Path: utzoo!censor!geac!jtsv16!uunet!brunix!iris.brown.edu!ejd
From: ejd@iris.brown.edu (Ed Devinney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: PICT2
Message-ID: <15891@brunix.UUCP>
Date: 21 Sep 89 23:13:12 GMT
References: <3084@ur-cc.UUCP>
Distribution: usa
Organization: IRIS/Brown University
Lines: 36

In article <3084@ur-cc.UUCP> tonyg@merlin.cvs.rochester.edu (Tony 
Giaccone) writes:
> So if that's the case why doesn't the copybits install a copy of the
> current color table into the PICT2. Or, if it does how come PICTViewer
> doesn't use that Color Table when it displays the file? It certainly seems
> to use the color tables in other PICT2 files. I don't get it. 

   If you use something like PictDetective*, you should see that CopyBits() 
does put a copy of the ColorTable into the PICT.  This Table, though, will 
not assert its colors in the GDevice when you _draw_ the pict.  The Table 
is used only as the source table when CopyBits does its color mapping on pict 
playback.   

   I would bet that the reason that PICTViewer seems to use the ColorTable 
for other PICTs is that the colors in them may be closer to the default 
palette and don't get mapped too badly.  

   What you probably want to do is to write or find a PICT-viewing program 
that allows import of Palettes as well as PICTs (tho' I don't know of any 
offhand); when writing your files you could also write a Palette resource, 
for instance.

   In sum, the PICT does hold a copy of the ColorTable.  The ColorTable 
will be used by CopyBits() to map your PixMap's colors to those in the 
GDevice.  The ColorTable currently in the GDevice will _not_ be affected 
by the ColorTable in your PixMap.  It is the job of the displaying 
application to determine the appropriate Palette needed to display the 
PICT correctly, and to cause its Window to assert that Palette.

ed - Former Junior Rocket Scientist for Color @ Cricket Software (RIP)

[*PictDetective is a product of Palomar Software]
++++++
ed devinney...IRIS/Brown University, Providence, RI...ejd@iris.brown.edu
-- There's a light on the hill, that's far out in the distance,
   ...it calls out my name, it calls out for a change...(Fishbone) --