geo/tcRaytracedShadowMap.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 tcRaytracedShadowMap.cpp
  22  * @brief Shadow map using ray tracing of DEM.
  23  */
  24
  25 #include "tcRaytracedShadowMap.h"
  26 #include "tcGeoImageData.h"
  27
  28 #include <QObject>
  29
  30 /*
  31  * Constructors + destructor
  32  */
  33
  34 /// Primary constructor.
  35 tcRaytracedShadowMap::tcRaytracedShadowMap(tcChannel* reference, tcSrtmModel* dem, tcGeoImageData* imagery)
  36 : tcChannelDem(dem, imagery,
  37                tr("Raytraced Shadow Map"),
  38                tr("Uses ray tracing and elevation data to highlight shadows."))
  39 , m_referenceChannel(reference)
  40 , m_resolution()
  41 , m_texToGeo(imagery->texToGeo())
  42 {
  43 }
  44
  45 /// Primary constructor.
  46 tcRaytracedShadowMap::tcRaytracedShadowMap(const tcGeo& resolution, tcSrtmModel* dem, tcGeoImageData* imagery)
  47 : tcChannelDem(dem, imagery,
  48                tr("Raytraced Shadow Map"),
  49                tr("Uses ray tracing and elevation data to highlight shadows."))
  50 , m_referenceChannel(0)
  51 , m_resolution(resolution)
  52 , m_texToGeo(imagery->texToGeo())
  53 {
  54 }
  55
  56 /// Destructor.
  57 tcRaytracedShadowMap::~tcRaytracedShadowMap()
  58 {
  59 }
  60
  61 /*
  62  * Interface for derived class to implement
  63  */
  64
  65 void tcRaytracedShadowMap::roundPortion(double* x1, double* y1, double* x2, double* y2)
  66 {
  67   //m_referenceChannel->roundPortion(x1,y1,x2,y2);
  68 }
  69
  70 tcAbstractPixelData* tcRaytracedShadowMap::loadPortion(double x1, double y1, double x2, double y2, bool changed)
  71 {
  72   int width;
  73   int height;
  74   if (0 != m_referenceChannel)
  75   {
  76     Reference<tcAbstractPixelData> channelData = m_referenceChannel->loadPortion(x1, y1, x2, y2, changed);
  77     width = channelData->width();
  78     height = channelData->height();
  79   }
  80   else
  81   {
  82     tcGeo diag = (tcGeo)(m_texToGeo * maths::Vector<2,double>(x1, y1) - m_texToGeo * maths::Vector<2,double>(x2,y2));
  83     maths::Vector<2,double> res = diag / m_resolution;
  84     width = abs((int)res[0]);
  85     height = abs((int)res[1]);
  86     // ensure resw and resh are powers of 2
  87     for (int i = 1; i < 20; ++i)
  88     {
  89       if (0 == (width & ~((1<<i)-1)))
  90       {
  91         width = 1<<i;
  92         break;
  93       }
  94     }
  95     for (int i = 1; i < 20; ++i)
  96     {
  97       if (0 == (height & ~((1<<i)-1)))
  98       {
  99         height = 1<<i;
 100         break;
 101       }
 102     }
 103   }
 104
 105   // Create a new pixel buffer
 106   tcPixelData<float>* data = new tcPixelData<float>(width, height);
 107   startProcessing(tr("Raytracing"));
 108   for (int j = 0; j < height; ++j)
 109   {
 110     progress((float)j/(height-1));
 111     for (int i = 0; i < width; ++i)
 112     {
 113       int index = j*width + i;
 114       // Transform coordinates
 115       maths::Vector<2,float> coord      (x1 + (x2-x1)*i / (width  - 1),
 116                                          y1 + (y2-y1)*j / (height - 1));
 117       tcGeo geoCoord = geoAt(coord);
 118       float lit = litAt(geoCoord, true);
 119
 120       data->buffer()[index] = lit;
 121     }
 122   }
 123   endProcessing();
 124   return data;
 125 }