/* Determine display width of UTF-16 string.
   Copyright (C) 2001-2002, 2006-2007, 2009-2018 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2002.

   This program 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.

   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
   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 "unistr.h"

int
u16_width (const uint16_t *s, size_t n, const char *encoding)
{
  const uint16_t *s_end = s + n;
  int width = 0;

  while (s < s_end)
    {
      ucs4_t uc;
      int w;

      s += u16_mbtouc_unsafe (&uc, s, s_end - s);

      if (uc == 0)
        break; /* end of string reached */

      w = uc_width (uc, encoding);
      if (w >= 0) /* ignore control characters in the string */
        width += w;
    }

  return width;
}
