From: teunis <teunis@computersupportcentre.com>
  To  : ggi-develop@eskimo.com
  Date: Mon, 17 Aug 1998 12:36:18 -0700 (MST)

Re: 3d

On Mon, 17 Aug 1998, James A Simmons wrote:

> > Martin Hess wrote:
> > > 
> > > I am thinking about helping with the 3d part of GGI. Specifically I would
> > > like to support the Matrox G200.
> > > 
> > > Where do things stand today on the 3d front? I didn't find anything in the
> > > sources. Is development active? Is there a strategy in place?
> > 
> > The strategy is to not have any strategy! :o)
> 
> Actually there is a strategy. 3D was the reason for me to join GGI. 
> First we provide basic 2D support for all platforms and hardware. This is
> so we can come up with a standard API that will work with everything. As
> for 3D for right now I plan to put this stuff into kgicon/kgi/accel for
> serveral cards. Right now kgicon does use any hardware accels but as more
> advance features are added we can develope a standard API for 3D stuff.

IMHO agreed.  I've thought long and hard about this and think this is the
only way...  (but I've been wrong many, many times before:)

I've got some ideas and the beginnings of a software-driven kit but
recently I've had it drummed into me by my inventor/mathematician brother
that I've been looking at it all wrong *sigh*

> > Nothing of this is done yet. You will have to plunge into unknown water.
> 
> Why we are discussing this. I have been working with the TGA video adapter
> and have notice it supports gourand shading and z buffering. It does not
> have texture mapping. Alot of cards have gourand shading and z buffering. 
> How should we support this? Any ideas?

Gouraud shading:  the ability to push 1+ colours into a graphics command;
	Non-gouraud - just assume the last colour is valid
	Gouraud-shaded - blend as many colours as supported.
Some kinda API should be done for this though - some kind of extension to
libGGI2D I would guess (as soon as it reappears?)

Z buffering - DirectBuffer - type = "Z-buffer".
	[I have yet to see hardware where this is joined with colour -
	 all I've seen (S3) use a seperate buffer]

Texture Mapping - DirectBuffer - type = "HW subdisplay"

G'day, eh? :)
	- Teunis

PS: On the DirectBuffer comments - IMHO support isn't ready for this
either yet but this one -should- be done soon!  Especially
texture-mapping (for 2D BITBLT support if nothing else as this is how the 
blitting normally works on intel/compatible (IE has PCI) hardware.
Flat-memory systems of course are much simpler :)
(simpler = alot easier to allocate/control memory, commands are usually
identical)