We can't get all the way there because we can't create pads outside
of modules and the Gerbers don't store any grouping/footprint info.
This change moves us from outputing a via for every flashed item
(some of which don't even have holes) to synthesizing pads from
flashed items using a via (when they have holes) and a copper polygon.
This is much better for SMD pads, perhaps better for regular pads,
and no worse for vias.
2) Change from legacy Cu stack to counting down from top=(F_Cu or 0).
The old Cu stack required knowing the count of Cu layers to make
sense of the layer number when converting to many exported file types.
The new Cu stack is more commonly used, although ours still gives
B_Cu a fixed number.
3) Introduce class LSET and enum LAYER_ID.
4) Change *.kicad_pcb file format version to 4 from 3.
5) Change fixed names Inner1_Cu-Inner14_Cu to In1_Cu-In30_Cu and their
meanings are typically flipped.
6) Moved the #define LAYER_N_* stuff into legacy_plugin.cpp where they
can die a quiet death, and switch to enum LAYER_ID symbols throughout.
7) Removed the LEGACY_PLUGIN::Save() and FootprintSave() functions.
You will need to convert to the format immediately, *.kicad_pcb and
*.kicad_mod (=pretty) since legacy format was never going to know
about 32 Cu layers and additional technical layers and the reversed Cu
stack.
Should allow Pcbnew code easier to change and Gerbview code more understandable and easier to maintain.
Code cleaning (remove dead code, add comments).
Minor other enhancements.
Peter Montgomery
Jeff Young
jean-pierre charras
Jon Evans
Wayne Stambaugh
Dick Hollenbeck
Lorenzo Marcantonio