isCancelled(); t++)
 177                 {
 178                         if (urls[t] != null)
 179                         {
 180                                 SrtmTile tile = inTileList.get(t);
 181                                 try
 182                                 {
 183                                         // Set progress
 184                                         _progress.setValue(t);
 185                                         final int ARRLENGTH = 1201 * 1201;
 186                                         int[] heights = new int[ARRLENGTH];
 187                                         // Open zipinputstream on url and check size
 188                                         ZipInputStream inStream = getStreamToHgtFile(urls[t]);
 189                                         boolean entryOk = false;
 190                                         if (inStream != null)
 191                                         {
 192                                                 ZipEntry entry = inStream.getNextEntry();
 193                                                 entryOk = (entry != null && entry.getSize() == HGT_SIZE);
 194                                                 if (entryOk)
 195                                                 {
 196                                                         // Read entire file contents into one byte array
 197                                                         for (int i = 0; i < ARRLENGTH; i++)
 198                                                         {
 199                                                                 heights[i] = inStream.read() * 256 + inStream.read();
 200                                                                 if (heights[i] >= 32768) {heights[i] -= 65536;}
 201                                                         }
 202                                                 }
 203                                                 // else {
 204                                                 //      System.out.println("length not ok: " + entry.getSize());
 205                                                 // }
 206                                                 // Close stream from url
 207                                                 inStream.close();
 208                                         }
 209
 210                                         if (entryOk)
 211                                         {
 212                                                 // Loop over all points in track, try to apply altitude from array
 213                                                 for (int p = 0; p < _track.getNumPoints(); p++)
 214                                                 {
 215                                                         DataPoint point = _track.getPoint(p);
 216                                                         if (!point.hasAltitude()
 217                                                                 || (inOverwriteZeros && point.getAltitude().getValue() == 0))
 218                                                         {
 219                                                                 if (new SrtmTile(point).equals(tile))
 220                                                                 {
 221                                                                         double x = (point.getLongitude().getDouble() - tile.getLongitude()) * 1200;
 222                                                                         double y = 1201 - (point.getLatitude().getDouble() - tile.getLatitude()) * 1200;
 223                                                                         int idx1 = ((int)y)*1201 + (int)x;
 224                                                                         try
 225                                                                         {
 226                                                                                 int[] fouralts = {heights[idx1], heights[idx1+1], heights[idx1-1201], heights[idx1-1200]};
 227                                                                                 int numVoids = (fouralts[0]==VOID_VAL?1:0) + (fouralts[1]==VOID_VAL?1:0)
 228                                                                                         + (fouralts[2]==VOID_VAL?1:0) + (fouralts[3]==VOID_VAL?1:0);
 229                                                                                 // if (numVoids > 0) System.out.println(numVoids + " voids found");
 230                                                                                 double altitude = 0.0;
 231                                                                                 switch (numVoids) {
 232                                                                                         case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
 233                                                                                         case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
 234                                                                                         case 2:
 235                                                                                         case 3: altitude = averageNonVoid(fouralts); break;
 236                                                                                         default: altitude = VOID_VAL;
 237                                                                                 }
 238                                                                                 if (altitude != VOID_VAL)
 239                                                                                 {
 240                                                                                         point.setFieldValue(Field.ALTITUDE, ""+altitude, false);
 241                                                                                         // depending on settings, this value may have been added as feet, we need to force metres
 242                                                                                         point.getAltitude().reset(new Altitude((int)altitude, UnitSetLibrary.UNITS_METRES));
 243                                                                                         numAltitudesFound++;
 244                                                                                 }
 245                                                                         }
 246                                                                         catch (ArrayIndexOutOfBoundsException obe) {
