utf16.c

Go to the documentation of this file.

// SPDX-FileCopyrightText: 2017 kazarmy <kazarmy@gmail.com>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_types.h>
#include <rz_util.h>
 
/* Convert an UTF-16 buf into a unicode RzRune */
RZ_API int rz_utf16_decode(const ut8 *ptr, int ptrlen, RzRune *ch, bool bigendian) {
    if (ptrlen < 1) {
        return 0;
    }
    int high = bigendian ? 0 : 1;
    int low = bigendian ? 1 : 0;
    if (ptrlen > 3 && (ptr[high] & 0xdc) == 0xd8 && (ptr[high + 2] & 0xdc) == 0xdc) {
        if (ch) {
            *ch = ((ptr[high] & 3) << 24 | ptr[low] << 16 | (ptr[high + 2] & 3) << 8 | ptr[low + 2]) + 0x10000;
        }
        return 4;
    }
    if (ptrlen > 1 && ptr[high]) {
        if (ch) {
            *ch = ptr[high] << 8 | ptr[low];
        }
        return 2;
    }
    if (ptrlen > 1) {
        if (ch) {
            *ch = (ut32)ptr[low];
        }
        return 1;
    }
    return 0;
}
 
/* Convert an UTF-16LE buf into a unicode RzRune */
RZ_API int rz_utf16le_decode(const ut8 *ptr, int ptrlen, RzRune *ch) {
    return rz_utf16_decode(ptr, ptrlen, ch, false);
}
 
/* Convert an UTF-16BE buf into a unicode RzRune */
RZ_API int rz_utf16be_decode(const ut8 *ptr, int ptrlen, RzRune *ch) {
    return rz_utf16_decode(ptr, ptrlen, ch, true);
}
 
/* Convert a unicode RzRune into a UTF-16LE buf */
RZ_API int rz_utf16le_encode(ut8 *ptr, RzRune ch) {
    if (ch < 0x10000) {
        ptr[0] = ch & 0xff;
        ptr[1] = ch >> 8 & 0xff;
        return 2;
    }
    if (ch < 0x110000) {
        ch -= 0x10000;
        RzRune high = 0xd800 + (ch >> 10 & 0x3ff);
        RzRune low = 0xdc00 + (ch & 0x3ff);
        ptr[0] = high & 0xff;
        ptr[1] = high >> 8 & 0xff;
        ptr[2] = low & 0xff;
        ptr[3] = low >> 8 & 0xff;
        return 4;
    }
    return 0;
}