#include "utf8.h"

int
codepoint_to_utf8(Eina_Unicode g, char *txt)
{
   if (g < (1 << (7)))
     { // 0xxxxxxx
        txt[0] = g & 0x7f;
        txt[1] = 0;
        return 1;
     }
   else if (g < (1 << (5 + 6)))
     { // 110xxxxx 10xxxxxx
        txt[0] = 0xc0 | ((g >> 6) & 0x1f);
        txt[1] = 0x80 | ((g     ) & 0x3f);
        txt[2] = 0;
        return 2;
     }
   else if (g < (1 << (4 + 6 + 6)))
     { // 1110xxxx 10xxxxxx 10xxxxxx
        txt[0] = 0xe0 | ((g >> 12) & 0x0f);
        txt[1] = 0x80 | ((g >> 6 ) & 0x3f);
        txt[2] = 0x80 | ((g      ) & 0x3f);
        txt[3] = 0;
        return 3;
     }
   else if (g < (1 << (3 + 6 + 6 + 6)))
     { // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
        txt[0] = 0xf0 | ((g >> 18) & 0x07);
        txt[1] = 0x80 | ((g >> 12) & 0x3f);
        txt[2] = 0x80 | ((g >> 6 ) & 0x3f);
        txt[3] = 0x80 | ((g      ) & 0x3f);
        txt[4] = 0;
        return 4;
     }
   else if (g < (1 << (2 + 6 + 6 + 6 + 6)))
     { // 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
        txt[0] = 0xf8 | ((g >> 24) & 0x03);
        txt[1] = 0x80 | ((g >> 18) & 0x3f);
        txt[2] = 0x80 | ((g >> 12) & 0x3f);
        txt[3] = 0x80 | ((g >> 6 ) & 0x3f);
        txt[4] = 0x80 | ((g      ) & 0x3f);
        txt[5] = 0;
        return 5;
     }
   else if ((unsigned int)g < (unsigned int)(1 << (1 + 6 + 6 + 6 + 6 + 6)))
     { // 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
        txt[0] = 0xfc | ((g >> 30) & 0x01);
        txt[1] = 0x80 | ((g >> 24) & 0x3f);
        txt[2] = 0x80 | ((g >> 18) & 0x3f);
        txt[3] = 0x80 | ((g >> 12) & 0x3f);
        txt[4] = 0x80 | ((g >> 6 ) & 0x3f);
        txt[5] = 0x80 | ((g      ) & 0x3f);
        txt[6]  = 0;
        return 6;
     }
   else
     { // error - cant encode this in utf8
        txt[0] = 0;
        return 0;
     }
}