kicad-developers team mailing list archive

[Oliver Walters <oliver.henry.walters@xxxxxxxxx>]

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> 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
>
> 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>> 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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