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From: bin@primate.wisc.edu (Brain in Neutral)
Newsgroups: comp.sys.mac.programmer
Subject: Re: How to get sizeRect?
Message-ID: <3777@uakari.primate.wisc.edu>
Date: 18 Jan 91 17:54:37 GMT
References: <1991Jan18.153558.4723@nada.kth.se>
Sender: bin@primate.wisc.edu
Reply-To: bin@primate.wisc.edu
Lines: 27

From article <1991Jan18.153558.4723@nada.kth.se>, by d88-jwa@dront.nada.kth.se (Jon W{tte):
| In article <3770@uakari.primate.wisc.edu> bin@primate.wisc.edu writes:
| 
|>This is somewhere in Inside Macintosh V (Graphics Device chapter, I believe).
|>Possibly you need to check whether the trap exists and use the low memory
|>global GrayRgn instead if it doesn't.  Of course, depending on how
|>GetGrayRgn() is implemented, it might simply return the value of GrayRgn
|>itself!  Anyone know?
 
| GetGrayRgn ( ) is [ Not In ROM ] - if the call's not there, the
| global ain't either. Check for old ROMs or something instead...
| New Sys software should provide the GetGrayRgn ( ) call on any
| machine.

Well, um.  I have written a "tell me about this system" application that
looks at both the GetGrayRgn() result and at GrayRgn.  The systems I've
run this on so far show identical results.  Just like for GetMBarHeight()
and MBarHeight (although this latter test would certainly fail on 64K ROM
machines, since they have no MBarHeight global according to TN 117 p7).

Just because the glue code executed for GetGrayRgn() isn't
in ROM doesn't mean it doesn't access any globals.  It might not,
but I doubt that the absence of the global can't be inferred from
the presence of the function.

Paul DuBois
dubois@primate.wisc.edu