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From: jwhitnell@cup.portal.com (Jerry D Whitnell)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Rolling your own 32-bit offscreen pixmaps -- magic incantat
Message-ID: <32082@cup.portal.com>
Date: 26 Jul 90 01:33:04 GMT
References: <1990Jul23.203843.2380@efi.com>
Organization: The Portal System (TM)
Lines: 22

Tim writes...
|So, I made changes as recommended, including such annoyances as creating
|an empty color table.  Problem is, after some intensive debugging effort,
|peeking at all the fields of the CGrafPort, GDevice, and PixMapHandle
|with Lightsbug, and going over my code with a fine-toothed comb, I still
|crash during the initial EraseRect.  Is there some magic wand I have to
|wave to get a 32-bit offscreen pixmap to work?

Funny, I could have written this messages a couple of weeks ago.  Can you
tell me (via email if necessary) what you are doing?  


A couple of things to check:  the pixelType, pixelSize, cmdCount and cmpSize
fields in the PixMap.  For 32-bit PixMaps, they should be chunky, 32, 3 and 8.
Also check the gdType field in the graphics device, it should be direct RGB,
not CLUT.  If you have a 24-bit color monitor, you might compare a 32-bit
color window with your offscreen PixMap, and comfirm the differences.

Hope this helps.

Jerry Whitnell
SuperMac Technology