Hi,
As far as I remember from the last time I looked at the SI/Windows
code, this was not too hard since there were appropriate function
pointer tables for say cards that didn't do T&L, setup, or whatever.
Perhaps John just meant to say that doing this isn't necessarily a
fill in the blanks exercise?
Certainly a whole bundle of cards without T&L have used this codebase
to base their drivers on.
nate
> Sure, for the future and to support hardware T&L, the OpenGL API
> really is the device driver layer for the most part. However although
> all interesting new hardware has hardware T&L, there are still
> literally millions of good boards out there in the field that don't
> have this! Hence we need to way to ensure that we can provide good
> solutions for legacy hardware (hell, are we *already* at the stage of
> calling the TNT2 and Voodoo3 legacy hardware!).
>
> So my idea is that we need a layered device driver model. One layer
> is for cards with only 2D acceleration, and most does all the
> rendering in software (with perhaps an accelerated screen clear and
> 2D primitives ;-). The next layer is for rasterisation only hardware
> and provides a device driver model for that. The next layer above
> that is for harware T&L, where a large portion of the OpenGL API
> functions go directly into the device driver layers (once you do all
> the usual OS specific stuff for managing threads etc).
>
> An abstract API for all this stuff is certainly possible. If it
> wasn't, Direct3D immediate mode would not exist ;-)
>
> Regards,
>
> +---------------------------------------------------------------+
> | SciTech Software - Building Truly Plug'n'Play Software! |
> +---------------------------------------------------------------+
> | Kendall Bennett | Email: KendallB@xxxxxxxxxxxxxxx |
> | Director of Engineering | Phone: (530) 894 8400 |
> | SciTech Software, Inc. | Fax : (530) 894 9069 |
> | 505 Wall Street | ftp : ftp.scitechsoft.com |
> | Chico, CA 95928, USA | www : http://www.scitechsoft.com |
> +---------------------------------------------------------------+
>
|