1 package tim.prune.function.srtm;
4 import java.io.FileInputStream;
5 import java.io.IOException;
7 import java.util.ArrayList;
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 /** Flag to check whether this function is currently running or not */
44 private boolean _running = false;
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;
53 * @param inApp App object
55 public LookupSrtmFunction(App inApp) {
59 /** @return name key */
60 public String getNameKey() {
61 return "function.lookupsrtm";
65 * Begin the lookup using the normal track
68 begin(_app.getTrackInfo().getTrack(), true);
72 * Begin the lookup with an alternative track
73 * @param inAlternativeTrack
75 public void begin(Track inAlternativeTrack) {
76 begin(inAlternativeTrack, false);
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
84 private void begin(Track inTrack, boolean inNormalTrack)
87 _hadToDownload = false;
88 if (_progress == null) {
89 _progress = new ProgressDialog(_parentFrame, getNameKey());
93 _normalTrack = inNormalTrack;
94 // start new thread for time-consuming part
95 new Thread(this).start();
99 * Run method using separate thread
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++)
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 for (int i = 0; i < _track.getNumPoints(); i++)
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))
137 SrtmTile tile = new SrtmTile(_track.getPoint(i));
138 boolean alreadyGot = false;
139 for (int t = 0; t < tileList.size(); t++)
141 if (tileList.get(t).equals(tile)) {
145 if (!alreadyGot) {tileList.add(tile);}
148 lookupValues(tileList, overwriteZeros);
151 // Show tip if lots of online lookups were necessary
152 if (_hadToDownload) {
153 _app.showTip(TipManager.Tip_DownloadSrtm);
159 * Lookup the values from SRTM data
160 * @param inTileList list of tiles to get
161 * @param inOverwriteZeros true to overwrite zero altitude values
163 private void lookupValues(ArrayList<SrtmTile> inTileList, boolean inOverwriteZeros)
165 UndoLookupSrtm undo = new UndoLookupSrtm(_app.getTrackInfo());
166 int numAltitudesFound = 0;
167 // Update progress bar
168 if (_progress != null)
170 _progress.setMaximum(inTileList.size());
171 _progress.setValue(0);
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++)
180 SrtmTile tile = inTileList.get(t);
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)
192 ZipEntry entry = inStream.getNextEntry();
193 entryOk = (entry != null && entry.getSize() == HGT_SIZE);
196 // Read entire file contents into one byte array
197 for (int i = 0; i < ARRLENGTH; i++)
199 heights[i] = inStream.read() * 256 + inStream.read();
200 if (heights[i] >= 32768) {heights[i] -= 65536;}
204 // System.out.println("length not ok: " + entry.getSize());
206 // Close stream from url
212 // Loop over all points in track, try to apply altitude from array
213 for (int p = 0; p < _track.getNumPoints(); p++)
215 DataPoint point = _track.getPoint(p);
216 if (!point.hasAltitude()
217 || (inOverwriteZeros && point.getAltitude().getValue() == 0))
219 if (new SrtmTile(point).equals(tile))
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;
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;
233 case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
234 case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
236 case 3: altitude = averageNonVoid(fouralts); break;
237 default: altitude = VOID_VAL;
239 // Special case for terrain tracks, don't interpolate voids yet
240 if (!_normalTrack && numVoids > 0) {
243 if (altitude != VOID_VAL)
245 point.setFieldValue(Field.ALTITUDE, ""+altitude, false);
246 // depending on settings, this value may have been added as feet, we need to force metres
247 point.getAltitude().reset(new Altitude((int)altitude, UnitSetLibrary.UNITS_METRES));
251 catch (ArrayIndexOutOfBoundsException obe) {
252 // System.err.println("lat=" + point.getLatitude().getDouble() + ", x=" + x + ", y=" + y + ", idx=" + idx1);
259 catch (IOException ioe) {errorMessage = ioe.getClass().getName() + " - " + ioe.getMessage();
265 if (_progress.isCancelled()) {
269 if (numAltitudesFound > 0)
271 // Inform app including undo information
272 _track.requestRescale();
273 UpdateMessageBroker.informSubscribers(DataSubscriber.DATA_ADDED_OR_REMOVED);
274 // Don't update app if we're doing another track
277 _app.completeFunction(undo,
278 I18nManager.getTextWithNumber("confirm.lookupsrtm", numAltitudesFound));
281 else if (errorMessage != null) {
282 _app.showErrorMessageNoLookup(getNameKey(), errorMessage);
284 else if (inTileList.size() > 0) {
285 _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonefound");
288 _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonerequired");
293 * See whether the SRTM file is already available locally first, then try online
294 * @param inUrl URL for online resource
295 * @return ZipInputStream either on the local file or on the downloaded zip file
297 private ZipInputStream getStreamToHgtFile(URL inUrl)
300 String diskCachePath = Config.getConfigString(Config.KEY_DISK_CACHE);
301 if (diskCachePath != null)
303 File srtmDir = new File(diskCachePath, "srtm");
304 if (srtmDir.exists() && srtmDir.isDirectory() && srtmDir.canRead())
306 File srtmFile = new File(srtmDir, new File(inUrl.getFile()).getName());
307 if (srtmFile.exists() && srtmFile.isFile() && srtmFile.canRead()
308 && srtmFile.length() > 400)
310 // System.out.println("Lookup: Using file " + srtmFile.getAbsolutePath());
311 // File found, use this one
312 return new ZipInputStream(new FileInputStream(srtmFile));
316 // System.out.println("Lookup: Trying online: " + inUrl.toString());
317 _hadToDownload = true;
318 // MAYBE: Only download if we're in online mode?
319 return new ZipInputStream(inUrl.openStream());
323 * Perform a bilinear interpolation on the given altitude array
324 * @param inAltitudes array of four altitude values on corners of square (bl, br, tl, tr)
325 * @param inX x coordinate
326 * @param inY y coordinate
327 * @return interpolated altitude
329 private static double bilinearInterpolate(int[] inAltitudes, double inX, double inY)
331 double alpha = inX - (int) inX;
332 double beta = 1 - (inY - (int) inY);
333 double alt = (1-alpha)*(1-beta)*inAltitudes[0] + alpha*(1-beta)*inAltitudes[1]
334 + (1-alpha)*beta*inAltitudes[2] + alpha*beta*inAltitudes[3];
339 * Fix a single void in the given array by replacing it with the average of the others
340 * @param inAltitudes array of altitudes containing one void
341 * @return fixed array without voids
343 private static int[] fixVoid(int[] inAltitudes)
345 int[] fixed = new int[inAltitudes.length];
346 for (int i = 0; i < inAltitudes.length; i++)
348 if (inAltitudes[i] == VOID_VAL) {
349 fixed[i] = (int) Math.round(averageNonVoid(inAltitudes));
352 fixed[i] = inAltitudes[i];
359 * Calculate the average of the non-void altitudes in the given array
360 * @param inAltitudes array of altitudes with one or more voids
361 * @return average of non-void altitudes
363 private static final double averageNonVoid(int[] inAltitudes)
365 double totalAltitude = 0.0;
367 for (int i = 0; i < inAltitudes.length; i++)
369 if (inAltitudes[i] != VOID_VAL)
371 totalAltitude += inAltitudes[i];
375 if (numAlts < 1) {return VOID_VAL;}
376 return totalAltitude / numAlts;
380 * @return true if a thread is currently running
382 public boolean isRunning()