Re: [artworks] Sprite masks and hidden sprites

  • From: Martin Wuerthner <lists@xxxxxxxxxxxxxxx>
  • To: artworks@xxxxxxxxxxxxx
  • Date: Mon, 12 May 2008 21:36:28 +0200

In message <cfdb649e4f.tim@xxxxxxxxxxxxxxxxxxxxx>
          Tim Powys-Lybbe <tim@xxxxxxxxx> wrote:
> In message of 12 May, Tim Powys-Lybbe <tim@xxxxxxxxx> wrote:

>> First the finished artwork looks fine.  Most of the sprites have masks
>> which are used to give transparent backgrounds to them.  But some,
>> which definitely have these transparent bits, do not print them out
>> correctly but show them as squares of white on the paper.  I have
>> repeated this to ensure that I was using sprites with transparent
>> masks and it still happened. Any ideas?

Here, you mentioned printing whereas further down you referred to PDF 
export. You probably want to use PDF export in this case, which 
handles masked sprites fine. However, if you were to print a sprite 
with a mask then please bear in mind that the RISC OS PostScript 
printer driver ignores the mask! This is one of the things that a 
PostScript 3 driver would finally cope with.

> I have now found that GView gets the image right - so I can rely on PDF
> export.

Yes, definitely. Apart from a few exotic things PDF export handles 
everything ArtWorks supports.

> But !PDF makes a right mess of the sprites with transparent
> areas: in particular it shows up all the original gubbins that was
> 'deleted' by areas of transparency.

You really need to check things in GView, which you eventually did. 
Whenever transparency is involved you cannot rely on !PDF (though I 
thought it handled masked sprites correctly).

> I thought I could make it a bit better by changing all the transparent
> areas to white and then back to transparent, thus getting rid of the
> gubbins.  Then, I though, it would be easy to replace the sprite in
> the sprite pool and see what effect this had on !PDF.

> But it is not possible to replace sprites in the sprite pool.  Or I
> can't see anything in the manuals.  So I will have to delete all uses of
> each offending sprite and replace each one individually, a mere 79 items
> to deal with.  Does anyone know of an easier way to update sprites in
> the sprite pool?

Unfortunately not. This is one of the things on the wish list. 
Technically, it would be fairly easy to replace a sprite in the sprite 
pool by an edited version with the same number of pixels and the same 
colour depth without having to touch the main document but there is no 
user interface to do so.

>> Second I find I have a few sprites in the sprite pool that I cannot
>> see on the artwork and yet when I try to delete them fromt he sprite
>> pool, I am told they are in use.

That means that they are still lurking somewhere. For instance, you 
could have two versions of a sprite, one on top of the other in the 
document. Then, you cannot see the bottom one. There is no mechanism 
to find a specific sprite in the document and I cannot really think of 
how the user interface for that should look like.

Martin Wuerthner           MW Software          lists@xxxxxxxxxxxxxxx
    To change, suspend or cancel your subscription go to

Other related posts: