On 20.01.2015 17:58, Wayne Stambaugh wrote: > On 1/20/2015 10:51 AM, Tomasz Wlostowski wrote: >> On 20.01.2015 16:19, Wayne Stambaugh wrote: >>> On 1/20/2015 12:44 AM, LordBlick wrote: >>>> In response to a message written on 13.01.2015, 19:20, from Tomasz >>>> Wlostowski: >>>>> Hi all, >>>>> >>>>> During my work on diff pairs/matched length tools, I've encountered a >>>>> rather tricky problem: as the diff pair gap specific to a particular >>>>> pair of traces is stored nowhere, the shove algorithm will mess up DP >>>>> coupling after saving and re-loading the board. Ergo: the DP gaps (and >>>>> possibly other settings) need to be stored somewhere in .kicad_pcb >>>>> files. Perhaps in a yet another s-expr token. >>>>> >>>>> The problem is that adding any new token to the file format causes all >>>>> precedent versions of pcbnew to drop an error attempting to load the >>>>> file. I would propose two solutions to overcome this: >>>>> - (a dumb one) if the version in the file header is newer than the >>>>> version supported by the running application, issue warnings instead of >>>>> fatal errors on unknown tokens, >>>>> - (a bit smarter) enclose all optional tokens in a "minimum" version >>>>> block ( min_version version_number ( optional_token ( ... ) ) ) that >>>>> would be ignored if the application version < version_number. >>>>> >>>>> I consider this modification quite important from the point of view of >>>>> adding future features and the upcoming stable version: if we keep >>>>> things as they are, adding any new feature will either make the files >>>>> unreadable to the stable version or force us to support saving in >>>>> multiple format versions. >>>>> >>>>> Looking forward to your feedback, >>>>> Tom >>>> I think that may be sufficient to add section [gal] to .pro file as >>>> usual project setting. In this way you can avoid the next .kicad_pcb >>>> format version change. >>>> >>> >>> I'm not terribly thrilled about that idea. One of the things we have >>> changed over the years is to move board specific settings out of the >>> project file and into the board file. This makes the board file more >>> portable. >> >> Hi Wayne, >> >> Fully agree here. What I meant when I started this thread was defining a >> way to store more complex DRC constraints than simple clearance/track >> width. The current model can't handle differential pair and constrained >> trace length. Such parameters surely belong to a PCB design, so their >> place is IMHO in the .kicad_pcb file. >> >> Anyway, for the first release of the new P&S features, I'm not going to >> modify the file format. >> >> Cheers, >> Tom >> > > Hey Tom, > > If it is important to save the design settings, now would be the time to > make any file changes rather than after the stable release. We know we > are already going to have issues with users who upgrade from the current > stable release due to layer name translations and the 32 to 64 layer > transition. I would rather get it over with now than drag it out over > the next development cycle.
Hi Wayne, I meant the merge of diff pairs into product branch, so that people could already test and profit from the new features. I hope we'll have the time to define and implement file format upgrades before the stable release goes out. Cheers, Tom _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : kicad-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp