Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!umich!samsung!dali!ogicse!decwrl!decwrl!decwrl.dec.com!joel
From: joel@decwrl.dec.com (Joel McCormack)
Newsgroups: comp.windows.x
Subject: Re: Long query about color XOR'ing
Message-ID: <3340@bacchus.dec.com>
Date: 12 Apr 90 17:25:44 GMT
References: <192@cvbnetPrime.COM>
Sender: news@decwrl.dec.com
Reply-To: joel@decwrl.dec.com
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Organization: DEC Western Research Laboratory
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>And everything looks correct, in both color and mono.  And I've just converted
>the program into a real pig because CopyPlane has gotta be one of the most
>expensive Xlib calls.

I won't go into problems with XORing in color.  It's ugly.  However, on
most modern X servers, your statement about CopyPlane is incorrect.  If
the server is careful, most hardware can paint faster using CopyPlane
rather than CopyArea.  For example, here's how many times per second you
can perform a 500x500 CopyArea from 8-bit pixmap to 8-bit screen vs.
500x500 CopyPlane from 1-bit pixmap to 8-bit screen on various machines.
 (These are numbers I know have been achieved in one server or another;
for any machine it may be that no single server achieves both numbers. 
I also know that the Sun cfb CopyPlane numbers are probably better with
the current post-R4 server Keith Packard has.)

Machine				CopyArea	CopyPlane
----------------------------------------------------------
DECStation 3100			20.0		38.0
DECStation 5000/200CX		38.8		59.1
Sun cfb				20.1		23.3
Sun GX				18.2		93.1
Newly announced machine with	 1.4		10.0
really great graphics performance purchased from another company, both
of which will remain anonymous.

- Joel McCormack (decwrl!joel, joel@decwrl.dec.com)