tim/prune/function/srtm/LookupSrtmFunction.java

   1 package tim.prune.function.srtm;
   2
   3 import java.awt.BorderLayout;
   4 import java.awt.Component;
   5 import java.awt.Dimension;
   6 import java.awt.FlowLayout;
   7 import java.awt.event.ActionEvent;
   8 import java.awt.event.ActionListener;
   9 import java.io.IOException;
  10 import java.net.URL;
  11 import java.util.ArrayList;
  12 import java.util.zip.ZipEntry;
  13 import java.util.zip.ZipInputStream;
  14
  15 import javax.swing.JButton;
  16 import javax.swing.JDialog;
  17 import javax.swing.JLabel;
  18 import javax.swing.JOptionPane;
  19 import javax.swing.JPanel;
  20 import javax.swing.JProgressBar;
  21
  22 import tim.prune.App;
  23 import tim.prune.DataSubscriber;
  24 import tim.prune.GenericFunction;
  25 import tim.prune.I18nManager;
  26 import tim.prune.UpdateMessageBroker;
  27 import tim.prune.data.DataPoint;
  28 import tim.prune.data.Field;
  29 import tim.prune.data.Track;
  30 import tim.prune.undo.UndoLookupSrtm;
  31
  32 /**
  33  * Class to provide a lookup function for point altitudes
  34  * using the Space Shuttle's SRTM data files.
  35  * HGT files are downloaded into memory via HTTP and point altitudes
  36  * can then be interpolated from the 3m grid data.
  37  */
  38 public class LookupSrtmFunction extends GenericFunction implements Runnable
  39 {
  40         /** function dialog */
  41         private JDialog _dialog = null;
  42         /** Progress bar for function */
  43         private JProgressBar _progressBar = null;
  44         /** Cancel flag */
  45         private boolean _cancelled = false;
  46
  47         /** Expected size of hgt file in bytes */
  48         private static final long HGT_SIZE = 2884802L;
  49         /** Altitude below which is considered void */
  50         private static final int VOID_VAL = -32768;
  51
  52
  53         /**
  54          * Constructor
  55          * @param inApp App object
  56          */
  57         public LookupSrtmFunction(App inApp)
  58         {
  59                 super(inApp);
  60         }
  61
  62         /** @return name key */
  63         public String getNameKey() {
  64                 return "function.lookupsrtm";
  65         }
  66
  67         /**
  68          * Begin the lookup
  69          */
  70         public void begin()
  71         {
  72                 if (_dialog == null)
  73                 {
  74                         _dialog = new JDialog(_parentFrame, I18nManager.getText(getNameKey()), false);
  75                         _dialog.setLocationRelativeTo(_parentFrame);
  76                         _dialog.getContentPane().add(makeDialogComponents());
  77                         _dialog.pack();
  78                 }
  79                 _progressBar.setMinimum(0);
  80                 _progressBar.setMaximum(100);
  81                 _progressBar.setValue(20);
  82                 _cancelled = false;
  83                 // start new thread for time-consuming part
  84                 new Thread(this).start();
  85         }
  86
  87
  88         /**
  89          * Make the dialog components
  90          * @return the GUI components for the dialog
  91          */
  92         private Component makeDialogComponents()
  93         {
  94                 JPanel dialogPanel = new JPanel();
  95                 dialogPanel.setLayout(new BorderLayout());
  96                 dialogPanel.add(new JLabel(I18nManager.getText("confirm.running")), BorderLayout.NORTH);
  97                 _progressBar = new JProgressBar();
  98                 _progressBar.setPreferredSize(new Dimension(250, 30));
  99                 dialogPanel.add(_progressBar, BorderLayout.CENTER);
 100                 // Cancel button at the bottom
 101                 JPanel buttonPanel = new JPanel();
 102                 buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
 103                 JButton cancelButton = new JButton(I18nManager.getText("button.cancel"));
 104                 cancelButton.addActionListener(new ActionListener() {
 105                         public void actionPerformed(ActionEvent e) {
 106                                 _cancelled = true;
 107                         }
 108                 });
 109                 buttonPanel.add(cancelButton);
 110                 dialogPanel.add(buttonPanel, BorderLayout.SOUTH);
 111                 return dialogPanel;
 112         }
 113
 114         /**
 115          * Run method using separate thread
 116          */
 117         public void run()
 118         {
 119                 // Compile list of tiles to get
 120                 Track track = _app.getTrackInfo().getTrack();
 121                 ArrayList<SrtmTile> tileList = new ArrayList<SrtmTile>();
 122                 boolean hasZeroAltitudePoints = false;
 123                 boolean hasNonZeroAltitudePoints = false;
 124                 // First, loop to see what kind of points we have
 125                 for (int i=0; i<track.getNumPoints(); i++)
 126                 {
 127                         if (track.getPoint(i).hasAltitude())
 128                         {
 129                                 if (track.getPoint(i).getAltitude().getValue() == 0) {
 130                                         hasZeroAltitudePoints = true;
 131                                 }
 132                                 else {
 133                                         hasNonZeroAltitudePoints = true;
 134                                 }
 135                         }
 136                 }
 137                 // Should we overwrite the zero altitude values?
