kicad-developers team mailing list archive

[Wayne Stambaugh <stambaughw@xxxxxxxxx>]

What is wrong with just reading the footprint in mm rather than
converting from decimils from now on?  It's only going to be a one time
issue when a user adds a footprint that has not been converted to mm to
a board.

On 11/22/2017 06:16 AM, Oliver Walters wrote:
> Wayne,
> 
> 
> I believe he has a point. The footprint files do not have version
> information so if you load and save a footprint multiple times, the
> "offset" (if non zero) will continuously be multiplied by 2.54x
> 
> I think there are two ways forward:
> 
> 1. Revert my patch and live with the file format unit inconsistency
> 2. I can provide a patch for my original idea of writing "offset"
> instead of "at". We make a clean break and "at" is legacy and always
> read as inches. "offset" is new and is mm.
> 
> Let me know what you want to do.
> 
> Thanks,
> Oliver
> 
> On Wed, Nov 22, 2017 at 8:25 PM, easyw <easyw@xxxxxxxxxxxx
> <mailto:easyw@xxxxxxxxxxxx>> wrote:
> 
>     Hi Wayne,
> 
>         I'm not sure I understand what the issue is.  Once an offset is
>         changed
>         to mm when either a footprint in a board or a library is parsed, why
>         would it not be saved as mm.  If it isn't, then this is a bug. 
>         Once the
>         footprint offset is converted to mm, there should be no
>         expectation that
>         it will be correct for older versions of KiCad.  Is there
>         something else
>         at play here?
> 
> 
>     this issue is related to the footprint editor...
> 
>     1) The fp exporter button exports correctly the footprint with
>     offset in mm
>     2) The fp importer button imports always reading the data as
>     deci-mils and multiplies it internally
>     3) To fix this issue the patch needs to manage the footprint
>     importer code to read the values in mm instead of deci-mils.
> 
>         What if you open the same file again, how can it tell it's in mm
>         or inches?
> 
>     @Jose ... this is an issue already addressed...
>     The decision to change offset values to mm will break previous
>     footprints that have non zero offset.
>     But I think this has been considered a 'small' disturb for users
>     when the patch has been committed, as stated in a previous mail:
> 
>         This is not a big issue because the only effects the footprints
>         embedded
>         in the board.  Users with custom footprint libraries that contain 3D
>         model offsets will just have to fix the offsets.  I'm guessing
>         this is a
>         fairly small number of users.
> 
>     https://lists.launchpad.net/kicad-developers/msg31589.html
>     <https://lists.launchpad.net/kicad-developers/msg31589.html>
> 
>     M
> 
> 
>     On 11/22/2017 2:19 AM, Wayne Stambaugh wrote:
> 
>         I'm not sure I understand what the issue is.  Once an offset is
>         changed
>         to mm when either a footprint in a board or a library is parsed, why
>         would it not be saved as mm.  If it isn't, then this is a bug. 
>         Once the
>         footprint offset is converted to mm, there should be no
>         expectation that
>         it will be correct for older versions of KiCad.  Is there
>         something else
>         at play here?
> 
>         On 11/21/2017 04:26 PM, Oliver Walters wrote:
> 
>             Wayne,
> 
>             Not sure how you want to handle this but I feel that making
>             a clean
>             break and using "offset" for mm solves all the issues
>             associated with
>             embedded footprints without version info, as Maurice says
>             above. Let me
>             know if want me to implement.
> 
>             On Wed, Nov 22, 2017 at 8:24 AM, easyw <easyw@xxxxxxxxxxxx
>             <mailto:easyw@xxxxxxxxxxxx>
>             <mailto:easyw@xxxxxxxxxxxx <mailto:easyw@xxxxxxxxxxxx>>> wrote:
> 
>                  Hi,
>                  first headache symptom...
> 
>                  Testing conditions:
>                  latest KiCad patched
>                  Application: pcbnew
>                  Version: (2017-11-21 revision 8de70f3)-master, release
>             build
> 
>                  If you edit a footprint adding 3D models offset and
>             then export it,
>                  it will be saved with the new mm convention...
>                  but when re-imported it will be read with deci-mils and
>             displayed
>                  with wrong convention...
>                  Moreover if the imported footprint will be inserted
>             into the board,
>                  the footprint will conserve the wrong values...
>                  Those wrong values will be then saved with the new
>             kicad_pcb board....
> 
> 
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