LeOS-Genesis/external/badvpn/misc/Utf8Encoder.h

82 lines
2.8 KiB
C

/**
* @file Utf8Encoder.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef BADVPN_UTF8ENCODER_H
#define BADVPN_UTF8ENCODER_H
#include <stdint.h>
/**
* Encodes a Unicode character into a sequence of bytes according to UTF-8.
*
* @param ch Unicode character to encode
* @param out will receive the encoded bytes. Must have space for 4 bytes.
* @return number of bytes written, 0-4, with 0 meaning the character cannot
* be encoded
*/
static int Utf8Encoder_EncodeCharacter (uint32_t ch, uint8_t *out);
int Utf8Encoder_EncodeCharacter (uint32_t ch, uint8_t *out)
{
if (ch <= UINT32_C(0x007F)) {
out[0] = ch;
return 1;
}
if (ch <= UINT32_C(0x07FF)) {
out[0] = (0xC0 | (ch >> 6));
out[1] = (0x80 | ((ch >> 0) & 0x3F));
return 2;
}
if (ch <= UINT32_C(0xFFFF)) {
// surrogates
if (ch >= UINT32_C(0xD800) && ch <= UINT32_C(0xDFFF)) {
return 0;
}
out[0] = (0xE0 | (ch >> 12));
out[1] = (0x80 | ((ch >> 6) & 0x3F));
out[2] = (0x80 | ((ch >> 0) & 0x3F));
return 3;
}
if (ch < UINT32_C(0x10FFFF)) {
out[0] = (0xF0 | (ch >> 18));
out[1] = (0x80 | ((ch >> 12) & 0x3F));
out[2] = (0x80 | ((ch >> 6) & 0x3F));
out[3] = (0x80 | ((ch >> 0) & 0x3F));
return 4;
}
return 0;
}
#endif