> Current state: > One physicaly connected surface is called "layer group". > What is called "layer" is something that one can work on > and will end up in some surface "layer group". > There are special "Layers" called silk, ratlines, mask, outline,.. > > Proposed state: > I think it is common to call "layer" one electricaly > connected sufrace. Cannot we come up with some other > name for "layer", so we can leave "layer" for one electricaly > connected surface?
We've discussed this before, came up with something like "drawing sheet" vs "physical layer". > If there are more (ie. silk) layers, where to put the silk > layer of an footprint? Should we somehow link cooper > layer and silk layer? What if we link more than one silk > layer to cooper layer? Aside from numbering layers from 1 .. N, there are symbolic names for "top", "inner", and "bottom" layers. Footprints use symbols names, they're mapped to numeric layers as appropriate for each board. That doesn't mean footprints *can't* use numeric layers, but they're more reusable if they don't. Each drawing layer has a record of which physical layer it corresponds to (if at all), so you could (for example) assign a silk layer to one of your internal layers, despite that not making sense. However, assigning a documentation layer to an inner layer *might* make sense. > Or do we want to have some "default" silk and cooper layer and move > all footprints from that one to desired one? The stackup needs to understand the concept of inner and outer layers at least, so it can map a library footprint to a specific element. Of course, I leave open what "outer layer" means, esp in the context of flex cables where a given layer might be an inner layer over here, and an outer layer over there... > One of the problems someone wants to solve is to be able to put > "outline" of an footprint to one silk layer and "refdef" to another. Again, we need to have some way of mapping a well-known set of symbolic names to specific physical layers. For text, perhaps we adopt gschem's named attribute method? So we have some text *named* refdes, with *value* of "R4", that happens to be on layer "topsilk:refdes" - it looks for a "topsilk:refdes" mapping rule, and if it doesn't find one, looks for a "topsilk" mapping rule, etc. _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
