ale/d2/render/psf/box.h
2022-07-30 14:46:04 -03:00

83 lines
2.3 KiB
C++

// Copyright 2003 David Hilvert <dhilvert@auricle.dyndns.org>,
// <dhilvert@ugcs.caltech.edu>
/* This file is part of the Anti-Lamenessing Engine.
The Anti-Lamenessing Engine 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 Anti-Lamenessing Engine 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 Anti-Lamenessing Engine; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __psf_box_h__
#define __psf_box_h__
#include "../../point.h"
#include "psf.h"
/*
* Point-spread function module.
*
* This module implements the box filter.
*/
class box : public psf {
ale_real _radius;
public:
/*
* The following four functions indicate filter boundaries. Filter
* support may include everything up to and including the boundaries
* specified here.
*/
ale_real min_i() const { return -_radius; }
ale_real max_i() const { return _radius; }
ale_real min_j() const { return -_radius; }
ale_real max_j() const { return _radius; }
/*
* Response function
*
* Get the response to the rectangle bounded by (top, bot, lef, rig).
* This function must correctly handle points which fall outside of the
* filter support. The variety the responding pixel is provided, in
* case response is not uniform for all pixels (e.g. some sensor arrays
* stagger red, green, and blue sensors).
*/
psf_result operator()(ale_real top, ale_real bot, ale_real lef, ale_real rig,
unsigned int variety) const {
psf_result result;
if (top < min_i())
top = min_i();
if (bot > max_i())
bot = max_i();
if (lef < min_j())
lef = min_j();
if (rig > max_j())
rig = max_j();
if (bot > top && rig > lef)
for (int k = 0; k < 3; k++)
result.matrix(k, k) = (bot - top) * (rig - lef) / (4 * _radius * _radius);
return result;
}
box(ale_real radius) {
_radius = radius;
}
};
#endif