Re: [g-a-devel]Re: [blindpng sdf lonestar org: Full Screen Magnification for X Windows] (fwd)

[Bill Haneman <bill haneman sun com>]

On Wed, 2003-03-12 at 17:42, Kieran O'Sullivan wrote:

HI Kieran:

It would be very nice if you could build on our existing work, it's nice
to avoid duplication of effort, multiple incompatible implementations,
etc.  Can you tell us why you want to do your own project instead?

I have lots more comments below...

> At the moment I still want to persew my own little project but I will
> contribute anything I find out or build to the gnome.  I do have some
> questions and observations.
> NOTE I'm not yet on the gnome-accessibility-mailing list so please send
> mails to me directly.
> 
> 1. It is definately curcial to have X server support for full screen
> magnification if gmag is aver going to do full screen magnification how is
> it going to get around this I can't see any way other than using
> Xlib/DGA/SVGALib/Something else I'm not awaire of yet.

Maybe I should rephrase what I said earlier: we have X server support
for fullscreen magnification in the "X virtual screen" project and also
it can be done without the 'virtual screen' if you have a Matrox video
card or otherwise have two frame buffers.  Of course you only need a
monitor attached to the magnified screen, not the unmagnified (possibly
virtual) one!


Our project, gnome-mag, which runs on GNOME 2.0 is a lot different from
gmag, and I think you will find that it is much more like what you need.

gnome-mag includes a standalone magnifier, "magnifier", which can be
used in half-screen or fullscreen mode (fullscreen mode requires two X
DISPLAYs, but only one needs to be physically "real").

Also the gnopernicus screenreader/magnifier offers full-featured
magnification support via the gnome-mag services, including different
kinds of mouse-push modes, focus tracking, etc.  much like commercial
magnifiers for Windows.

We could really use your feedback on these "live" projects and even
contributions, so I encourage you to try them out rather than just
pointing out the limitations of older GNOME magnification software :-) 
We agree with you about the limitations of magnification in a small
window, and other issues with gmag, xmag, and similar X/gnome
magnifiers, this is why we wrote gnome-mag.

best regards,

Bill

> This is mainly an observation but I downloaded gmag from a blind linux
> site recently and ran it (I can't recall what version it was).  While it
> magnified the screen the only way I
> can describe it is as "asperational access" in othe words it isn't really
> useable.  I say this because I wrote a similar program for a college
> project 2 years ago and that led me to the conclusion that magnification
> in a small window is un-workeable.  I still have nightmares about all the
> little hacks I tried to get the window to stay on top.


