Moves forced-transparency setting down into VIEW_ITEM so that it can
be used to place forced-transparent objects in a different target.
This keeps EnableDepthTest() from equalizing the alpha values between
the two symbols (or two footprints).
If the pad hasn't already been owned by another zone, and the zone we're
currently filling can connect to it, then we want to try to flash it even
if it's not connected to anything else.
Fixes https://gitlab.com/kicad/code/kicad/issues/13415
Rather than moving the netname around, we want to keep the correct
number of netnames on a track such that there is always at least one
displayed on long tracks even when panning.
This reduces calculation time while keeping the netnames visible
Fixes https://gitlab.com/kicad/code/kicad/issues/12436
1) The highest priority zone that a via/pad collides with "owns" its
connectivity state. Once set, lower priority zones cannot change it --
and in fact, if they would have connected to it are forced not to.
2) The connectivity state goes with the zone fill state, and therefore
must be saved in the file.
3) Display of remove-unconnected's pads is no longer done in GetViewLOD()
(which isn't called for selected items), and is instead done in PCB_PAINTER.
This allows us to draw the full pad in outline mode when a via/pad is
selected which would otherwise only show the hole.
4) Note that in some cases this will still generate DRC errors -- in
particular when a via nearly collides with a higher priority zone it
won't get "owned" by that zone and may therefore have insufficient
clearance if said zone concludes it's unconnected and a subsequent
(lower priority) zone connects to it (causing it to now become flashed).
Fixes https://gitlab.com/kicad/code/kicad/issues/11299
(This is for the move tool, not DRC. DRC uses more sophisticated keepout
processing which is too slow for the move tool, and doesn't let us know which
keepout area collided for collision highlighting.)
Fixes https://gitlab.com/kicad/code/kicad/issues/12594
1) Move a bunch of std::map's to std::unordered_map to get constant-time
look-ups
2) Lengthen progress-reporting intervals to spend more time doing work
and less time talking about it
3) Reverse order of SHAPE_LINE_CHAINs in thermal intersection checks to
make (much) better use of bbox caches
4) Don't re-generate bboxes we already have
5) Fix some autos that weren't by reference (and were therefore copying
large datasets)
6) Rename delta progressDelta so it's easier to search for in future
7) Get rid of a few more autos (because I don't like them)
8) Pass large items to lambdas by reference
Fixes https://gitlab.com/kicad/code/kicad/issues/12130