This splits the tool into two separate tools: by center and
by even gaps. Previously, this was automatically decided, based on
if the items could have any gaps between them. This was unintuitive
as it would appear to arrange by centre point sometimes but not others.
When items aren't all the same width, the results can then be very
different, based only on the starting positions.
The new behaviour is to have a dedicated tool for each, which echos
how graphical programs like Inkscape manage this.
The by-gaps method is then extended to work for overlapping items
(when items overlap, the overlaps are made equal). The logic is
centralised in kimath/geometry, and some QA is added. This should
make it easier to extend to eeschema, for example.
This also (attempts to) address some rounding issues which could
cause minor, but compounding, errors to build up along the list
of items.
Also, fix bugs in the collection filtering - previously items
like markers were filtered out only after the selection size
was used to compute the gaps between items.
The last segment of a track could be removed when the iterator does not
correctly loop. Keeping the ll within bounds and checking for
equivalency instead of comparison works for last point
The clearance between two zones could be rather slow. This was in part
to trying to do triangle-triangle collisions between zones when we only
need outline collision and in part to the shape_line_chain collision
routine. The shape_line_chain collisions don't need to recreate
segments on each iteration and should instead create them once and using
this to check all collisions
Fixes https://gitlab.com/kicad/code/kicad/-/issues/17327
Previously the snap points computed for oval pads didn't get all the
points correct. This breaks out the "find snap points for ovals"
into a function, reworks the logic, adds some tests.
Also adds "extremum points" when the oval isn't exactly H/V.
Fixes: https://gitlab.com/kicad/code/kicad/-/issues/15594
Using the new ITEM_MODIFICATION_ROUTINE system, drop in two new
tools: chamfer and line extend. These are two geometric operations
that are relatively common when editing footprints in particular.
Chamfer delegates the geometric calculations to a dedicated unit
in kimath/geometry.