/* Horror stories: http://en.wikipedia.org/wiki/UTF-16 */#include "tagspriv.h" #define rchr(s) (be ? ((s)[0]<<8 | (s)[1]) : ((s)[1]<<8 | (s)[0])) static const uint8_t mark[] = {0x00, 0x00, 0xc0, 0xe0, 0xf0}; intutf16to8(uint8_t *o, int osz, const uint8_t *s, int sz){	uint32_t c, c2;	int i, wr, j;	bool be; 	i = 0;	be = true;	if(s[0] == 0xfe && s[1] == 0xff)		i += 2;	else if(s[0] == 0xff && s[1] == 0xfe){		be = false;		i += 2;	} 	for(; i < sz-1 && osz > 1;){		c = rchr(&s[i]);		i += 2;		if(c >= 0xd800 && c <= 0xdbff && i < sz-1){			c2 = rchr(&s[i]);			if(c2 >= 0xdc00 && c2 <= 0xdfff){				c = 0x10000 | (c - 0xd800)<<10 | (c2 - 0xdc00);				i += 2;			}else				return -1;		}else if(c >= 0xdc00 && c <= 0xdfff)			return -1; 		if(c < 0x80)			wr = 1;		else if(c < 0x800)			wr = 2;		else if(c < 0x10000)			wr = 3;		else			wr = 4; 		osz -= wr;		if(osz < 1)			break; 		o += wr;		for(j = wr; j > 1; j--){			*(--o) = (c & 0xbf) | 0x80;			c >>= 6;		}		*(--o) = (uint8_t)c | mark[wr];		o += wr;	} 	*o = 0;	return i;}