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2024-02-13 13:37:55 -06:00

30 lines
740 B
C

/*
* Encode a single code point as UTF-8.
*/
#include "defs.h"
#include "misc.h"
size_t encode_utf8(void *output, unsigned long ch)
{
unsigned char *start = (unsigned char *)output, *p = start;
if (ch < 0x80) {
*p++ = ch;
} else if (ch < 0x800) {
*p++ = 0xC0 | (ch >> 6);
*p++ = 0x80 | (ch & 0x3F);
} else if (ch < 0x10000) {
*p++ = 0xE0 | (ch >> 12);
*p++ = 0x80 | ((ch >> 6) & 0x3F);
*p++ = 0x80 | (ch & 0x3F);
} else {
assert(ch <= 0x10FFFF);
*p++ = 0xF0 | (ch >> 18);
*p++ = 0x80 | ((ch >> 12) & 0x3F);
*p++ = 0x80 | ((ch >> 6) & 0x3F);
*p++ = 0x80 | (ch & 0x3F);
}
return p - start;
}