libunic/charsize.c

/* This software is licensed by the MIT License, see LICENSE file */
/*                                Copyright © 2022 Gregory Lirent */

#include "build.h"

int charsize(const char* s) {

    unsigned int v;
    if (*(unsigned char*)s <= 0x7f)
        return 1;

    memcpy(&v, s, 4);

    if (IS_LITTLE_ENDIAN) {
        if ((v&0x0000c0e0) == 0x000080c0) return 2;
        if ((v&0xc0c0c0f8) == 0x808080f0) return 4;
        if ((v&0x00c0c0f0) == 0x008080e0) return 3;
    } else {
        if ((v&0xe0c00000) == 0xc0800000) return 2;
        if ((v&0xf8c0c0c0) == 0xf0808080) return 4;
        if ((v&0xf0c0c000) == 0xe0808000) return 3;
    }
    return 0;
}