1/* Conversion UCS-4 to UTF-16.
2   Copyright (C) 2002, 2006-2007, 2009-2010 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 <http://www.gnu.org/licenses/>.  */
17
18#include <config.h>
19
20/* Specification.  */
21#include "unistr.h"
22
23int
24u16_uctomb_aux (uint16_t *s, ucs4_t uc, int n)
25{
26  if (uc < 0xd800)
27    {
28      /* The case n >= 1 is already handled by the caller.  */
29    }
30  else if (uc < 0x10000)
31    {
32      if (uc >= 0xe000)
33        {
34          if (n >= 1)
35            {
36              s[0] = uc;
37              return 1;
38            }
39        }
40      else
41        return -1;
42    }
43  else
44    {
45      if (uc < 0x110000)
46        {
47          if (n >= 2)
48            {
49              s[0] = 0xd800 + ((uc - 0x10000) >> 10);
50              s[1] = 0xdc00 + ((uc - 0x10000) & 0x3ff);
51              return 2;
52            }
53        }
54      else
55        return -1;
56    }
57  return -2;
58}
59