/********************************************************************************

* Copyright (C) 2015 by Simon Wendsche *

* *

* This file is part of NormalmapGenerator. *

* *

* NormalmapGenerator 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. *

* *

* NormalmapGenerator 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 this program. If not, see <http://www.gnu.org/licenses/>. *

* *

* Sourcecode: https://github.com/Theverat/NormalmapGenerator *

********************************************************************************/

#include "boxblur.h"

#include <iostream>

BoxBlur::BoxBlur()

{

}

IntensityMap BoxBlur::calculate(IntensityMap input, int radius, bool tileable) {

IntensityMap result = IntensityMap(input.getWidth(), input.getHeight());

int kernelPixelAmount = (2 * radius + 1) * (2 * radius + 1);

#pragma omp parallel for // OpenMP

for(size_t y = 0; y < input.getHeight(); y++) {

for(size_t x = 0; x < input.getWidth(); x++) {

float sum = 0.0;

//blur kernel loops

for(int i = -radius; i < radius; i++) {

for(int k = -radius; k < radius; k++) {

int posY = handleEdges(y + i, input.getHeight(), tileable);

int posX = handleEdges(x + k, input.getWidth(), tileable);

sum += input.at(posX, posY);

}

}

//normalize sum

sum /= kernelPixelAmount;

result.setValue(x, y, sum);

}

}

return result;

}

int BoxBlur::handleEdges(int iterator, int max, bool tileable) {

if(iterator < 0) {

if(tileable) {

int corrected = max + iterator;

//failsafe, e.g. if filter size is larger than image size

return handleEdges(corrected, max, false);

}

else {

return 0;

}

}

if(iterator >= max) {

if(tileable) {

int corrected = iterator - max;

//failsafe, e.g. if filter size is larger than image size

return handleEdges(corrected, max, false);

}

else {

return max - 1;

}

}

return iterator;

}