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From: sgi!msg@fiji.sgi.COM (Mark Grossman)
Newsgroups: comp.sys.sgi
Subject: Re: BITBLT for 3030?
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Date: 14 Jul 89 08:52:54 GMT
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Date: 13 Jul 89 17:13:57 GMT
From: Mark Grossman <sgi!msg%fiji.sgi.com@ucbvax.berkeley.edu>
Subject: Re: BITBLT for 3030?
Sender: info-iris-request@BRL.MIL
To: info-iris@BRL.MIL
References: <8907071121.aa24621@VMB.BRL.MIL>
Organization: Silicon Graphics, Inc., Mountain View, CA
Message-Id: <37889@sgi.SGI.COM>
 
In article <8907071121.aa24621@VMB.BRL.MIL>, moss@BRL.MIL ("Gary S. Moss", VLD/V
   MB) writes:
 
> however:  If the destination rectangle of the rectcopy() had an X coordinate
> which was a multiple of 16 (i.e., rectopy's 5th argument), than the copy
> was *very* fast, but anything else was blindingly slow.  I don't recall if
> the source rectangle's position was a factor or not (either it wasn't or
> my source rectangle happened to be aligned).  What I used to do was allow
 
Actually, this speedup can be achieved by ensuring that the DIFFERENCE
between the source and destination rectangle positions is a multiple
of 16.