Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!apple!darin
From: darin@Apple.COM (Darin Adler)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Help with LSC 3.0 CopyBits
Message-ID: <1659@internal.Apple.COM>
Date: 4 May 89 11:35:15 GMT
References: <7731@zodiac.UUCP> <741@rocksanne.UUCP> <2852@viscous.sco.COM>
Organization: Apple
Lines: 22

In article <2852@viscous.sco.COM> jamesm@sco.COM (James M. Moore) writes:
> In article <741@rocksanne.UUCP> rainero@prism.UUCP (Emil Rainero) writes:
> >I also recall reading that CopyBits wants at most 32K of data. (might want
> >to read the IM V.1 section on CopyBits.
> 
> Actually, it says that the Quickdraw convention is to not use more
> than 3k of stack space.  I presume that's to avoid possible stack
> overflows.  My question:  how does one find out what the bottom of the
> stack should be?  Seems like you could just check A7 against that
> number, and if there's room go ahead and copy more than 3k.  I've been
> copying the entire screen in one pass, and haven't noticed any
> problems (about 18k per copybits call).

This warning is fairly obsolete. The stuff regarding CopyBits and 3K in Inside
Macintosh refers to CopyBits calls that are being accumulated into a picture.
Since then, bitmap/pixmap accumulation into pictures has been enhanced, so
the 3K limit no longer applies.
to 
-- 
Darin Adler, System Software Scapegoat, Apple Computer
	Internet: darin@Apple.com
	UUCP: {nsc,sun}!apple!darin