/*! ========================================================================
** Extended Template Library
** Box Blur Template Implementation
** $Id$
**
** Copyright (c) 2002 Robert B. Quattlebaum Jr.
**
** This package 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 2 of
** the License, or (at your option) any later version.
**
** This package 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.
**
** === N O T E S ===========================================================
**
** This is an internal header file, included by other ETL headers.
** You should not attempt to use it directly.
**
** ========================================================================= */
/* === S T A R T =========================================================== */
#ifndef __ETL__BOXBLUR_H
#define __ETL__BOXBLUR_H
/* === H E A D E R S ======================================================= */
#include <algorithm>
/* === M A C R O S ========================================================= */
/* === T Y P E D E F S ===================================================== */
/* === C L A S S E S & S T R U C T S ======================================= */
namespace etl {
template<typename T1,typename T2> void
hbox_blur(T1 pen,int w, int h, int length, T2 outpen)
{
int x,y;
typename T1::iterator_x iter, end;
length=std::min(w,length);
const float divisor(1.0f/(length*2+1));
for(y=0;y<h;y++,pen.inc_y(),outpen.inc_y())
{
iter=pen.x();
end=pen.end_x();
typename T1::accumulator_type tot((typename T1::accumulator_type)(*iter)*(length+1));
for (x=0;x<length && iter!=end;x++,++iter) tot+=*iter;
iter=pen.x();
for (x=0;x<w && iter!=end;x++,++iter,outpen.inc_x())
{
tot -= (x>length) ?
(typename T1::accumulator_type)(iter[-length-1]) :
(typename T1::accumulator_type)(*pen.x());
tot += ((x+length)<w) ?
(typename T1::accumulator_type)(iter[length]) :
(typename T1::accumulator_type)(end[-1]);
outpen.put_value((typename T2::value_type)(tot*divisor));
}
outpen.dec_x(x);
}
}
#if 1
template<typename T1,typename T2> void
vbox_blur(T1 pen,const int w, const int h, int length, T2 outpen)
{
int x,y;
typename T1::iterator_y iter, end;
length=std::min(h,length);
const float divisor(1.0f/(length*2+1));
for(x=0;x<w;x++,pen.inc_x(),outpen.inc_x())
{
iter=pen.y();
end=pen.end_y();
typename T1::accumulator_type tot((typename T1::accumulator_type)(*iter)*(length+1));
for (y=0;y<length && iter!=end;y++,++iter) tot+=*iter;
iter=pen.y();
for (y=0;y<h && iter!=end;y++,++iter,outpen.inc_y())
{
tot -= (y>length) ?
(typename T1::accumulator_type)(iter[-length-1]) :
(typename T1::accumulator_type)(*pen.y());
tot += ((y+length)<h) ?
(typename T1::accumulator_type)(iter[length]) :
(typename T1::accumulator_type)(end[-1]);
outpen.put_value((typename T2::value_type)(tot*divisor));
}
outpen.dec_y(y);
}
}
#else
template<typename T1,typename T2> void
vbox_blur(T1 pen,int w, int h, int length,T2 outpen)
{
int x,y;
typename T1::iterator_y iter, end, biter,eiter;
//print out the info I need to figure out if this is somehow a buffer overrun...
/*char *beginptr=0,*endptr=0;
{
T1 ypen = pen;
T1 endpen = pen;
endpen.move(w,h);
ypen.inc_y();
T2 open = outpen,
oepen = outpen;
oepen.move(w,h);
printf("V Blur (%d,%d,s-%d) in(%p,%p,st %d) out(%p,%p)\n",
w,h,length,(char*)pen.x(),(char*)endpen.x(),(char*)ypen.x()-(char*)pen.x(),
(char*)open.x(),(char*)oepen.x());
}*/
length=min(h-1,length);
const float divisor(1.0f/(length*2+1));
//const int div = (length*2+1);
//since the filter range is 2*length+1 we need h-1
for(x=0;x<w;x++,pen.inc_x(),outpen.inc_x())
{
iter=pen.y();
end=pen.end_y();
const typename T1::value_type bval = *iter;
const typename T1::value_type eval = end[-1];
typename T1::accumulator_type tot(bval*(length+1));
//beginptr = (char*)&*iter; endptr = (char*)&*end;
//printf("\nx line %d (%p,%p)\n",x,beginptr,endptr);
//printf("Init %.3f - ",tot);
for (y=0;y<length && iter!=end;y++)
{
tot+=iter[y];
//printf("(%d,%p,+%.3f->%.3f),",y,&iter[y],iter[y],tot);
}
iter=pen.y();
//printf(" tot=%.3f\n",tot);
biter = iter+(-length-1); //get the first one...
eiter = iter+length;
//y will always be > length
//T2 open = outpen;
for (y=0;y<h && iter!=end;y++,++iter,++biter,++eiter,outpen.inc_y())
{
//printf("y line %d - (%f) ",y,tot);
if (y>length)
{
typename T1::value_type &v = *biter;
/*if( (char*)&v < beginptr ||
(char*)&v >= endptr)
printf("crap! %d (%p off %p)\n",y,(char*)&v,(char*)&*iter);*/
tot -= v;
//printf("[%.3f,",v);
}
else
{
tot -= bval;
//printf("[%.3f,",bval);
}
if (y+length<h)
{
typename T1::value_type &v = *eiter;
/*if( (char*)&v < beginptr ||
(char*)&v >= endptr)
printf("crap! %d (%p off %p)\n",y,(char*)&v,(char*)&*iter);*/
tot += v;
//printf("%.3f]",v);
}
else
{
tot += eval;
//printf("%.3f]",eval);
}
//test handled in the previous case...
//tot -= (y>length) ? *biter : bval;
//tot += (y+length<h) ? *eiter : eval;
//printf(" - %.3f\n",tot);
outpen.put_value(tot*divisor);
}
outpen.dec_y(y);
}
}
#endif
template<typename T1,typename T2> void
box_blur(T1 pen,int w, int h, int blur_w, int blur_h, T2 outpen)
{ hbox_blur(pen,w,h,blur_w,outpen); vbox_blur(pen,w,h,blur_h,outpen); }
template<typename T1,typename T2> void
box_blur(T1 pen,int w, int h, int size, T2 outpen)
{ hbox_blur(pen,w,h,size,outpen); vbox_blur(pen,w,h,size,outpen); }
template<typename T1,typename T2> void
hbox_blur(T1 begin,T1 end, int len,T2 outpen)
{
typename T1::difference_type size(end-begin);
hbox_blur(begin,size.x,size.y,len,outpen);
}
template<typename T1,typename T2> void
vbox_blur(T1 begin,T1 end, int len,T2 outpen)
{
typename T1::difference_type size(end-begin);
vbox_blur(begin,size.x,size.y,len,outpen);
}
template<typename T1,typename T2> void
box_blur(T1 begin,T1 end, int blur_w, int blur_h,T2 outpen)
{
typename T1::difference_type size(end-begin);
hbox_blur(begin,size.x,size.y,blur_w,outpen); vbox_blur(begin,size.x,size.y,blur_h,outpen);
}
template<typename T1,typename T2> void
box_blur(T1 begin,T1 end, int blursize,T2 outpen)
{
typename T1::difference_type size(end-begin);
hbox_blur(begin,size.x,size.y,blursize,outpen); vbox_blur(begin,size.x,size.y,blursize,outpen);
}
};
/* === E X T E R N S ======================================================= */
/* === E N D =============================================================== */
#endif