lib/unictype/mirror.c

   1 /* Mirrored Unicode characters.
   2    Copyright (C) 2002, 2006, 2009-2018 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2002.
   4
   5    This program is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Lesser General Public License as published
   7    by the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include "unictype.h"
  22
  23 /* Define u_mirror table.  */
  24 #include "mirror.h"
  25
  26 bool
  27 uc_mirror_char (ucs4_t uc, ucs4_t *puc)
  28 {
  29   unsigned int index1 = uc >> mirror_header_0;
  30   if (index1 < mirror_header_1)
  31     {
  32       int lookup1 = u_mirror.level1[index1];
  33       if (lookup1 >= 0)
  34         {
  35           unsigned int index2 = (uc >> mirror_header_2) & mirror_header_3;
  36           int lookup2 = u_mirror.level2[lookup1 + index2];
  37           if (lookup2 >= 0)
  38             {
  39               unsigned int index3 = (uc & mirror_header_4);
  40               int lookup3 = u_mirror.level3[lookup2 + index3];
  41
  42               *puc = uc + lookup3;
  43               return (lookup3 != 0);
  44             }
  45         }
  46     }
  47   *puc = uc;
  48   return false;
  49 }