1 package tim.prune.function.srtm;
4 import java.io.FileInputStream;
5 import java.io.IOException;
7 import java.util.HashSet;
8 import java.util.zip.ZipEntry;
9 import java.util.zip.ZipInputStream;
11 import javax.swing.JOptionPane;
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;
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.
33 public class LookupSrtmFunction extends GenericFunction implements Runnable
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 /** Count the number of tiles downloaded and cached */
44 private int _numCached = 0;
45 /** Flag to check whether this function is currently running or not */
46 private boolean _running = false;
48 /** Expected size of hgt file in bytes */
49 private static final long HGT_SIZE = 2884802L;
50 /** Altitude below which is considered void */
51 private static final int VOID_VAL = -32768;
55 * @param inApp App object
57 public LookupSrtmFunction(App inApp) {
61 /** @return name key */
62 public String getNameKey() {
63 return "function.lookupsrtm";
67 * Begin the lookup using the normal track
70 begin(_app.getTrackInfo().getTrack(), true);
74 * Begin the lookup with an alternative track
75 * @param inAlternativeTrack
77 public void begin(Track inAlternativeTrack) {
78 begin(inAlternativeTrack, false);
82 * Begin the function with the given parameters
83 * @param inTrack track to process
84 * @param inNormalTrack true if this is a "normal" track, false for an artificially constructed one such as for terrain
86 private void begin(Track inTrack, boolean inNormalTrack)
89 _hadToDownload = false;
90 if (_progress == null) {
91 _progress = new ProgressDialog(_parentFrame, getNameKey());
95 _normalTrack = inNormalTrack;
96 // start new thread for time-consuming part
97 new Thread(this).start();
101 * Run method using separate thread
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++)
110 if (_track.getPoint(i).hasAltitude())
112 if (_track.getPoint(i).getAltitude().getValue() == 0) {
113 hasZeroAltitudePoints = true;
116 hasNonZeroAltitudePoints = true;
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)
127 overwriteZeros = true;
130 // Now loop again to extract the required tiles
131 HashSet<SrtmTile> tileSet = new HashSet<SrtmTile>();
132 for (int i = 0; i < _track.getNumPoints(); i++)
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))
138 tileSet.add(new SrtmTile(_track.getPoint(i)));
141 lookupValues(tileSet, overwriteZeros);
144 // Show tip if lots of online lookups were necessary
145 if (_hadToDownload) {
146 _app.showTip(TipManager.Tip_DownloadSrtm);
148 else if (_numCached > 0) {
149 showConfirmMessage(_numCached);
155 * Lookup the values from SRTM data
156 * @param inTileSet set of tiles to get
157 * @param inOverwriteZeros true to overwrite zero altitude values
159 private void lookupValues(HashSet<SrtmTile> inTileSet, boolean inOverwriteZeros)
161 UndoLookupSrtm undo = new UndoLookupSrtm(_app.getTrackInfo());
162 int numAltitudesFound = 0;
163 TileFinder tileFinder = new TileFinder();
164 String errorMessage = null;
165 final int numTiles = inTileSet.size();
167 // Update progress bar
168 if (_progress != null)
170 _progress.setMaximum(numTiles);
171 _progress.setValue(0);
173 int currentTileIndex = 0;
175 for (SrtmTile tile : inTileSet)
177 URL url = tileFinder.getUrl(tile);
183 _progress.setValue(currentTileIndex++);
184 final int ARRLENGTH = 1201 * 1201;
185 int[] heights = new int[ARRLENGTH];
186 // Open zipinputstream on url and check size
187 ZipInputStream inStream = getStreamToSrtmData(url);
188 boolean entryOk = false;
189 if (inStream != null)
191 ZipEntry entry = inStream.getNextEntry();
192 entryOk = (entry != null && entry.getSize() == HGT_SIZE);
195 // Read entire file contents into one byte array
196 for (int i = 0; i < ARRLENGTH; i++)
198 heights[i] = inStream.read() * 256 + inStream.read();
199 if (heights[i] >= 32768) {heights[i] -= 65536;}
203 // System.out.println("length not ok: " + entry.getSize());
205 // Close stream from url
211 numAltitudesFound += applySrtmTileToWholeTrack(tile, heights, inOverwriteZeros);
214 catch (IOException ioe) {
215 errorMessage = ioe.getClass().getName() + " - " + ioe.getMessage();
221 if (_progress.isCancelled()) {
225 if (numAltitudesFound > 0)
227 // Inform app including undo information
228 _track.requestRescale();
229 UpdateMessageBroker.informSubscribers(DataSubscriber.DATA_ADDED_OR_REMOVED);
230 // Don't update app if we're doing another track
233 _app.completeFunction(undo,
234 I18nManager.getTextWithNumber("confirm.lookupsrtm", numAltitudesFound));
237 else if (errorMessage != null) {
238 _app.showErrorMessageNoLookup(getNameKey(), errorMessage);
240 else if (numTiles > 0) {
241 _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonefound");
244 _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonerequired");
249 * See whether the SRTM file is already available locally first, then try online
250 * @param inUrl URL for online resource
251 * @return ZipInputStream either on the local file or on the downloaded zip file
253 private ZipInputStream getStreamToSrtmData(URL inUrl)
256 ZipInputStream localData = null;
258 localData = getStreamToLocalHgtFile(inUrl);
260 catch (IOException ioe) {
263 if (localData != null)
267 // try to download to cache
268 TileDownloader cacher = new TileDownloader();
