kicad-developers team mailing list archive

[Lorenzo Marcantonio <l.marcantonio@xxxxxxxxxxxx>]

On Fri, May 03, 2013 at 05:31:48PM +0200, Miguel Angel Ajo wrote:
> I like your idea Adam, specially because you can change file for a stringio, and it could work..
> 
>     Lorenzo, what do you think?,  
> 
>     do you like Adam refactor idea for the plot controller?
> 
>    I think it's important that we have similar interfaces at both sides, and also that we have a drill controller (hehe, my implicit meaning was more for Adam that for you) but if it's good if anyone gets it done.

I suppose the stringio is something like a strstream... as I explained
in the previous message it's not so trivial. To have a better idea of
the issue behind this look at GERBER_PLOTTER::EndPlot,
PDF_PLOTTER::EndPlot and PDF_PLOTTER::closePdfStream. In fact the PDF
writer keeps open *two* files during plotting.

As I already said you *could* rework everything to use something else
instead of FILE* (like a wxMemoryOutputStream), but you'd need to wait
anyway for the end of the plot. So just use a temporary file and slurp
it (or mmap it, if possible) at the end. I think that the performance
improvement is not worth the lot of work needed (also I don't know how
to use wx streams:D). Maybe it's because I worked on mainframes but
I like temporary files... You're free to do it if you want, it could be an
interesting project (for someone else than me:P)

As for the drill controller: there are more or less four phases:
- Acquiring and sorting all the drills (no I/O, lot of data structures
  working)
- Outputting the actual drill file(s)
- Outputting the drill map(s) (this would be done using the plotters)
- Outputting the drill report

The tricky thing is handling NPTH and blind/buried; I don't know is
everything is already implemented (at a cursory look it seems so)
because I never used blind or buried vias. Anyway the output should
consist of (both of these both as excellon and drill map):
- NPTH holes (the last drilling/milling pass)
- THT holes (usual holes for 2 side boards)
- Blind holes from top to each layer
- Blind holes from bottom to each layer
- Buried vias between adjacent layers

I don't know if a function to customize each of these name would be
useful; I'd vote no if asked (blind and burieds usually need a human
operator on the fabrication side *and* you'll have to decide with him
beforehand the board stacking).

A somewhat useful function would be merging the NPTH and THT in one
single drill tape (like pcbnew did before NPTH holes), since some
fabricator require it (they then split the tape depending on the copper
beneath).

-- 
Lorenzo Marcantonio
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