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/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#ifndef itkImageRegionSplitter_hxx
#define itkImageRegionSplitter_hxx
#include "itkImageRegionSplitter.h"
#include <cmath>
namespace itk
{
/**
*
*/
template< unsigned int VImageDimension >
unsigned int
ImageRegionSplitter< VImageDimension >
::GetNumberOfSplits(const RegionType & region, unsigned int requestedNumber)
{
const SizeType & regionSize = region.GetSize();
// split on the outermost dimension available
int splitAxis = VImageDimension - 1;
while ( regionSize[splitAxis] == 1 )
{
--splitAxis;
if ( splitAxis < 0 )
{ // cannot split
itkDebugMacro(" Cannot Split");
return 1;
}
}
// determine the actual number of pieces that will be generated
const SizeValueType range = regionSize[splitAxis];
const unsigned int valuesPerPiece = Math::Ceil< unsigned int >(range / (double)requestedNumber);
const unsigned int maxPieceUsed = Math::Ceil< unsigned int >(range / (double)valuesPerPiece) - 1;
return maxPieceUsed + 1;
}
/**
*
*/
template< unsigned int VImageDimension >
ImageRegion< VImageDimension >
ImageRegionSplitter< VImageDimension >
::GetSplit(unsigned int i, unsigned int numberOfPieces,
const RegionType & region)
{
int splitAxis;
RegionType splitRegion;
IndexType splitIndex;
SizeType splitSize, regionSize;
// Initialize the splitRegion to the requested region
splitRegion = region;
splitIndex = splitRegion.GetIndex();
splitSize = splitRegion.GetSize();
regionSize = region.GetSize();
// split on the outermost dimension available
splitAxis = VImageDimension - 1;
while ( regionSize[splitAxis] == 1 )
{
--splitAxis;
if ( splitAxis < 0 )
{ // cannot split
itkDebugMacro(" Cannot Split");
return splitRegion;
}
}
// determine the actual number of pieces that will be generated
SizeValueType range = regionSize[splitAxis];
int valuesPerPiece = Math::Ceil< int >(range / (double)numberOfPieces);
int maxPieceUsed = Math::Ceil< int >(range / (double)valuesPerPiece) - 1;
// Split the region
if ( (int)i < maxPieceUsed )
{
splitIndex[splitAxis] += i * valuesPerPiece;
splitSize[splitAxis] = valuesPerPiece;
}
if ( (int)i == maxPieceUsed )
{
splitIndex[splitAxis] += i * valuesPerPiece;
// last piece needs to process the "rest" dimension being split
splitSize[splitAxis] = splitSize[splitAxis] - i * valuesPerPiece;
}
// set the split region ivars
splitRegion.SetIndex(splitIndex);
splitRegion.SetSize(splitSize);
itkDebugMacro(" Split Piece: " << splitRegion);
return splitRegion;
}
/**
*
*/
template< unsigned int VImageDimension >
void
ImageRegionSplitter< VImageDimension >
::PrintSelf(std::ostream & os, Indent indent) const
{
Superclass::PrintSelf(os, indent);
}
} // end namespace itk
#endif
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