[ptx] multy tiff output

[Edouard Gomez]

emmanuelfavrenicolin at free.fr (emmanuelfavrenicolin at free.fr) wrote:
> there used to be a patch for enblend 1.3 that allowed to work with multi layer
> tiff. Unfortunenatly the developper(s ?) didn't care about it and the following
> version 2.0 was released without it. The person that did this patch for version
> 1.3 didn't do one for later version maybe because does not want to loose is
> time for "nothing" scared that it wouldn't be integrated again!

I'm this person,  and i would just  like to say that i  didn't port this
patch  because now  patch for  enblend 1.3  doesn't fit  anymore  in the
enblend 2.0 design because it uses the vigra library.

My patch wa doing 2 different things:
 - allow the mask function to properly work with offseted images because
   multi layer tiff relies on this feature.
 - add a layer of abstraction  where enblend functions were dealing with
   "source pages" instead of TIFF files. This allows creating pages from
   a same file, and so a multilayered TIFF file.
   Basically something like:
   struct imgPage
   {
     char *filename;
     int layer_id;
   }
   which could be extended to
   struct imgPage
   {
     char *filename; // gives the name of the file holding the data
     enum  supportedType type; //  Tells the  type of  the file,  for
                               // handling correctly the image loading
     void *type_related_data; // Private data pointer to hold special
                              // data keeping trace of important things
                              // to retrieve "the page" from the file.
    }

Sadly these  two ideas cannot be  integrated in vigra  that easily. I've
never been scared or whatsoever...  I just feel my ideas are outdated in
current enblend design.  Hope the  upstream author finds a good idea for
integrating back multilayered tiff support.

-- 
Edouard Gomez