 138                 boolean overwriteZeros = hasZeroAltitudePoints && !hasNonZeroAltitudePoints;
 139                 // If non-zero values present as well, ask user whether to overwrite the zeros or not
 140                 if (hasNonZeroAltitudePoints && hasZeroAltitudePoints && JOptionPane.showConfirmDialog(_parentFrame,
 141                         I18nManager.getText("dialog.lookupsrtm.overwritezeros"), I18nManager.getText(getNameKey()),
 142                         JOptionPane.YES_NO_OPTION) == JOptionPane.YES_OPTION)
 143                 {
 144                         overwriteZeros = true;
 145                 }
 146
 147                 _dialog.setVisible(true);
 148                 // Now loop again to extract the required tiles
 149                 for (int i=0; i<track.getNumPoints(); i++)
 150                 {
 151                         // Consider points which don't have altitudes or have zero values
 152                         if (!track.getPoint(i).hasAltitude() || (overwriteZeros && track.getPoint(i).getAltitude().getValue() == 0))
 153                         {
 154                                 SrtmTile tile = new SrtmTile(track.getPoint(i));
 155                                 boolean alreadyGot = false;
 156                                 for (int t=0; t<tileList.size(); t++) {
 157                                         if (tileList.get(t).equals(tile)) {
 158                                                 alreadyGot = true;
 159                                         }
 160                                 }
 161                                 if (!alreadyGot) {tileList.add(tile);}
 162                         }
 163                 }
 164                 lookupValues(tileList, overwriteZeros);
 165         }
 166
 167         /**
 168          * Lookup the values from SRTM data
 169          * @param inTileList list of tiles to get
 170          * @param inOverwriteZeros true to overwrite zero altitude values
 171          */
 172         private void lookupValues(ArrayList<SrtmTile> inTileList, boolean inOverwriteZeros)
 173         {
 174                 Track track = _app.getTrackInfo().getTrack();
 175                 UndoLookupSrtm undo = new UndoLookupSrtm(_app.getTrackInfo());
 176                 int numAltitudesFound = 0;
 177                 // Update progress bar
 178                 _progressBar.setMaximum(inTileList.size());
 179                 _progressBar.setIndeterminate(inTileList.size() <= 1);
 180                 _progressBar.setValue(0);
 181                 // Get urls for each tile
 182                 URL[] urls = TileFinder.getUrls(inTileList);
 183                 for (int t=0; t<inTileList.size() && !_cancelled; t++)
 184                 {
 185                         if (urls[t] != null)
 186                         {
 187                                 SrtmTile tile = inTileList.get(t);
 188                                 // System.out.println("tile " + t + " of " + tileList.size() + " = " + urls[t].toString());
 189                                 try {
 190                                         _progressBar.setValue(t);
 191                                         final int ARRLENGTH = 1201*1201;
 192                                         int[] heights = new int[ARRLENGTH];
 193                                         // Open zipinputstream on url and check size
 194                                         ZipInputStream inStream = new ZipInputStream(urls[t].openStream());
 195                                         ZipEntry entry = inStream.getNextEntry();
 196                                         boolean entryOk = (entry.getSize() == HGT_SIZE);
 197                                         if (entryOk)
 198                                         {
 199                                                 // Read entire file contents into one byte array
 200                                                 for (int i=0; i<ARRLENGTH; i++) {
 201                                                         heights[i] = inStream.read()*256 + inStream.read();
 202                                                         if (heights[i] >= 32768) {heights[i] -= 65536;}
 203                                                 }
 204                                         }
 205                                         //else {
 206                                         //      System.out.println("length not ok: " + entry.getSize());
 207                                         //}
 208                                         // Close stream from url
 209                                         inStream.close();
 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() || (inOverwriteZeros && point.getAltitude().getValue() == 0)) {
 218                                                                 if (new SrtmTile(point).equals(tile))
 219                                                                 {
 220                                                                         double x = (point.getLongitude().getDouble() - tile.getLongitude()) * 1200;
 221                                                                         double y = 1201 - (point.getLatitude().getDouble() - tile.getLatitude()) * 1200;
 222                                                                         int idx1 = ((int)y)*1201 + (int)x;
 223                                                                         try {
 224                                                                                 int[] fouralts = {heights[idx1], heights[idx1+1], heights[idx1-1201], heights[idx1-1200]};
 225                                                                                 int numVoids = (fouralts[0]==VOID_VAL?1:0) + (fouralts[1]==VOID_VAL?1:0)
 226                                                                                         + (fouralts[2]==VOID_VAL?1:0) + (fouralts[3]==VOID_VAL?1:0);
