Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!tut.cis.ohio-state.edu!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Finding the size of the screen under Multifinder/Color QD
Message-ID: <9530@hoptoad.uucp>
Date: 7 Jan 90 11:31:10 GMT
References: <10139@saturn.ucsc.edu> <9429@hoptoad.uucp> <1102@urbana.mcd.mot.com> <10164@saturn.ucsc.edu> <9490@hoptoad.uucp> <1990Jan5.234652.4485@santra.uucp>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 30

In article <1990Jan5.234652.4485@santra.uucp> jmunkki@kampi.hut.fi
(Juri Munkki) writes:
>Why would anyone want to access QD globals from a DA/XCMD? The only
>global that might be relatively useful is randSeed. To find out the
>size of the main screen, call OpenPort to open a dummy grafport. No
>need to go peeking at application/QD globals. (Unless you really want
>to.)

Nope.  The OpenPort strategy doesn't work on color systems, at least
not in the simple way you seem to be suggesting.  If you just look at
port.portBits.bounds, you'll be looking at something weird (a handle
followed by two integers) on color systems.

You can do it (code is below), but using screenBits.bounds is easier.
It also consumes much less stack space, less heap space, and less
processing overhead in OpenPort and ClosePort.

	if ((port->portBits.rowBytes & 0x8000) == 0)
		screen = port->portBits.bounds;
	else {	PixMapHandle pm = ((CGrafPtr) port)->portPixMap;
		screen = (*pm)->bounds;
	}
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com

"Now hear a plain fact: Swedenborg has not written one new truth: Now hear
  another: he has written all the old falshoods.
 And now hear the reason.  He conversed with Angels who are all religious, &
  conversed not with Devils who all hate religion..."
    - Blake, "The Marriage of Heaven and Hell"