/* Determine display width of Unicode character.

   Copyright (C) 2001-2002, 2006-2025 Free Software Foundation, Inc.

   Written by Bruno Haible <bruno@clisp.org>, 2002.

   This file 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 2.1 of the

   License, or (at your option) any later version.

   This file 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 <https://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */

#include "uniwidth.h"

#include "cjk.h"

/* The non-spacing attribute table consists of:

   * Non-spacing characters; generated from PropList.txt or

     "grep '^[^;]*;[^;]*;[^;]*;[^;]*;NSM;' UnicodeData.txt"

   * Format control characters; generated from

     "grep '^[^;]*;[^;]*;Cf;' UnicodeData.txt"

   * Zero width characters; generated from

     "grep '^[^;]*;ZERO WIDTH ' UnicodeData.txt"

   * Hangul Jamo characters that have conjoining behaviour:

       - jungseong = syllable-middle vowels

       - jongseong = syllable-final consonants

     Rationale:

     1) These characters act like combining characters. They have no

     equivalent in legacy character sets. Therefore the EastAsianWidth.txt

     file does not really matter for them; UAX #11 East Asian Width

     <https://www.unicode.org/reports/tr11/> makes it clear that it focus

     is on compatibility with traditional Japanese layout.

     By contrast, the same glyphs without conjoining behaviour are available

     in the U+3130..U+318F block, and these characters are mapped to legacy

     character sets, and traditional Japanese layout matters for them.

     2) glibc does the same thing, see

     <https://sourceware.org/bugzilla/show_bug.cgi?id=21750>

     <https://sourceware.org/bugzilla/show_bug.cgi?id=26120>

 */

#include "uniwidth/width0.h"

#include "uniwidth/width2.h"

#include "unictype/bitmap.h"

#define SIZEOF(a) (sizeof(a) / sizeof(a[0]))

/* Determine number of column positions required for UC.  */

int

uc_width (ucs4_t uc, const char *encoding)

{

  /* Test for non-spacing or control character.  */

  if ((uc >> 9) < SIZEOF (nonspacing_table_ind))

    {

      int ind = nonspacing_table_ind[uc >> 9];

      if (ind >= 0)

        if ((nonspacing_table_data[64*ind + ((uc >> 3) & 63)] >> (uc & 7)) & 1)

          {

            if (uc > 0 && uc < 0xa0)

              return -1;

            else

              return 0;

          }

    }

  else if ((uc >> 9) == (0xe0000 >> 9))

    {

      if (uc >= 0xe0100)

        {

          if (uc <= 0xe01ef)

            return 0;

        }

      else

        {

          if (uc >= 0xe0020 ? uc <= 0xe007f : uc == 0xe0001)

            return 0;

        }

    }

  /* Test for double-width character.  */

  if (bitmap_lookup (&u_width2, uc))

    return 2;

  /* In ancient CJK encodings, Cyrillic and most other characters are

     double-width as well.  */

  if (uc >= 0x00A1 && uc < 0xFF61 && uc != 0x20A9

      && is_cjk_encoding (encoding))

    return 2;

  return 1;

}