Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!ukma!uflorida!stat!sun13!loligo!bauer
From: bauer@loligo (Jeff Bauer)
Newsgroups: comp.windows.x
Subject: Re: xplato
Message-ID: <87@sun13.scri.fsu.edu>
Date: 13 Jun 90 18:40:48 GMT
References: <9006131001.AA04603@shamash.McRCIM.McGill.EDU>
Sender: news@sun13.scri.fsu.edu
Organization: Florida State University
Lines: 52

In article <9006131001.AA04603@shamash.McRCIM.McGill.EDU> mouse@SHAMASH.MCRCIM.MCGILL.EDU (der Mouse) writes:
>I wrote a program that wanted to display double-size characters.  What
>I eventually did was to generate bitmaps and display them with
>XCopyPlane.  I would strongly recommend you do the same.  Actual
>displaying of the characters will probably be slower than using fonts,
>but it will almost certainly cut down drastically on the overhead and
>will actually be portable, even to X terminals and the like.

I'll try XCopyPlane.  Sounds good.  Seems any local X stuff is much faster
than the PLATO engine at the other end of the telnet socket anyway.  I
wasn't too happy with the "BDF compile" kludge, but it DOES work for the
case of local X server gabbing and proved the whole idea was at least
doable.

>...I'll likely hack on it to fix the alternate
>charset issue.  (I have a question, first; does the protocol place a
>limit on the size of an alternate character?  As I recall from my PLATO
>experience (years ago), it does, and as you imply as much in the first
>paragraph I quoted.)

An alternate character is width 8 by height 16 as defined by the
protocol.  Of course, size 2 stuff is twice as large.  Those should be
the only two sizes any PLATO emulator should have to worry about.

>
>I also notice the presence of a line-drawing mode.  Does the PLATO
>protocol specify pixelization rules, and did you make sure your X code
>follows them if so?

The protocol says nothing about aliasing or any other aspects of
line drawing.   I don't do anything special.  For what it's worth, the
graphics output has the "look and feel" of PLATO on a normal PLATO
terminal (even if it is screaming for aliasing).

Also, if you nabbed a copy in the last few days and had problems with
garbled graphics output, try nabbing a new copy (or just grab the
"xplato.c" file and rebuild).  I corrected a big/little-endian bug
that caused (at least) MIPS-based DECstations to freak.

>
>					der Mouse
>
>			old: mcgill-vision!mouse
>			new: mouse@larry.mcrcim.mcgill.edu
>
>(A copy is being sent to xpert in the hope of keeping someone else
>from making the same mistakes.  They're natural mistakes for someone
>new to X, but still mistakes.)

Thanks for the comments!
Jeff Bauer				bauer@loligo.cc.fsu.edu
FSU Computing Center Systems Group	(904) 644-2591 x. 113