diff options
Diffstat (limited to 'kernel/kls_xcf/xcf2pnm/scaletab.c')
| -rw-r--r-- | kernel/kls_xcf/xcf2pnm/scaletab.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/kernel/kls_xcf/xcf2pnm/scaletab.c b/kernel/kls_xcf/xcf2pnm/scaletab.c new file mode 100644 index 0000000..c09867e --- /dev/null +++ b/kernel/kls_xcf/xcf2pnm/scaletab.c @@ -0,0 +1,42 @@ +/* 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 + |