Aegisub/subprojects/iconv/libiconv/ucs2.h
2021-01-10 03:14:12 -05:00

68 lines
2.2 KiB
C

/*
* Copyright (C) 1999-2001, 2008 Free Software Foundation, Inc.
* This file is part of the GNU LIBICONV Library.
*
* The GNU LIBICONV Library is free software; you can redistribute it
* and/or modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* The GNU LIBICONV Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with the GNU LIBICONV Library; see the file COPYING.LIB.
* If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
* Fifth Floor, Boston, MA 02110-1301, USA.
*/
/*
* UCS-2
*/
/* Here we accept FFFE/FEFF marks as endianness indicators everywhere
in the stream, not just at the beginning. The default is big-endian. */
/* The state is 0 if big-endian, 1 if little-endian. */
static int
ucs2_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
{
state_t state = conv->istate;
int count = 0;
for (; n >= 2;) {
ucs4_t wc = (state ? s[0] + (s[1] << 8) : (s[0] << 8) + s[1]);
s += 2; n -= 2; count += 2;
if (wc == 0xfeff) {
} else if (wc == 0xfffe) {
state ^= 1;
} else if (wc >= 0xd800 && wc < 0xe000) {
conv->istate = state;
return RET_SHIFT_ILSEQ(count);
} else {
*pwc = wc;
conv->istate = state;
return count;
}
}
conv->istate = state;
return RET_TOOFEW(count);
}
/* But we output UCS-2 in big-endian order, without byte-order mark. */
/* RFC 2152 says:
"ISO/IEC 10646-1:1993(E) specifies that when characters the UCS-2 form are
serialized as octets, that the most significant octet appear first." */
static int
ucs2_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
{
if (wc < 0x10000 && wc != 0xfffe && !(wc >= 0xd800 && wc < 0xe000)) {
if (n >= 2) {
r[0] = (unsigned char) (wc >> 8);
r[1] = (unsigned char) wc;
return 2;
} else
return RET_TOOSMALL;
} else
return RET_ILUNI;
}