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From: dplatt@coherent.com (Dave Platt)
Newsgroups: comp.sys.mac.programmer
Subject: Re: PaletteManager vs. CopyBits (long; gurus only)
Keywords: Palette Manager, CopyBits, Custom Search Procedure
Message-ID: <47531@improper.coherent.com>
Date: 23 Feb 90 00:46:15 GMT
References: <10713@zodiac.ADS.COM> <1919@wrgate.WR.TEK.COM>
Reply-To: dplatt@coherent.com (Dave Platt)
Distribution: na
Organization: Coherent Thought Inc., Palo Alto CA
Lines: 37

In article <1919@wrgate.WR.TEK.COM> herbw@midas.WR.TEK.COM (Herb Weiner) writes:
> In Article <10713@zodiac.ADS.COM> jdevries@zodiac.ADS.COM (Jeff De Vries) writes:
>
> > 3)  How do you use CopyBits with an animated palette?
>  
> In my opinion, Apple screwed up badly on this one.  To make it work, you need
> to implement a custom search procedure.  If your window is active (you have
> received an Activate Event, but have not received a deactivate event), You
> need to install it immediately before you do your CopyBits, and you need to
> remove it immediately after your CopyBits.  (If you do all this, you do not
> need to worry about the client ID, because your CopyBits is the only possible
> client.)

There's a much better way to do this if you have 32-bit Color QuickDraw
installed.  You can tag your off-screen PixMap so that [a] it uses the
same palette as the window, and [b] the values in the PixMap represent
palette indices, NOT colortable indices.  When you CopyBits() the
off-screen PixMap to the screen, CopyBits performs a palette-index-to
colortable-index lookup, and stores the correct [animated or non-
animated] color into the screen PixMap.  This lookup takes the place of
the usual colortable-index->RGBcolor->screen-colortable-index search...
which will not handle animated colors properly.

This feature works very well even if your destination window touches
multiple screens.  It's VERY hard to CopyBits() animated colors to a
multi-screen window with any other technique... and every other technique
I've tried or encountered is UGLY!
  
> Refer to Inside Mac Volume V for more info on all this.

Also the 32-bit Color QuickDraw documentation, available from APDA or on
Phil&Dave's Excellent but Generally Unavailable CD-ROM.
-- 
Dave Platt                                             VOICE: (415) 493-8805
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