1/* Conversion UCS-4 to UTF-16.
2   Copyright (C) 2002 Free Software Foundation, Inc.
3   Written by Bruno Haible <haible@clisp.cons.org>, 2002.
4
5This program is free software; you can redistribute it and/or modify
6it under the terms of the GNU General Public License as published by
7the Free Software Foundation; either version 2, or (at your option)
8any later version.
9
10This program is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this program; if not, write to the Free Software
17Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
18
19
20#include <stddef.h>
21
22/* Return the length (number of units) of the UTF-16 representation of uc,
23   after storing it at S.  Return -1 upon failure, -2 if the number of
24   available units, N, is too small.  */
25static int
26u16_uctomb_aux (unsigned short *s, unsigned int uc, int n)
27{
28  if (uc >= 0x10000)
29    {
30      if (uc < 0x110000)
31	{
32	  if (n >= 2)
33	    {
34	      s[0] = 0xd800 + ((uc - 0x10000) >> 10);
35	      s[1] = 0xdc00 + ((uc - 0x10000) & 0x3ff);
36	      return 2;
37	    }
38	}
39      else
40	return -1;
41    }
42  return -2;
43}
44
45static inline int
46u16_uctomb (unsigned short *s, unsigned int uc, int n)
47{
48  if (uc < 0x10000 && n > 0)
49    {
50      s[0] = uc;
51      return 1;
52    }
53  else
54    return u16_uctomb_aux (s, uc, n);
55}
56