www.delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1996/11/28/12:34:00

Date: Thu, 28 Nov 1996 12:21:49 -0500 (EST)
From: Glen Miner <gminer AT Newbridge DOT COM>
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
cc: djgpp AT delorie DOT com
Subject: Re: Djgpp and Windoze Refresh
In-Reply-To: <Pine.SUN.3.91.961128191530.9387A-100000@is>
Message-ID: <Pine.SUN.3.90.961128122054.3514A-100000@coop10>
MIME-Version: 1.0

> > However, there have been confirmed allegations that my program fails to
> > correctly redraw the screen when it is placed in the background and then
> > brought to the foreground again.
> 
> The following excerpt is from the DJGPP FAQ list.  I don't know whether
> this is true for Windows 95, and if so, what are your options other than
> the ``redraw screen'' thingy suggested below. 
> 
> 10.3 Graphics screen restoring under Windows
> ============================================
> 
> **Q*: When I switch away from my DJGPP program under Windows, then switch
> back to it, graphics mode is down, or my screen is all messed up.  Why?*
> 
> *A* :  Windows only saves the VGA screen in standard VGA modes (1..13h) when
> you switch away from a DOS application.  In any other mode it only
> saves/restores the video mode *number*, but not the actual screen contents.
> Your application is most likely still in the proper video mode (if not, it's
> probably the fault of the Windows driver for your SVGA card), but the video
> memory is messed up.  The beauty of all this is that your program has no way
> of knowing that the screen has been taken away and then returned to it.
> 
> The only reasonable thing to do is to dedicate a "hotkey" in your application
> (e.g., `Alt-R') whose action is to redraw the entire screen.  If you do that,
> it's best to start all the way from the beginning, with a call to
> `GrSetMode', as there are a few bad Windows video drivers which do not
> restore SVGA graphics modes properly upon the switch back.

I had already read that section of the faq; I had posted in the hopes 
that somebody had come up with a better solution. :(

Peace
===[ Gabo / [ABC] : gaminer AT undergrad DOT math DOT uwaterloo DOT ca ]===================
Latest ABC Shogi: http://www.undergrad.math.uwaterloo.ca/~gaminer/shogi.html
"What Greenpeace spends in a year General Motors spends in four hours" -Moby

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019