kicad-developers team mailing list archive

[Dick Hollenbeck <dick@...>]

> ** the first copper layer is number 0 but has a special name 'front', in 
> addition to any name the user gives it.
Clarification: each copper layer has both a user given name, and a 
layer number, just as now. The reserved token 'front' and 'back' are 
simply "special layer numbers", not actually in the same name space as 
layer names.

After declaring the layers up front in the file, throughout the board we 
will use layer numbers rather than layer names. However, rather than 
becoming too dependent on the layer count, which changes the numeric 
value of the back of the board, we will use 'back' in certain situations 
in place of the layer number for back. Likewise for front, it is a 
layer number, not a layer name per se.

We saw an example of this a few postings ago:

(layers front back) # a LAYERSET object which includes only the front 
and back copper layers.

(layers front 1 back ) # I suppose this has to be legal also



Techical layers:

In the case of technical layers, I would be inclined to not expose nor 
support any "user defined technical layer names". This is as now. But 
in the board file, I would chose to use a fixed special token to these 
special layers similar to 'front' and 'back'.

examples: soldp_fr, soldp_bk, silks_fr, silks_bk.

These special tokens are treated like layer numbers.

This way the board never becomes dependent on layer numbers other than 
copper layer numbers.

Scream now if this hurts, nod if it seems reasonable.


Dick