| Type | Integer |
| 0 | |
| Description | It designates where the initial point of a vector is taken to a lattice point. I paint it as the terminal of a vector agrees with a lattice point if it is+1; I paint it as the initial point of a vector agrees with a lattice point if it is-1; that I paint as the midpoint of a vector agrees with a lattice point if it is 0 |