geo/tcSrtmCache.h

   1 /***************************************************************************
   2  *   This file is part of Tecorrec.                                        *
   3  *   Copyright 2008 James Hogan <james@albanarts.com>                      *
   4  *                                                                         *
   5  *   Tecorrec is free software: you can redistribute it and/or modify      *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation, either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   Tecorrec is distributed in the hope that it will be useful,           *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with Tecorrec.  If not, write to the Free Software Foundation,  *
  17  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   *
  18  ***************************************************************************/
  19
  20 #ifndef _tcSrtmCache_h_
  21 #define _tcSrtmCache_h_
  22
  23 /**
  24  * @file tcSrtmCache.h
  25  * @brief Manages cache of SRTM data.
  26  */
  27
  28 #include <QObject>
  29 #include <QString>
  30 #include <QStringList>
  31 #include <QDir>
  32
  33 class tcSrtmData;
  34 class tcGeo;
  35 class tcElevationData;
  36
  37 /** Manages cache of SRTM data.
  38  * Obtains SRTM elevation data blocks, downloading from nasa if necessary.
  39  *
  40  * FTP site: ftp://e0srp01u.ecs.nasa.gov/
  41  */
  42 class tcSrtmCache : public QObject
  43 {
  44     Q_OBJECT
  45
  46   public:
  47
  48     /*
  49      * Static functions
  50      */
  51
  52     /// Get a list of datasets.
  53     static QStringList dataSets();
  54
  55     /*
  56      * Constructors + destructor
  57      */
  58
  59     /// Primary constructor.
  60     tcSrtmCache(const QString& dataSet);
  61
  62     /// Destructor.
  63     virtual ~tcSrtmCache();
  64
  65     /*
  66      * Main interface
  67      */
  68
  69     /** Load raw SRTM height file.
  70      * Download the file if necessary.
  71      * @param lon Longitude in degrees.
  72      * @param lat Latitude in degrees.
  73      * @returns SRTM data for the chunk containing (@p lon, @p lat) or 0.
  74      */
  75     tcSrtmData* loadData(int lon, int lat);
  76
  77     /** Load raw SRTM height file.
  78      * Download the file if necessary.
  79      * @param coord Geographical coordinate.
  80      * @returns SRTM data for the chunk containing (@p lon, @p lat) or 0.
  81      */
  82     tcSrtmData* loadData(const tcGeo& coord);
  83
  84     /** Find some SRTM height data overlapping an area.
  85      * @param swCorner Geographical coordinate of south-west corner.
  86      * @param neCorner Geographical coordinate of north-east corner.
  87      * @returns An arbitrary SRTM data for a chunk in the lon lat range.
  88      */
  89     tcSrtmData* findData(const tcGeo& swCorner, const tcGeo& neCorner);
  90
  91     /// Update any samples affected by the elevation field.
  92     void updateFromElevationData(const tcElevationData* elevation);
  93
  94   signals:
  95
  96     /*
  97      * Signals
  98      */
  99
 100     /// Progress notification.
 101     void progressing(const QString& message);
 102
 103   private:
 104
 105     /*
 106      * Private functions
 107      */
 108
 109     /// Convert a geographical coordinate into lon lat ints.
 110     void toIntLonLat(const tcGeo& coord, int* const outLon, int* const outLat);
 111
 112     /// Cache index.
 113     tcSrtmData*& cache(int lon, int lat);
 114
 115   private:
 116
 117     /*
 118      * Static variables
 119      */
 120
 121     /// Directory containing elevation data sets.
 122     static QDir s_dataDirectory;
 123
 124     /*
 125      * Variables
 126      */
 127
 128     /// Dataset name.
 129     QString m_dataSet;
 130
 131     /// Cache of data at each grid point.
 132     tcSrtmData* m_cache[360][180];
 133 };
 134
 135 #endif
 136