Glossary of used terms

There is 2 kind of closed polylines :

closed polyline : a polyline whose first and last vertex are different. It is created using the CLOSE option of the PLINE command. It has the "Closed" flag set on.

unopen polyline : a polyline whose first and last vertex are identical. It is created by clicking the first vertex of the polyline to close it. It has the "Closed" flag set off.

Visually, these 2 polylines are identical, but the "unopen" one has 1 vertex more than the "truly" closed one.

Temporary mark : a color square identifying a specific point of a polyline (a vertex or a clicked point), or an arrow, showing the polyline direction. This square is removed when you issue a Zoom, Pan or Redraw command. See program options.

Choice of the part of a polyline to process : during certain commands on closed polylines, you will have to choose which part of the polyline must be processed. Indeed, when a polyline is closed, there are 2 ways to walk through it : a temporary polyline will show a possible solution, click the left button of the mouse to switch to the other possible solution, or click the right button to validate.

Select the part to process using the mouse button.