Divides area into sub-areas using lines
I'm looking for a simple way to divide an area into smaller areas, using lines as dividers. A basic way to do this is to select both the lines and the parent area, then right-click and select the Crop submenu command to split the area against the lines.
But here's the catch: The lines I'm using originate in a draw program, and any "islands" import to Global Mapper as unclosed lines. Any attempt to import "islands" separately as areas just adds another array of complications.
I've looked into other possibilities suggested in the past on this Forum (such as https://www.globalmapperforum.com/discussion/12052/create-area-features-from-existing-line-and-area-features ) but none gives a simple, clean operation in which new areas are created from lines (the way you would color areas in a coloring book).
QGIS has a tool called "Polygonize" which seems to do this....but who wants to use Q when Global Mapper is so much easier? http://confound.me.uk/maps/ppv4.pdf
Is there some obscure tool in Global that I've missed? Or procedure?