Re: IR Onyx2 which rastermanager ?

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Amit Parghi (amit++at++Discreet.COM)
Tue, 17 Jun 1997 17:46:38 -0400

David Nouls wrote:
> We need to have Multisampling on an Onyx2 with IR at Full Overscan PAL
> resolution.
> How many and which rastermanagers do we need for this ? What are the
> differences between RM6, RM7 and RM8 ?

There are several questions here. Basically, the short answer is that more
information is needed to give you a useful answer. However, the other short
answer is: If you need 1280x1024 with double-buffered multisampling but
*don't* need stencil planes, accbuffer, etc., then there are several
visuals with 12-bit RGBA and four-sample multisampling that are available
with just one RM7.)

First, for an Onyx2/iR, you will only have RM7 raster managers; the RM7
comes in two models, one with 16MB of texture memory and one with 64MB of
texture memory (use /usr/gfx/gfxinfo to see which you have). Both models of
RM7 have the same amount of frame buffer storage, so this won't affect the
number of RMs needed to achieve a particular pixel depth.

The number of RMs you will need is dependent on the total frame buffer
space you'll need: this in turn is a function of your total "managed area"
(i.e., the total area of frame buffer space across all video channels) and
the "pixel depth" (the number of bits per pixel, generally labelled as
small/medium/large/xl). The pixel depth in turn depends on more than just
multisampling: there are a number of different GLX visual settings
available (for each area/depth combination) that provide different
combinations of:
        - R/G/B/A planes (most at either 10 or 12 bits depth)
        - double-buffering
        - depth (Z) buffering
        - stencil buffers
        - accumulation buffers
        - multisample buffers
        - aux buffers
For a particular managed area setting (as set up and installed with
/usr/gfx/ircombine), you can get a list of the available visuals with
'glxinfo'.

So, what you'll need to determine (in addition to multisampling and "full
overscan PAL") is the total area in the frame buffer (i.e., the console +
any other video channels) and the total depth required (i.e., all the
buffers you need).

Amit

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