    switch(tet_index)
    {
        case 0:
            ret.index0 = 8;
            ret.index1 = 9;
            ret.index2 = 0;
            ret.index3 = 1;
            break;
        case 1:
            ret.index0 = 8;
            ret.index1 = 9;
            ret.index2 = 1;
            ret.index3 = 5;
            break;
        case 2:
            ret.index0 = 8;
            ret.index1 = 9;
            ret.index2 = 5;
            ret.index3 = 4;
            break;
        case 3:
            ret.index0 = 8;
            ret.index1 = 9;
            ret.index2 = 4;
            ret.index3 = 0;
            break;
        case 4:
            ret.index0 = 8;
            ret.index1 = 10;
            ret.index2 = 2;
            ret.index3 = 3;
            break;
        case 5:
            ret.index0 = 8;
            ret.index1 = 10;
            ret.index2 = 3;
            ret.index3 = 7;
            break;
        case 6:
            ret.index0 = 8;
            ret.index1 = 10;
            ret.index2 = 7;
            ret.index3 = 6;
            break;
        case 7:
            ret.index0 = 8;
            ret.index1 = 10;
            ret.index2 = 6;
            ret.index3 = 2;
            break;
        case 8:
            ret.index0 = 8;
            ret.index1 = 11;
            ret.index2 = 3;
            ret.index3 = 0;
            break;
        case 9:
            ret.index0 = 8;
            ret.index1 = 11;
            ret.index2 = 0;
            ret.index3 = 4;
            break;
        case 10:
            ret.index0 = 8;
            ret.index1 = 11;
            ret.index2 = 4;
            ret.index3 = 7;
            break;
        case 11:
            ret.index0 = 8;
            ret.index1 = 11;
            ret.index2 = 7;
            ret.index3 = 3;
            break;
        case 12:
            ret.index0 = 8;
            ret.index1 = 12;
            ret.index2 = 1;
            ret.index3 = 2;
            break;
        case 13:
            ret.index0 = 8;
            ret.index1 = 12;
            ret.index2 = 2;
            ret.index3 = 6;
            break;
        case 14:
            ret.index0 = 8;
            ret.index1 = 12;
            ret.index2 = 6;
            ret.index3 = 5;
            break;
        case 15:
            ret.index0 = 8;
            ret.index1 = 12;
            ret.index2 = 5;
            ret.index3 = 1;
            break;
        case 16:
            ret.index0 = 8;
            ret.index1 = 13;
            ret.index2 = 1;
            ret.index3 = 0;
            break;
        case 17:
            ret.index0 = 8;
            ret.index1 = 13;
            ret.index2 = 0;
            ret.index3 = 3;
            break;
        case 18:
            ret.index0 = 8;
            ret.index1 = 13;
            ret.index2 = 3;
            ret.index3 = 2;
            break;
        case 19:
            ret.index0 = 8;
            ret.index1 = 13;
            ret.index2 = 2;
            ret.index3 = 1;
            break;
        case 20:
            ret.index0 = 8;
            ret.index1 = 14;
            ret.index2 = 5;
            ret.index3 = 6;
            break;
        case 21:
            ret.index0 = 8;
            ret.index1 = 14;
            ret.index2 = 6;
            ret.index3 = 7;
            break;
        case 22:
            ret.index0 = 8;
            ret.index1 = 14;
            ret.index2 = 7;
            ret.index3 = 4;
            break;
        case 23:
            ret.index0 = 8;
            ret.index1 = 14;
            ret.index2 = 4;
            ret.index3 = 5;
            break;    
    }