-
-The original code was highlighting pins/pads only when a short came around
-after rats nest optimization. This was not very helpful on a complex board.
-There had been a long discussion on the mailing list about the best solutions.
-There were a few very good ideas, including:
-
-
manual tagging of objects (lines, polys, arcs, vias) with net and warn
- where two differently tagged net connects
-
automatic tagging based on "where it was connected first", then the same
- warning mechanism as above
-
trace history (using the undo buffer?) and go back until when it was
- not broken, check what exactly broke it
-
history combined with tagging
-
calculate minimal cut
-
-
-I choose minimal cut for my patch because it doesn't require tracing the
-full history or any manual administration of nets vs. objects (which I
-would find inevitable even with manual tagging - directly or indirectly
-the user needs to be able to change net tags).
-
-The minimal cut is the least amount of object whose removal would resolve
-the short. It is best demonstrated on an example:
-
-
-
-Removing all the marked lines/polys/vias would surely resolve the short
-(sometimes leaving rat lines behind). Minimal cut is better than randomly
-removing objects, tho: it guarantees that the minimal amount of objects
-are to be removed. On a complex board, this place is likely to be close
-to the place where the problem really is - much closer than the pins/pads.
-
-Since mincut can be expensive on large boards, the feature can be enabled
-per board (a new PCB flag) and can be disabled globally (--enable-mincut 0
-when starting PCB).
-
-
save/load and compatibility
-New PCB flag enablemincut. Mainline pcb ignores this flag but does not
-preserve it.
-
-
![[pcb-rnd logo]](../resources/logo32.png){kind=logo}
-![[Six simple layouts, one correct and five with shorted nets]](mincut.png)
-