269 TileDownloader.Result result = cacher.downloadTile(inUrl);
270 System.out.println("Result: " + result);
271 if (result == TileDownloader.Result.DOWNLOADED)
274 return getStreamToLocalHgtFile(inUrl);
276 // If we don't have a cache, we may be able to download it temporarily
277 if (result != TileDownloader.Result.DOWNLOAD_FAILED)
279 _hadToDownload = true;
280 return new ZipInputStream(inUrl.openStream());
287 * Get the SRTM file from the local cache, if available
288 * @param inUrl URL for online resource
289 * @return ZipInputStream on the local file or null if not there
291 private ZipInputStream getStreamToLocalHgtFile(URL inUrl)
294 String diskCachePath = Config.getConfigString(Config.KEY_DISK_CACHE);
295 if (diskCachePath != null)
297 File srtmDir = new File(diskCachePath, "srtm");
298 if (srtmDir.exists() && srtmDir.isDirectory() && srtmDir.canRead())
300 File srtmFile = new File(srtmDir, new File(inUrl.getFile()).getName());
301 if (srtmFile.exists() && srtmFile.isFile() && srtmFile.canRead()
302 && srtmFile.length() > 400)
304 // System.out.println("Lookup: Using file " + srtmFile.getAbsolutePath());
305 // File found, use this one
306 return new ZipInputStream(new FileInputStream(srtmFile));
314 * Given the height data read in from file, apply the given tile to all points
315 * in the track with missing altitude
316 * @param inTile tile being applied
317 * @param inHeights height data read in from file
318 * @param inOverwriteZeros true to overwrite zero altitude values
319 * @return number of altitudes found
321 private int applySrtmTileToWholeTrack(SrtmTile inTile, int[] inHeights, boolean inOverwriteZeros)
323 int numAltitudesFound = 0;
324 // Loop over all points in track, try to apply altitude from array
325 for (int p = 0; p < _track.getNumPoints(); p++)
327 DataPoint point = _track.getPoint(p);
328 if (new SrtmTile(point).equals(inTile))
330 double x = (point.getLongitude().getDouble() - inTile.getLongitude()) * 1200;
331 double y = 1201 - (point.getLatitude().getDouble() - inTile.getLatitude()) * 1200;
332 int idx1 = ((int)y)*1201 + (int)x;
335 int[] fouralts = {inHeights[idx1], inHeights[idx1+1], inHeights[idx1-1201], inHeights[idx1-1200]};
336 int numVoids = (fouralts[0]==VOID_VAL?1:0) + (fouralts[1]==VOID_VAL?1:0)
337 + (fouralts[2]==VOID_VAL?1:0) + (fouralts[3]==VOID_VAL?1:0);
338 // if (numVoids > 0) System.out.println(numVoids + " voids found");
339 double altitude = 0.0;
342 case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
343 case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
345 case 3: altitude = averageNonVoid(fouralts); break;
346 default: altitude = VOID_VAL;
348 // Special case for terrain tracks, don't interpolate voids yet
349 if (!_normalTrack && numVoids > 0) {
352 if (altitude != VOID_VAL)
354 point.setFieldValue(Field.ALTITUDE, ""+altitude, false);
355 // depending on settings, this value may have been added as feet, we need to force metres
356 point.getAltitude().reset(new Altitude((int)altitude, UnitSetLibrary.UNITS_METRES));
360 catch (ArrayIndexOutOfBoundsException obe) {
361 // System.err.println("lat=" + point.getLatitude().getDouble() + ", x=" + x + ", y=" + y + ", idx=" + idx1);
365 return numAltitudesFound;
369 * Perform a bilinear interpolation on the given altitude array
370 * @param inAltitudes array of four altitude values on corners of square (bl, br, tl, tr)
371 * @param inX x coordinate
372 * @param inY y coordinate
373 * @return interpolated altitude
375 private static double bilinearInterpolate(int[] inAltitudes, double inX, double inY)
377 double alpha = inX - (int) inX;
378 double beta = 1 - (inY - (int) inY);
379 double alt = (1-alpha)*(1-beta)*inAltitudes[0] + alpha*(1-beta)*inAltitudes[1]
380 + (1-alpha)*beta*inAltitudes[2] + alpha*beta*inAltitudes[3];
385 * Fix a single void in the given array by replacing it with the average of the others
386 * @param inAltitudes array of altitudes containing one void
387 * @return fixed array without voids
389 private static int[] fixVoid(int[] inAltitudes)
391 int[] fixed = new int[inAltitudes.length];
392 for (int i = 0; i < inAltitudes.length; i++)
394 if (inAltitudes[i] == VOID_VAL) {
395 fixed[i] = (int) Math.round(averageNonVoid(inAltitudes));
398 fixed[i] = inAltitudes[i];
405 * Calculate the average of the non-void altitudes in the given array
406 * @param inAltitudes array of altitudes with one or more voids
407 * @return average of non-void altitudes
409 private static final double averageNonVoid(int[] inAltitudes)
411 double totalAltitude = 0.0;
413 for (int i = 0; i < inAltitudes.length; i++)
415 if (inAltitudes[i] != VOID_VAL)
417 totalAltitude += inAltitudes[i];
421 if (numAlts < 1) {return VOID_VAL;}
422 return totalAltitude / numAlts;
426 * @return true if a thread is currently running
428 public boolean isRunning()
433 private void showConfirmMessage(int numDownloaded)
435 if (numDownloaded == 1)
437 JOptionPane.showMessageDialog(_parentFrame, I18nManager.getTextWithNumber("confirm.downloadsrtm.1", numDownloaded),
438 I18nManager.getText(getNameKey()), JOptionPane.INFORMATION_MESSAGE);
440 else if (numDownloaded > 1)
442 JOptionPane.showMessageDialog(_parentFrame, I18nManager.getTextWithNumber("confirm.downloadsrtm", numDownloaded),
443 I18nManager.getText(getNameKey()), JOptionPane.INFORMATION_MESSAGE);