Virtual Magnifying Glass

[Sven Jaborek]

Hi

Am Freitag, den 16.06.2006, 18:56 -0300 schrieb Felipe Monteiro de
Carvalho:
> Hello,
> 
...
> > For example, i think the compiz solution will rock on desktop computers
> > with a supported 3D card. But perhaps your system rocks on laptops where
> > 3D is expensive and power extensive.
> 
> I talked to Jim Gettys about the magnifier and he proposed to utilize
> X Composite Extension to provide a better support and performance (but
> then only on computers that support it). Is that more or less what you
> are planning?

as far as i understood it, compiz utilizes a glx interface to get access
to the gpu itself.

xmcm is a program that uses composite, its allready there.

> 
> > We can work together on other things like the user interface or
> > communication interfaces, so cursor tracking is possible.
> 
> What is cursor tracking?

Magnification is only usefull if you can scale and write in parallel, so
if people write a text the expect the magnification window to move with
the cursor.

Next days and week my job is to dive into at-spi to learn how this works
in gnome.
My target for learning this is to write a piece of software that prints
the cursor/focus position on the stdout.

> 
> I do have a on-going scientific research about the usability of the
> magnifier. The answers show that the users are very satisfied. Most
> feature requests are about the dynamic mode (to be implemented with X
> Composite Extension on the near future).
> 
> http://magnifier.sourceforge.net/research.php
> 
> > Question to your magnifier, how good is the performance?
> 
> Since 3.2.1 it´s very good I would say.
> 
> > Can you magnify to fullscreen smoothly?
> 
> It works as a fullscreen software that enlarges a portion of the
> screen that is inside a glass.

i focus on fullscreen glass for now.

> 
> But an image is probably worth much more then many words, so here is a
> screenshot of it:
> 
> https://sourceforge.net/project/screenshots.php?group_id=60638
> 
> > What language is your program written in?
> 
> Object pascal, like Delphi. Althought the official compiler is Free
> Pascal you do can use Delphi to compile it. Interfacing between pascal
> and c or c++ is very easy and natural. You can even mix c / c++ object
> files with pascal ones to link and executable.
> 
> The widgetset interface links to gtk 2 on unixes.
> 
> > Does it have interfaces? Would it be possible to integrate the "enginge" into other software lice orca?
> 
> Well, not yet =) We didn´t think about that before, but this can
> probably be easely implemented, either throught a library or an
> mechanism to control the executable.

I was thinking about communication with such a "magnification-core",
too. I think other software should be able to control the glass position
and size. And for my case, full screen glass, size means scale.
For your case it size and scale have to be separated.

Iam not sure what interface is best to do this. Compiz will implement
dbus in the future, i looked at dbus and it seems to be okay. But i have
to learn dbus, too.

Any thoughts on that?

If we can define a magnifier-interface that works for many magnifier
solutions, then others can write modules or plugins or user interfaces.

Then the core is nearly independent of gnome or kde. Gnopernicus, orca
and others can use different cores for example if the interface is
harmonic. (freedesktop efforts here?)

And, image there would be multiple access to the interface. There could
be firefox plugins, or there can be other software like eye-tracking
systems or what ever. Accesibility needs are very different.

> 
> What exactly do you need? I am not familiar with orca, thought I will test it.

Thats the hardest task, defining what the interface will need.

Any ideas and hints on this are welcome.

regards, Sven

> 
> thanks,