1 // Copyright 2004 David Hilvert <dhilvert@auricle.dyndns.org>,
2 // <dhilvert@ugcs.caltech.edu>
4 /* This file is part of the Anti-Lamenessing Engine.
6 The Anti-Lamenessing Engine is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 The Anti-Lamenessing Engine is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with the Anti-Lamenessing Engine; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #ifndef __triangle_h__
22 #define __triangle_h__
25 * A triangle filter class.
28 class triangle
: public filter
{
35 double _triangle(ale_pos p
) const {
36 if (fabs(p
) >= half_width
)
39 return (1 - fabs(p
) / half_width
);
42 double _triangle(point p
) const {
43 return _triangle(p
[0]) * _triangle(p
[1]);
49 * Size of filter support, in number of half-cycles to each side of the
52 virtual ale_real
support() const {
56 virtual int equals(const filter
*f
) const {
57 if (typeid(*f
) == typeid(*this))
58 return ((triangle
*)f
)->half_width
== half_width
;
63 * Response of filter at point p
65 virtual ale_real
response(point p
) const {
69 triangle(ale_real half_width
) {
70 this->half_width
= half_width
;