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From: janssen@parc.xerox.com (Bill Janssen)
Newsgroups: comp.soft-sys.andrew
Subject: speed of drawing text under OW 2.0
Message-ID: <4atO1xMB0KGW45dd89@holmes.parc.xerox.com>
Date: 6 Sep 90 01:03:57 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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We've noticed that Andrew typescript (and ez, etc.) scrolls much more
slowly under OpenWindows 2.0 than does X11R4 xterm (perhaps 6-8 times
more slowly), on a Sun (SunOS 4.0.3) SparcStation-1 with a GX board. 
This seems to be because Andrew uses "PolyText8" X protocol requests to
draw strings, and xterm uses "ImageText8" to draw strings.  "PolyText8"
is a much more general request than "ImageText8", and apparently
underoptimized in the OW server.  As far as I can see in traces of the
typescript tool, Andrew doesn't use the more general facilities of the
"PolyText8" request, and could use the simpler and
more-likely-to-be-optimized "ImageText8" request instead.  That is,
Andrew seems only to draw one TEXTITEM at a time, they always seem to be
strings (never offsets or fonts), and they always seem to use the same
font.

It would seem possible to change the call to XDrawString in
atk/basics/x/xgraphic.c to a call to XDrawImageString, without
disturbing anything.  We'd still revert to XDrawText (and thus
PolyText8), when drawing complicated fonts, but would win on drawing
simple fixed-width fonts.

Any quarrels with this analysis?

Bill