Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!yale!eagle.wesleyan.edu!rcook
From: rcook@eagle.wesleyan.edu
Newsgroups: comp.sys.mac.programmer
Subject: What's the screen depth?
Message-ID: <1991Mar28.110336.40826@eagle.wesleyan.edu>
Date: 28 Mar 91 16:03:36 GMT
Organization: Wesleyan University
Lines: 27

Here's the deal:  I have an old style window (ie not color, a standard
grafport) and I do some color drawing in it with standard QuickDraw colors
(by setting ForeColor and BackColor)  This works fine on a machine in 16 color
mode or higher, but everything comes out black on a 2 or 4 color machine.  This
is expected since standard QuickDraw isn't picky about how colors interact.

Here's the problem:  I know how to sense if a machine has Color QuickDraw, but
how do you detect the bit depth/color mode?  I don't want to move to color
windows, because I want to keep only one set of drawing routines, thus not
keeping parallel sets for standard and color quickdraw.

Here's the disclaimer:  I read through IM-V last night and the only place it
seemed I could determine bit-depth was in a pixmap record.  I checked the
portbits field of my standard window (on a 256 color IIsi) and it was a true
bitmap and not a pixmap, so I guess I can't figure things out that way.  Tech
note #276 (I think, which I don't have...) mentions a SetDepth routine.  Is
there an analogous GetDepth routine?  If so, I couldn't find it in the tech
note index.

Please help me out on this one.  At least I'm not asking about the sound
manager (yet... :-)  Thanks.

-- 
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Randall Cook
rcook@eagle.wesleyan.edu
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