Cut out objects by lists

The mode is based on use of lists of objects.

After activation of a mode the operator is offered to specify, which of earlier created lists is necessary to use as etalon list, and which - as the edited list.

The etalon list should contain objects (only polygon objects) which contour will be used for editing objects of the edited list.

Objects from the etalon list are not edited (except for a case when the insert into etalon object of points of crossing with edited object is made).

Processing begins after pressing of Ok button.

Example of mode use.

It is necessary to provide a correct relative positioning of objects of type: Wood, sparse growth of trees, Garden, etc. with objects of type Lake, Pond etc.

I.e. lakes inside a wood - only in glades, with an external contour - only the touch, intersection (imposing) is not allowed.

In this case the list of objects such as "Lake" (etalon) and the list of objects such as "Wood" (edited) is created.

The approximate result of processing of such lists is submitted on the figure.

In case the lake was completely inside a wood, by its contour the subobject will be created. If in this place a subobject already was, and it precisely coincides with a contour of processed lake, additional subobject will not be created.

In case the lake intersects one or the several already existing subobjects, the uniting (expansion) of glades will be made.

In case the lake intersects an external contour of a wood, the coordination of a wood border by border of lake will be made, into a contour of lake the vertexes of intersection with a contour of a wood will be added.