geo/tcElevationData.cpp

   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 /**
  21  * @file tcElevationData.cpp
  22  * @brief Terrain elevation data.
  23  */
  24
  25 #include "tcElevationData.h"
  26 #include "tcSrtmData.h"
  27
  28 #include <GL/gl.h>
  29
  30 #include <cmath>
  31
  32 /*
  33  * Constructors + destructor
  34  */
  35
  36 /// Initialise from SRTM data.
  37 tcElevationData::tcElevationData(tcSrtmData* srtm)
  38 : tcGeoData(tcGeoData::ElevationData)
  39 , m_srtm(srtm)
  40 {
  41 }
  42
  43 /// Destructor.
  44 tcElevationData::~tcElevationData()
  45 {
  46 }
  47
  48 /*
  49  * Rendering
  50  */
  51
  52 void tcElevationData::renderSchematic(double meanRadius)
  53 {
  54   tcGeoData::renderSchematic(meanRadius);
  55
  56   for (int i = 0; i < m_srtm->lines(); i += 5)
  57   {
  58     glBegin(GL_LINE_STRIP);
  59     {
  60       for (int j = 0; j < m_srtm->length(); j += 1)
  61       {
  62         uint32_t alt = m_srtm->pixelAltitude(i,j);
  63         if (alt == 32768)
  64         {
  65           glEnd();
  66           glBegin(GL_LINE_STRIP);
  67           continue;
  68         }
  69         tcGeo coord = m_srtm->pixelCoordinate(i,j);
  70         double rad = meanRadius + alt;
  71         double z = cos(coord.lat());
  72         double xy = sin(coord.lat());
  73         glColor3f(1.0f, 1.0f-(float)alt/3278.0f, 0.0f);
  74         glVertex3d(rad*sin(coord.lon())*xy,
  75                    rad*cos(coord.lon())*xy,
  76                    rad*z);
  77       }
  78     }
  79     glEnd();
  80   }
  81 }