blob: c09867e0670d26a88d55442c3aaafe1fc5848674 (
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
|
/* Run-time scaletable computation for Xcftools
*
* Copyright (C) 2006 Henning Makholm
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "pixels.h"
#ifndef PRECOMPUTED_SCALETABLE
uint8_t scaletable[256][256] ;
int ok_scaletable = 0 ;
void
mk_scaletable(void)
{
unsigned p, q, r ;
if( ok_scaletable ) return ;
for( p = 0 ; p < 128 ; p++ )
for( q = 0 ; q <= p ; q++ ) {
r = (p*q+127)/255 ;
scaletable[p][q] = scaletable[q][p] = r ;
scaletable[255-p][q] = scaletable[q][255-p] = q-r ;
scaletable[p][255-q] = scaletable[255-q][p] = p-r ;
scaletable[255-p][255-q] = scaletable[255-q][255-p] = (255-q)-(p-r) ;
}
ok_scaletable = 1 ;
}
#endif
|
