[crossfire] Arch repository: layered art files?

[Mark Wedel]

David Delbecq wrote:
> En l'instant précis du 14/12/07 06:20, Mark Wedel s'exprimait en ces
> termes:
>> Fair enough.  But suppose someone checks something in using adobe photoshop 
>> format, and a month later I want to change the image, but don't have photoshop.
>>
>>   Is it OK then for me to remove the original (source) photoshop image and just 
>> have a PNG?  Even if the original author is still around, maybe he doesn't have 
>> time to make the change in the near future.
>>   
> Well, you can't open the photoshop file, you remake a file using,
> example, gimp and commit png, gimp, remove photoshop.
> The source is now gimp. If the final file is similar to original one and
> original author wants to restart from his photoshop file, fair engouh.
> He retrieve it from the svn history, manipulate it and commit this: new
> png, removed gimp, new photoshop. As i said, to the opposite of cvs, svn
> does handle properly deletions. Original file is still available in history.

  Ok - I have no problem with that being the method used.  People will just need 
to make sure they svn delete the source file - otherwise there is real risk of 
someone seeing the source file and overwriting the modified png.  OTOH, the 
changes lost are those that the folks who wrote the png made, so there is real 
incentive for them to make sure they remove that source file - it is their 
changes being lost, not someone else.

>>   And gimp's .xcf files are another odd case here.  Pretty much every linux 
>> distro will have gimp, but folks using windows or mac would need to download it. 
>>   Should it be considered proper that the mac/windows person download gimp and 
>> update the .xcf file, or is it ok for them to just write out a png and remove 
>> the .xcf source?
>>   
> It's probably less work for them to download the xcf / edit / save as
> png then open png in photoshop, extract elements, remakes some layers,
> save both.

  Not sure I understand your explanation.  Wouldn't it be less work for them to 
just open the PNG in photoshop, and not deal with the xcf files at all?



> I think the main question is "do we comply to GPL to the point we must
> give *all* sources, including those of our png? If yes, then if someone
> modify something with an obscure program, he must commit the source too :/

The meaning of a 'source' for an image is somewhat misleading.  For one, it is 
hard to prove that there even is a source (someone could be using some basic 
image manipulation program that just reads and writes pngs and doesn't have any 
meaningful native format).  This has been the case - certainly when mass changes 
have been done (like xbm -> xpm -> png conversion, as well as 24x24->32x32 
conversion, things like netpbm have been used).

  But I also use the term meaningful format here, because I think that is relevant.

  There are lots of good examples why having xcf data could be useful - if the 
layers are separate, can manipulate those to different images, etc.

  However, there are also lots of cases where having the xcf image may really 
not be useful.  For example, if I take an image and it needs some cosmetic 
changes, I'm not likely to do that on a layer, I'm likely to do that on the base 
image itself.  All the xcf image would get the next developer is potential to 
undo the changes from within gimp (I think gimp saves the undo history, but not 
sure).  Is it really worthwhile then to have the xcf then?  I'd say probably not.