ref: 8f1bc269f071e2e5eb607ecb26133656fc850527
dir: /DoConfig/fltk/src/xutf8/lcUniConv/utf8.h/
/* $XFree86: xc/lib/X11/lcUniConv/utf8.h,v 1.3 2000/11/28 18:50:07 dawes Exp $ */
/*
* UTF-8
*/
/* Specification: RFC 2279 */
static int
utf8_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
{
unsigned char c = s[0];
if (c < 0x80) {
*pwc = c;
return 1;
} else if (c < 0xc2) {
return RET_ILSEQ;
} else if (c < 0xe0) {
if (n < 2)
return RET_TOOFEW(0);
if (!((s[1] ^ 0x80) < 0x40))
return RET_ILSEQ;
*pwc = ((ucs4_t) (c & 0x1f) << 6)
| (ucs4_t) (s[1] ^ 0x80);
return 2;
} else if (c < 0xf0) {
if (n < 3)
return RET_TOOFEW(0);
if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
&& (c >= 0xe1 || s[1] >= 0xa0)))
return RET_ILSEQ;
*pwc = ((ucs4_t) (c & 0x0f) << 12)
| ((ucs4_t) (s[1] ^ 0x80) << 6)
| (ucs4_t) (s[2] ^ 0x80);
return 3;
} else if (c < 0xf8) {
if (n < 4)
return RET_TOOFEW(0);
if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
&& (s[3] ^ 0x80) < 0x40
&& (c >= 0xf1 || s[1] >= 0x90)))
return RET_ILSEQ;
*pwc = ((ucs4_t) (c & 0x07) << 18)
| ((ucs4_t) (s[1] ^ 0x80) << 12)
| ((ucs4_t) (s[2] ^ 0x80) << 6)
| (ucs4_t) (s[3] ^ 0x80);
return 4;
} else if (c < 0xfc) {
if (n < 5)
return RET_TOOFEW(0);
if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
&& (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
&& (c >= 0xf9 || s[1] >= 0x88)))
return RET_ILSEQ;
*pwc = ((ucs4_t) (c & 0x03) << 24)
| ((ucs4_t) (s[1] ^ 0x80) << 18)
| ((ucs4_t) (s[2] ^ 0x80) << 12)
| ((ucs4_t) (s[3] ^ 0x80) << 6)
| (ucs4_t) (s[4] ^ 0x80);
return 5;
} else if (c < 0xfe) {
if (n < 6)
return RET_TOOFEW(0);
if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
&& (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
&& (s[5] ^ 0x80) < 0x40
&& (c >= 0xfd || s[1] >= 0x84)))
return RET_ILSEQ;
*pwc = ((ucs4_t) (c & 0x01) << 30)
| ((ucs4_t) (s[1] ^ 0x80) << 24)
| ((ucs4_t) (s[2] ^ 0x80) << 18)
| ((ucs4_t) (s[3] ^ 0x80) << 12)
| ((ucs4_t) (s[4] ^ 0x80) << 6)
| (ucs4_t) (s[5] ^ 0x80);
return 6;
} else
return RET_ILSEQ;
}
static int
utf8_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n) /* n == 0 is acceptable */
{
int count;
if (wc < 0x80)
count = 1;
else if (wc < 0x800)
count = 2;
else if (wc < 0x10000)
count = 3;
else if (wc < 0x200000)
count = 4;
else if (wc < 0x4000000)
count = 5;
else if (wc <= 0x7fffffff)
count = 6;
else
return RET_ILSEQ;
if (n < count)
return RET_TOOSMALL;
switch (count) { /* note: code falls through cases! */
case 6: r[5] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x4000000;
case 5: r[4] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x200000;
case 4: r[3] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x10000;
case 3: r[2] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x800;
case 2: r[1] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0xc0;
case 1: r[0] = wc;
}
return count;
}