Re: gEDA-user: pcb layer groups

[DJ Delorie <dj@xxxxxxxxxxx>]

> It's slow even without it.

I checked out your board.  You have 24 overlapping polygons forming a
single contiguous ground plane, and your "thermals" all mostly at odd
(i.e. not 45 or 90) angles.  Try using a single polygon for the ground
plane, and for SMD thermals try using short traces parallel to the
axes (0/90/180/270 degrees) coming out of the center of the pad's
edges.  I tried just replacing your polygons with a single one and it
was a bit faster, but not nearly as fast as thindraw.

Hmmm... I wonder if we could add a "this poly is a rectangle" flag
(internally) and speed this up a bit?  I suspect the big time use is
in the masked layer copy, though.  To do clearances, we first create a
mask, draw all the clearances to the mask, then use that mask to draw
the polygons.  This appears to be an inherently slow operation.  Yet
another case where "hide polygons" would be a useful option.

You should try using thindraw for boards like this, too.  It's a LOT
faster, and you'd notice that you have two sets of thermals that
aren't on pads.