- /*
- int row = p >> 1;
- const float *rowptr = m + row * 4;
-
- if((p & 1) == 0) {
- res->x = m[12] + rowptr[0];
- res->y = m[13] + rowptr[1];
- res->z = m[14] + rowptr[2];
- res->w = m[15] + rowptr[3];
- } else {
- res->x = m[12] - rowptr[0];
- res->y = m[13] - rowptr[1];
- res->z = m[14] - rowptr[2];
- res->w = m[15] - rowptr[3];
- }
- */