[chimera-dev] accelerators and stereo

[Matthew Dougherty]

>===== Original Message From Thomas Goddard <goddard at cgl.ucsf.edu> =====
>Hi Matthew,
>
>  I don't understand what you mean by "the stereo quarter of the display".
>Is this some special monitor?
>

standard monitor & graphics hardware.
when stereo hardware is engaged (ircombine or setmon), the computer reduces 
the display by two on each axis.  It does this to create the left and right 
display 
buffers out of the single monographic display buffer, a limited graphical 
resource.

when it sends out the stereo display buffers it doubles the output pixels, 
hence the objects (e.g. desktop icons) look twice as big.  What used to take 
one pixel to display is now using four pixels.

at the same time the emitter activates the googles, polarizing (making opaque)
one eye, and transparent the other; on the screen the two display buffers,
are put on the display, alternating typically 1/30 apart.


most people use the top left area/ top quarter, where the tool chest is 
located, typical default for sgi, but can be overridden.

unfortunately, when stereo mode is engaged the screen size is not adjusted 
within the x window manager as it should be (SGI or X design bug), so you have 
anomalies like the mouse being able to go off the visible display, or allowing 
windows to startup off the visible display; because the x window manager is 
working with 1024x1200 (mono) when in reality the display area is 512x600 
(stereo).  This may be solvable by application code.


>  Chimera uses stereo in a window provided by the OpenGL graphics library.
>
which gets it from the x window manager

>  Chimera does not provide a way to specify the starting positions of
>its windows.  Initial placement of windows is usually managed by your
>windowing system, not by individual applications.
>
>	  Tom

------------------------------------------
     Matthew Dougherty/713-433-3849
National Center for Macromolecular Imaging
       Baylor College of Medicine