cmtkVolumeGridToGridLookup.cxx

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/*
//
//  Copyright 1997-2009 Torsten Rohlfing
//
//  Copyright 2004-2010 SRI International
//
//  This file is part of the Computational Morphometry Toolkit.
//
//  http://www.nitrc.org/projects/cmtk/
//
//  The Computational Morphometry Toolkit is free software: you can
//  redistribute it and/or modify it under the terms of the GNU General Public
//  License as published by the Free Software Foundation, either version 3 of
//  the License, or (at your option) any later version.
//
//  The Computational Morphometry Toolkit is distributed in the hope that it
//  will be useful, but WITHOUT ANY WARRANTY; without even the implied
//  warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License along
//  with the Computational Morphometry Toolkit.  If not, see
//  <http://www.gnu.org/licenses/>.
//
//  $Revision: 2398 $
//
//  $LastChangedDate: 2010-10-05 14:54:37 -0700 (Tue, 05 Oct 2010) $
//
//  $LastChangedBy: torstenrohlfing $
//
*/

#include "cmtkVolumeGridToGridLookup.h"

#include <Base/cmtkVolume.h>

namespace
cmtk
{


VolumeGridToGridLookup
::VolumeGridToGridLookup( const UniformVolume& fromVolume, const UniformVolume& toVolume )
  : m_SourceCount( 3 ), m_FromIndex( 3 ), m_Weight( 3 ), m_Length( 3 )
{
  for ( int dim = 0; dim < 3; ++dim )
    {
    const Types::Coordinate fromGridDelta = fromVolume.m_Delta[dim];
    const Types::Coordinate toGridDelta = toVolume.m_Delta[dim];

    this->m_SourceCount[dim].resize( toVolume.m_Dims[dim]+1 );
    this->m_FromIndex[dim].resize( toVolume.m_Dims[dim]+1 );
    this->m_Weight[dim].resize( toVolume.m_Dims[dim]+1 );
    this->m_Length[dim].resize( toVolume.m_Dims[dim]+1 );

    std::vector<Types::Coordinate> weightList( fromVolume.m_Dims[dim] );
    
    int fromIdx = 0;
    for ( int toIdx = 0; toIdx < toVolume.m_Dims[dim]; ++toIdx ) 
      {
      const Types::Coordinate toGridLo = std::max<Types::Coordinate>( 0.0, (toIdx-0.5) * toGridDelta );
      const Types::Coordinate toGridHi = std::min<Types::Coordinate>( toVolume.Size[dim], (0.5+toIdx) * toGridDelta );
      this->m_Length[dim][toIdx] = toGridHi - toGridLo;

      Types::Coordinate fromGridHi = std::min<Types::Coordinate>( toVolume.Size[dim], (0.5+fromIdx) * fromGridDelta );
      while ( toGridLo>=fromGridHi )
        {
        ++fromIdx;
        fromGridHi += fromGridDelta;
        }
      this->m_FromIndex[dim][toIdx] = fromIdx;
      fromGridHi = std::min<Types::Coordinate>( fromVolume.Size[dim], fromGridHi );
      
      int idx = 0;
      Types::Coordinate fromGridLo = std::max<Types::Coordinate>( 0.0, (fromIdx-0.5) * fromGridDelta );
      for ( int p = fromIdx; (p < fromVolume.m_Dims[dim]) && (fromGridLo < toGridHi); ++p, ++idx )
        {
        weightList[idx] = MathUtil::Intersect( toGridLo, toGridHi, fromGridLo, fromGridHi );
        fromGridLo = (p+0.5) * fromGridDelta;   
        fromGridHi += fromGridDelta;
        }
      
      this->m_SourceCount[dim][toIdx] = idx;
      this->m_Weight[dim][toIdx].resize( idx );
      for ( int i = 0; i < idx; ++i )
        this->m_Weight[dim][toIdx][i] = weightList[i];
      }
    
    this->m_Weight[dim][toVolume.m_Dims[dim]].resize(0);
    }
}

} // namespace cmtk