blob: 84b13bd21e9e7ca89cb9f85d12fff74e2baa145a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
/*************************************************************************
* Copyright (C) 2010 Tavian Barnes <tavianator@tavianator.com> *
* *
* This file is part of The Dimension Library. *
* *
* The Dimension Library is free software; you can redistribute it and/ *
* or modify it under the terms of the GNU Lesser General Public License *
* as published by the Free Software Foundation; either version 3 of the *
* License, or (at your option) any later version. *
* *
* The Dimension Library 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 *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this program. If not, see *
* <http://www.gnu.org/licenses/>. *
*************************************************************************/
/**
* @file
* Checker pattern.
*/
#include "dimension.h"
/** Checker pattern callback. */
static double
dmnsn_checker_pattern_fn(const dmnsn_pattern *checker, dmnsn_vector v)
{
double xmod = fmod(v.x, 2.0);
double ymod = fmod(v.y, 2.0);
double zmod = fmod(v.z, 2.0);
if (xmod < -dmnsn_epsilon)
xmod += 2.0;
if (ymod < -dmnsn_epsilon)
ymod += 2.0;
if (zmod < -dmnsn_epsilon)
zmod += 2.0;
/* Return 0 when an even number of coordinates are in [0, 1), 1 otherwise */
unsigned int n = 0;
if (xmod >= 1.0)
++n;
if (ymod >= 1.0)
++n;
if (zmod >= 1.0)
++n;
return (n%2 == 0) ? 0.0 : 1.0;
}
dmnsn_pattern *
dmnsn_new_checker_pattern(void)
{
dmnsn_pattern *checker = dmnsn_new_pattern();
checker->pattern_fn = dmnsn_checker_pattern_fn;
return checker;
}
|