> If anyone does not believe me that magnification in a small window is not
> workeable try the following start gmag.  Take a black sheet of paper and
> cover your monitor but cut a hole to match the size of the gmag window now
> start using!
> 
> WARNING don't cover the vents at the back of your monitor or bad things
> could happen.  This is a don't put your dog in the microwave warning i.e.
> obvious to anyone with even half a brain.
> 
> I'm sorry if I have insulted anyone or trashed anyone's hard work but I
> can't make this point strongly enough FULL SCREEN MAGNIFICATION IS THE
> ONLY WY TO GO and if you want that then sooner or later you are going to
> have to get down and dirty with something a lot nastier than the TK's
> provided by Gnome Kde or anyone else.
> 
> 
> 
> On 12 Mar 2003, Michael Meeks wrote:
> 
> > Date: 12 Mar 2003 12:33:20 +0000
> > From: Michael Meeks <michael ximian com>
> > To: Kieran O'Sullivan <blindpng sdf lonestar org>
> > Cc: Osvaldo La Rosa <info brlspeak net>,
> >      accessibility mailing list <gnome-accessibility-devel gnome org>
> > Subject: Re: [blindpng sdf lonestar org: Full Screen Magnification for X
> >     Windows] (fwd)
> >
> > Hi Kieran,
> >
> > 	Osvaldo forwarded me your mail:
> >
> > 	As you notice, it is almost crucial to have Xserver support to do fast
> > magnification - particularly for the scaling.
> >
> > 	However - we already have a working project using Gnome a11y
> > infrastructure - which lets us do some very nice things (well beyond
> > following the mouse), which is fairly powerful already.
> >
> > 	It's called 'gnome-mag', it's in Gnome CVS (see
> > http://developer.gnome.org/). Of course - it requires a fairly recent
> > Gnome [ 2.2 should do nicely ], and works best in conjunction with
> > gnopernicus, also from CVS there.
> >
> > 	It'd be great to have you working with us, improving this.
> >
> > 	Best regards,
> >
> > 		Michael.
> >
> > On Tue, 2003-03-11 at 16:28, Osvaldo La Rosa wrote:
> > > ----- Forwarded message from Kieran O'Sullivan <blindpng sdf lonestar org> -----
> > > Date: Mon, 10 Mar 2003 11:45:06 +0000 (UTC)
> > > From: "Kieran O'Sullivan" <blindpng sdf lonestar org>
> > > Subject: Full Screen Magnification for X Windows
> > > To: debian-accessibility lists debian org
> > >
> > > BlindPenguin - X Windows Accessability Project
> > > http://www.blindpenguin.org
> > > kieran osullivan blindpenguin org
> > > SDF Public Access UNIX System - http://sdf.lonestar.org
> > >
> > > I am writing an Xlib (written in c) based screen magnification program for
> > > X Windows called BlindPenguin (http://www.blindpenguin.org).  I am posting
> > > to this group to get ideas on a technical issue with the program.  The
> > > issue is this any X magnification program that I have seen draws the
> > > magnified area on a window I DO NOT WANT TO DO THIS.  I want to write a
> > > program, which zooms in like a video camera on a particular part of the
> > > screen what will happen is that the magnified area of the screen will
> > > fill the entire screen, in simple terms the magnified area will be re-drawn
> > > with more pixels to fill the screen.  However the X server and clients
> > > shouldn't care about this in-fact they shouldn't know.  Basically there
> > > are 2 screens 1 is the screen that the X server creates and the other is
> > > the screen that the user sees.  As I move the mouse around the X server
> > > moves it on the real screen but the user sees the magnified screen moving.
> > >   To use the video camera analogy again imagine a person walking around a
> > > room using the view finder of a video camera turned up to full zoom to see.
> > >  Their coordinates would change relative to the objects in the room but they
> > > would see things much larger than they are.
> > >
> > > WHAT I AM LOOKING FOR
> > >
> > > I am looking for ideas or code that will help me do this Especially DGA
> > > code.  Also anyone who
> > > has knowledge of how programs like ZoomText or Lunar do this in Windows
> > > I would like to hear of it, I know that ZoomText doesn't work in X but
> > > the ideas may inspire me.
> > >
> > > THIS PROGRMA WILL BE RELEASED UNDER GPL
> > --
> >  mmeeks gnu org  <><, Pseudo Engineer, itinerant idiot
> >
> >
> 
> BlindPenguin - X Windows Accessability Project
> http://www.blindpenguin.org
> kieran osullivan blindpenguin org
> SDF Public Access UNIX System - http://sdf.lonestar.org
> 
> Full Screen Magnification for X Windows
> 
> I am writing an Xlib (written in c) based screen magnification program for X Windows called BlindPenguin (http://www.blindpenguin.org).  I am posting to this group to get ideas on a technical issue with the program.  The issue is this any X magnification program that I have seen draws the magnified area on a window I DO NOT WANT TO DO THIS.  I want to write a program, which zooms in like a video camera on a particular part of the screen what will happen is that the magnified area of the screen will fill the entire screen, in simple terms the magnified area will be re-drawn with more pixels to fill the screen.  However the X server and clients shouldn't care about this in-fact they shouldn't know.  Basically there are 2 screens 1 is the screen that the X server creates and the other is the screen that the user sees.  As I move the mouse around the X server moves it on the real screen but the user sees the magnified screen moving.  To use the video camera analogy again imagine a person walking around a room using the view finder of a video camera turned up to full zoom to see.  Their coordinates would change relative to the objects in the room but they would see things much larger than they
> are.
> 
> WHAT I AM LOOKING FOR
> 
> I am looking for ideas or code that will help me do this.  Also anyone who has knowledge of how programs like ZoomText or Lunar do this in Windows I would like to hear of it, I know that ZoomText doesn't work in X but the ideas may inspire me.
> 
> THIS PROGRMA WILL BE RELEASED UNDER GPL
> 
> _______________________________________________
> Gnome-accessibility-devel mailing list
> Gnome-accessibility-devel gnome org
> http://mail.gnome.org/mailman/listinfo/gnome-accessibility-devel
-- 
Bill Haneman <bill haneman sun com>