[CREATE] [OpenRaster] improve interpretation of layer group offsets

[Andrew Chadwick]

Might be acceptable if *nothing* writes those with anything other than
zero. MyPaint doesn't write them, and it doesn't look as though the
GIMP guys want to either, for cross-application compatibility reasons
☺

However it would be backwards-incompatible in terms of the spec. I'd
want to go through at least one minor revision (the Y in X.Y.Z) where
it's deprecated first, and flag it for removal at 1.0.0.

(Picky semver stuff.)


On 11 January 2016 at 11:22, Boudewijn Rempt <boud at valdyas.org> wrote:
> Hm... I'm pretty sure that the original intention never was to make the
> layers inside a group have coordinates relative to the group layer's
> x,y coordinates. Moving a group in Krita just moves the contained layers.
>
> So, I would simply amend this to "groups don't have x,y coordinates".
>
>
>
> On Mon, 11 Jan 2016, Andrew Chadwick wrote:
>
>> There is some confusion in the GIMP bug tracker about how OpenRaster
>> layer stack offsets apply:
>>
>> https://bugzilla.gnome.org/show_bug.cgi?id=760348
>>
>> Do we need some clarifying language in
>>
>> https://wiki.freedesktop.org/www/Specifications/OpenRaster/Draft/LayersStack/
>> ?
>>
>>
>> I propose:
>>
>> ---------------8< -----------------
>>
>> x and y attributes
>>
>> These attributes define the offset of the layer or stack relative to
>> its parent. These are signed integers with a default value of 0. These
>> attributes must not be set on the root stack element: the root stack
>> has zero offset.
>>
>> The offset of a layer or a stack must be calculated relative to the
>> calculated offset of its parent stack. For the example above, the
>> "OpenRaster Logo" layer has coordinates (x=15, y=5) in the image's
>> coordinate system.
>>
>> The X axis is oriented from left to right, and the Y axis is oriented
>> downwards.
>>
>> --------------->8 -----------------
>>
>> It's probably worth having a para about Y having the usual computer
>> graphic interpretation too, so I added that.
>>
>>
>> --
>> Andrew Chadwick
>> _______________________________________________
>> CREATE mailing list
>> CREATE at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/create
>
>
> --
> Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org



-- 
Andrew Chadwick