Mission Editor -> DRAW Tool. Allow 'Joining' LINE SEGMENTS to form a complex polygon.

[TEMPEST.114]

As title says.

If the last control point is very close to the first control point, then join them up automatically and convert into a complex polygon.

The great feature of using LINE SEGMENTS is that you don't have to hold the LHMB down and you can zoom/pan the map before laying addition control points (this should be default on ALL drawing tools to be honest - it would radically improve the FREE POLYGON tool).