lepton/geda diffs: C (Re: sym to verilog-ams)

Felix:
> On Tue, Apr 05, 2022 at 12:24:11PM +0200, [email protected] wrote:
> > So, what is really the goal (for both sym and sch files) ?
> > Is it:
...
> > A, "diff orig_file round_trip_file | wc -c" == 0
> > B, sort files by some program and there will be no diffs
> > C, converting files to jpg's and they they don't show any differences
> > D, the netlists produced with alt. orig/round_trip produces no diff
> > E, something else
...
> > For C, there is lepton-schdiff/schdiff.
> 
> I like the idea. Are we there yet? When you try, you will find
> non-cosmetical issues with nets that need to be addressed.

lepton-schdiff makes pngs of the files to compare and
lets imagemagic to show the diffs in some vay:

VIEWER="display"
...
lepton-cli export -f png -s 1344px:1008px --no-color -F "${font}" -o $RIGHTPNG $RIGHTFILE && \
lepton-cli export -f png -s 1344px:1008px --no-color -F "${font}" -o $LEFTPNG  $LEFTFILE  && \
composite -stereo 0 $LEFTPNG $RIGHTPNG $DIFFPNG && \
$VIEWER $DIFFPNG
...

schdiff does the same.
Don't know how to see the stereo though...

One could probably use something other than stereo in composite.

Lilypond uses something similar in their regression tests:
 https://lilypond.org/doc/v2.21/Documentation/contributor/introduction-to-regression-tests
 https://gitlab.com/lilypond/lilypond/-/blob/master/scripts/auxiliar/make-regtest-pngs.sh

Regards,
/Karl Hammar