Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!decwrl!claris!rick
From: rick@claris.com (Rick Boarman)
Newsgroups: comp.sys.mac.apps
Subject: Re: MacDraw II's background activity
Message-ID: <251@claris.com>
Date: 30 Mar 91 21:38:35 GMT
References: <1CE00001.bfaigj7@tbomb.ice.com> <8336@skye.cs.ed.ac.uk>
Organization: Claris Corporation, Santa Clara CA
Lines: 32


There's a couple possibilities:

1) Low memory.  We don't do any special garbage collection or weird
heap management.  The ToolBox slows down pretty bad when free memory is
less than about 100k.

2) Large files.  If there more than about ten thousand objects things can
get a bit slow (unless you have an fx).

3) Inits.  This is our biggest source of problems. Many inits eat up a lot
of time and memory.  Of all the calls to tech support a huge number turn
out to be either a strange or multiple system folders related problems.

The program itself does very little during idle time. It just tracks the
cursor and does some upkeep tasks. What are we doing about this? Well,
in MacDraw Pro we have switched over to new system calls that better
support MultiFinder (MacDraw II is a fairly old program as far as code
goes). We've done a lot to optimize performance and help manage memory 
better.  For instance, MacDraw II keeps an offscreen buffer the same
size and bit depth as the monitor.  We now crop the buffer as the window
size shrinks and we don't let it grow too big.

Hope this helps.

Rick

-- 
* Rick Boarman   *   UUCP:      {ames,apple,portal,sun,voder}!claris!rick
* Claris Corp.   *   Internet:  rick@claris.com
*                *   AppleLink: Boarman         
Opinions are mine alone and do not reflect Claris policy.