 227                                                                                 // if (numVoids > 0) System.out.println(numVoids + " voids found");
 228                                                                                 double altitude = 0.0;
 229                                                                                 switch (numVoids) {
 230                                                                                         case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
 231                                                                                         case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
 232                                                                                         case 2:
 233                                                                                         case 3: altitude = averageNonVoid(fouralts); break;
 234                                                                                         default: altitude = VOID_VAL;
 235                                                                                 }
 236                                                                                 if (altitude != VOID_VAL) {
 237                                                                                         point.setFieldValue(Field.ALTITUDE, ""+altitude, false);
 238                                                                                         numAltitudesFound++;
 239                                                                                 }
 240                                                                         }
 241                                                                         catch (ArrayIndexOutOfBoundsException obe) {
 242                                                                                 //System.err.println("lat=" + point.getLatitude().getDouble() + ", x=" + x + ", y=" + y + ", idx=" + idx1);
 243                                                                         }
 244                                                                 }
 245                                                         }
 246                                                 }
 247                                         }
 248                                 }
 249                                 catch (IOException ioe) {
 250                                         //System.err.println("eek - " + ioe.getMessage());
 251                                 }
 252                         }
 253                 }
 254                 _dialog.dispose();
 255                 if (numAltitudesFound > 0)
 256                 {
 257                         // Inform app including undo information
 258                         track.requestRescale();
 259                         UpdateMessageBroker.informSubscribers(DataSubscriber.DATA_ADDED_OR_REMOVED);
 260                         _app.completeFunction(undo, I18nManager.getText("confirm.lookupsrtm1") + " " + numAltitudesFound
 261                                 + " " + I18nManager.getText("confirm.lookupsrtm2"));
 262                 }
 263                 else if (inTileList.size() > 0) {
 264                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonefound");
 265                 }
 266                 else {
 267                         _app.showErrorMessage(getNameKey(), "error.lookupsrtm.nonerequired");
 268                 }
 269         }
 270
 271         /**
 272          * Perform a bilinear interpolation on the given altitude array
 273          * @param inAltitudes array of four altitude values on corners of square (bl, br, tl, tr)
 274          * @param inX x coordinate
 275          * @param inY y coordinate
 276          * @return interpolated altitude
 277          */
 278         private static double bilinearInterpolate(int[] inAltitudes, double inX, double inY)
 279         {
 280                 double alpha = inX - (int) inX;
 281                 double beta  = 1 - (inY - (int) inY);
 282                 double alt = (1-alpha)*(1-beta)*inAltitudes[0] + alpha*(1-beta)*inAltitudes[1]
 283                         + (1-alpha)*beta*inAltitudes[2] + alpha*beta*inAltitudes[3];
 284                 return alt;
 285         }
 286
 287         /**
 288          * Fix a single void in the given array by replacing it with the average of the others
 289          * @param inAltitudes array of altitudes containing one void
 290          * @return fixed array without voids
 291          */
 292         private static int[] fixVoid(int[] inAltitudes)
 293         {
 294                 int[] fixed = new int[inAltitudes.length];
 295                 for (int i=0; i<inAltitudes.length; i++) {
 296                         if (inAltitudes[i] == VOID_VAL) {
 297                                 fixed[i] = (int) Math.round(averageNonVoid(inAltitudes));
 298                         }
 299                         else {
 300                                 fixed[i] = inAltitudes[i];
 301                         }
 302                 }
 303                 return fixed;
 304         }
 305
 306         /**
 307          * Calculate the average of the non-void altitudes in the given array
 308          * @param inAltitudes array of altitudes with one or more voids
 309          * @return average of non-void altitudes
 310          */
 311         private static final double averageNonVoid(int[] inAltitudes)
 312         {
 313                 double totalAltitude = 0.0;
 314                 int numAlts = 0;
 315                 for (int i=0; i<inAltitudes.length; i++) {
 316                         if (inAltitudes[i] != VOID_VAL) {
 317                                 totalAltitude += inAltitudes[i];
 318                                 numAlts++;
 319                         }
 320                 }
 321                 if (numAlts < 1) {return VOID_VAL;}
 322                 return totalAltitude / numAlts;
 323         }
 324 }