On Thu, 21 Oct 1999, Martin Lexa wrote:
> Hi All!
[snip]
> And I've one little question about interface of kgicon 3d.
> To get 3d work I had to create new suggested strings (ACCEL_DRAWTRIANGL_3D
> and ACCEL_DRAWLINE_3D for now) and new structs
I had to do this as well for the Savage4 KGI driver.
> and I'd like to ask if
> this will be forever or is there be another concept (may be new KGI)?
Yes, the new KGI 0.9 design is the answer. It provides
'metalanguages', which should forever remove the namespace problems that
the current KGI design contains. But we do need some generic kgicommands
for 3D in the meantime. There was a thread about this topic a few weeks
back....
> If no. I've some idea what about have ioctl, for example, draw_triangle,
> which will only load parameters from struct, e.g.
>
> struct triangle {
> kgiu32 base_u, base_v, ....;
> kgiu16 r,g,b,a;
> kgiu32 x_start, y_start, z_start;
> .
> .
> .
> };
>
> With this you'll have to have some lib (like mesa target) which will do
> the programing so you won't have to have some special IOCTLs like
> DRAWTRIANGLE_TEXTURED or DRAWTRIANGLE_SMOOTH. And of course the size
> of accelerated driver will be limited to minimum. Do you understand me?
This will dramatically increase the overhead of the accel data
transfer, as you will need to send that huge struct every time, regardless
of whether all the fields are needed by the driver or any given triangle
drawing operation. Also the translation from 32bits to 16 or 8 bits would
be required in the driver itself, which would cause even more slowdown.
HOWEVER, this would definitely achieve the goal of creating a
simple, cross-driver 3D KGI development environment. And since the
existing KGI API is going to be obsoleted in the near future anyway,
perhaps it is more important right now to enable people to write 3D KGI
drivers quickly and easily and to simplify the initial GGIMesa target code
than it is to get maximum performance. Opinions, anyone?
Jon
---
'Cloning and the reprogramming of DNA is the first serious step in
becoming one with God.'
- Scientist G. Richard Seed