 247                                                                                 // System.err.println("lat=" + point.getLatitude().getDouble() + ", x=" + x + ", y=" + y + ", idx=" + idx1);
 248                                                                         }
 249                                                                 }
 250                                                         }
 251                                                 }
 252                                         }
 253                                 }
 254                                 catch (IOException ioe) {errorMessage = ioe.getClass().getName() + " - " + ioe.getMessage();
 255                                 }
 256                         }
 257                 }
 258
 259                 _progress.dispose();
 260                 if (_progress.isCancelled()) {
 261                         return;
 262                 }
 263
 264                 if (numAltitudesFound > 0)
 265                 {
 266                         // Inform app including undo information
 267                         _track.requestRescale();
 268                         UpdateMessageBroker.informSubscribers(DataSubscriber.DATA_ADDED_OR_REMOVED);
 269                         // Don't update app if we're doing another track
 270                         if (_normalTrack)
 271                         {
 272                                 _app.completeFunction(undo,
 273                                         I18nManager.getTextWithNumber("confirm.lookupsrtm", numAltitudesFound));
 274                         }
 275                 }
 276                 else if (errorMessage != null) {
 277                         _app.showErrorMessageNoLookup(getNameKey(), errorMessage);
 278                 }
 279                 else if (inTileList.size() > 0) {
 280                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonefound");
 281                 }
 282                 else {
 283                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonerequired");
 284                 }
 285         }
 286
 287         /**
 288          * See whether the SRTM file is already available locally first, then try online
 289          * @param inUrl URL for online resource
 290          * @return ZipInputStream either on the local file or on the downloaded zip file
 291          */
 292         private ZipInputStream getStreamToHgtFile(URL inUrl)
 293         throws IOException
 294         {
 295                 String diskCachePath = Config.getConfigString(Config.KEY_DISK_CACHE);
 296                 if (diskCachePath != null)
 297                 {
 298                         File srtmDir = new File(diskCachePath, "srtm");
 299                         if (srtmDir.exists() && srtmDir.isDirectory() && srtmDir.canRead())
 300                         {
 301                                 File srtmFile = new File(srtmDir, new File(inUrl.getFile()).getName());
 302                                 if (srtmFile.exists() && srtmFile.isFile() && srtmFile.canRead())
 303                                 {
 304                                         // System.out.println("Lookup: Using file " + srtmFile.getAbsolutePath());
 305                                         // File found, use this one
 306                                         return new ZipInputStream(new FileInputStream(srtmFile));
 307                                 }
 308                         }
 309                 }
 310                 // System.out.println("Lookup: Trying online: " + inUrl.toString());
 311                 _hadToDownload = true;
 312                 // MAYBE: Only download if we're in online mode?
 313                 return new ZipInputStream(inUrl.openStream());
 314         }
 315
 316         /**
 317          * Perform a bilinear interpolation on the given altitude array
 318          * @param inAltitudes array of four altitude values on corners of square (bl, br, tl, tr)
 319          * @param inX x coordinate
 320          * @param inY y coordinate
 321          * @return interpolated altitude
 322          */
 323         private static double bilinearInterpolate(int[] inAltitudes, double inX, double inY)
 324         {
 325                 double alpha = inX - (int) inX;
 326                 double beta  = 1 - (inY - (int) inY);
 327                 double alt = (1-alpha)*(1-beta)*inAltitudes[0] + alpha*(1-beta)*inAltitudes[1]
 328                         + (1-alpha)*beta*inAltitudes[2] + alpha*beta*inAltitudes[3];
 329                 return alt;
 330         }
 331
 332         /**
 333          * Fix a single void in the given array by replacing it with the average of the others
 334          * @param inAltitudes array of altitudes containing one void
 335          * @return fixed array without voids
 336          */
 337         private static int[] fixVoid(int[] inAltitudes)
 338         {
 339                 int[] fixed = new int[inAltitudes.length];
 340                 for (int i = 0; i < inAltitudes.length; i++)
 341                 {
 342                         if (inAltitudes[i] == VOID_VAL) {
 343                                 fixed[i] = (int) Math.round(averageNonVoid(inAltitudes));
 344                         }
 345                         else {
 346                                 fixed[i] = inAltitudes[i];
 347                         }
 348                 }
 349                 return fixed;
 350         }
 351
 352         /**
 353          * Calculate the average of the non-void altitudes in the given array
 354          * @param inAltitudes array of altitudes with one or more voids
 355          * @return average of non-void altitudes
 356          */
 357         private static final double averageNonVoid(int[] inAltitudes)
 358         {
 359                 double totalAltitude = 0.0;
 360                 int numAlts = 0;
 361                 for (int i = 0; i < inAltitudes.length; i++)
 362                 {
 363                         if (inAltitudes[i] != VOID_VAL)
 364                         {
 365                                 totalAltitude += inAltitudes[i];
 366                                 numAlts++;
 367                         }
 368                 }
 369                 if (numAlts < 1) {return VOID_VAL;}
 370                 return totalAltitude / numAlts;
 371         }
 372
 373         /**
 374          * @return true if a thread is currently running
 375          */
 376         public boolean isRunning()
 377         {
 378                 return _running;
 379         }
 380 }