geo/tcChannelDem.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 tcChannelDem.cpp
  22  * @brief An abstract image channel which needs access to the digital elevation model.
  23  */
  24
  25 #include "tcChannelDem.h"
  26 #include "tcSrtmModel.h"
  27 #include "tcGeoImageData.h"
  28
  29 /*
  30  * Constructors + destructor
  31  */
  32
  33 /// Primary constructor.
  34 tcChannelDem::tcChannelDem(tcSrtmModel* dem, tcGeoImageData* imagery, const QString& name, const QString& description, bool depend1, bool depend2)
  35 : tcChannel(name, description)
  36 , m_dem(dem)
  37 , m_imagery(imagery)
  38 {
  39   if (depend1)
  40   {
  41     connect(dem, SIGNAL(dataSetChanged()), this, SLOT(invalidate()));
  42   }
  43   if (depend2)
  44   {
  45     connect(dem+1, SIGNAL(dataSetChanged()), this, SLOT(invalidate()));
  46   }
  47 }
  48
  49 /// Destructor.
  50 tcChannelDem::~tcChannelDem()
  51 {
  52 }
  53
  54 /*
  55  * Interface for derived classes to access elevation model data
  56  */
  57
  58 // Main transformation
  59
  60 /// Get the geographical coordinate at a pixel.
  61 tcGeo tcChannelDem::geoAt(const maths::Vector<2,float>& textureCoordinate, tcGeoImageData* imagery) const
  62 {
  63   if (imagery == 0)
  64   {
  65     imagery = m_imagery;
  66   }
  67   return (tcGeo)(imagery->texToGeo() * (maths::Vector<2,double>)textureCoordinate);
  68 }
  69
  70 /// Get the texture coordinate at a geographical coordinate.
  71 maths::Vector<2,float> tcChannelDem::textureAt(const tcGeo& geoCoordinate, tcGeoImageData* imagery) const
  72 {
  73   if (imagery == 0)
  74   {
  75     imagery = m_imagery;
  76   }
  77   return (maths::Vector<2,float>)(imagery->geoToTex() * geoCoordinate);
  78 }
  79
  80 // Wrapper functions
  81
  82 /// Get the altitude at a geographical coordinate.
  83 float tcChannelDem::altitudeAt(const tcGeo& coordinate, bool corrected, bool* accurate) const
  84 {
  85   return m_dem->altitudeAt(coordinate, corrected, accurate);
  86 }
  87
  88 /// Get the texture-space normal vector at a geographical coordinate.
  89 maths::Vector<3,float> tcChannelDem::normalAt(const tcGeo& coordinate, bool corrected, bool* accurate) const
  90 {
  91   return m_dem->normalAt(coordinate, corrected, accurate);
  92 }
  93
  94 /// Get the lighting direction vector at a geographical coordinate.
  95 maths::Vector<3,float> tcChannelDem::lightDirectionAt(const tcGeo& coordinate, tcGeoImageData* imagery) const
  96 {
  97   if (imagery == 0)
  98   {
  99     imagery = m_imagery;
 100   }
 101   return imagery->sunDirection(coordinate);
 102 }
 103
 104 /// Find whether a point is lit by the light.
 105 bool tcChannelDem::isLitAt(const tcGeo& coordinate, bool corrected, bool* accurate, tcGeoImageData* imagery) const
 106 {
 107   return m_dem->litAt(coordinate, lightDirectionAt(coordinate, imagery), 0.0f, corrected, accurate) > 0.5f;
 108 }
 109
 110 /// Find how lit a point is by the light.
 111 float tcChannelDem::litAt(const tcGeo& coordinate, bool corrected, bool* accurate, tcGeoImageData* imagery) const
 112 {
 113   // Sun is half a degree in the sky
 114   static const float sunSize = 0.25f * M_PI / 180.0f;
 115   return m_dem->litAt(coordinate, lightDirectionAt(coordinate, imagery), sunSize, corrected, accurate);
 116 }
 117
 118 // Lower level accessors
 119
 120 /// Get the digital elevation model.
 121 tcSrtmModel* tcChannelDem::dem() const
 122 {
 123   return m_dem;
 124 }
 125
 126 /// Get the imagery.
 127 tcGeoImageData* tcChannelDem::imagery() const
 128 {
 129   return m_imagery;
 130 }