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From: holloway@drivax.UUCP (Bruce Holloway)
Newsgroups: net.micro.atari16
Subject: Re: Alcyon C: What bugs are there?
Message-ID: <330@drivax.UUCP>
Date: Tue, 11-Mar-86 13:08:29 EST
Article-I.D.: drivax.330
Posted: Tue Mar 11 13:08:29 1986
Date-Received: Fri, 14-Mar-86 04:10:28 EST
References: <12189506892.49.UC.BRI@DEEP-THOUGHT.MIT.EDU>
Reply-To: holloway@drivax.UUCP (Bruce Holloway)
Organization: Digital Research, Monterey, CA
Lines: 43

In article <12189506892.49.UC.BRI@DEEP-THOUGHT.MIT.EDU> UC.BRI%DEEP-THOUGHT@EDDIE.MIT.EDU (Brian Totty) writes:
>	Could anyone tell me what bugs there are in the DRI C compiler?
>I am working on some GEM programs, and I keep getting bus errors (the
>ole' double mushrooms...).  I couldn't think of anything I did wrong,
>so I atarted wondering about a bug in the compiler (Yeah...if the program
>doesn't work blame it on the compiler...I know.).  In any case, the bus
>error comes in on a link instruction, which looks awfully close to a local
>variable init code.  Is there any chance that the DRI C compiler has a
>frame problem somewhere?  I would appreciate any info and possible fixes.

There ARE bugs in the Alcyon compiler (the one in the Atari developer's kit),
but they mostly have to do with automatic type conversion to/from LONGs.
Occasionally it actually ignores a line for no apparent reason (I hate it
when that happens). It's very rare, though. Either you ran out of stack
space, or it's an error in your program. I've never gotten a bus error using
the Alcyon C compiler and traced it to the compiler.

>	Also, how have people approached window text scrolling?  V_gtext
>is far too slow for a complete offset text redraw.  I would like to do
>a bit scroll, but the GEM manual was very hazy on how to do this, and I
>am not sure if desk accessories on top of a window would screw up the
>bits when scrolled.  I actually would like a scroll rectangle call like
>on the Macintosh, that gives redraw messages for the scrolled area under
>the desk accessory.  Any help here would also be great...

If you're running a desk accessory or filling out a form or a dialog box or
something similar, then no background processes are running. If you have
an active window (hence, on top), you can use the "Copy Raster, Opaque"
call (vro_cpyfm) to just BitBLT the window up one character height (said
height can be gotten from Inquire Current Face Information [vqt_fontinfo])
and another BitBLT to clear out the last row.

-- 

+----------------------------------------------------------------------------+
|Whatever I write are not the opinions or policies of Digital Research, Inc.,|
|and probably won't be in the foreseeable future.                            |
+----------------------------------------------------------------------------+

Bruce Holloway

....!ucbvax!hplabs!amdahl!drivax!holloway
(I'm not THAT Bruce Holloway, I'm the other one.)