From: teunis <teunis@computersupportcentre.com>
  To  : ggi-develop@eskimo.com
  Date: Thu, 20 Aug 1998 13:44:33 -0700 (MST)

Re: LibGGI3D RFC

On Thu, 20 Aug 1998, Jon M. Taylor wrote:

> On Wed, 19 Aug 1998, teunis wrote:
> 
> > On Wed, 19 Aug 1998, Jon M. Taylor wrote:
> > 
> > > On Wed, 19 Aug 1998, teunis wrote:
> > 
> > [clip]
> > 
> > > > Now thinking about it:
> > > > 	Coordinate clipping requires info about -all- present coordinates.
> > > > 		(X,Y,Z[,W][,U,V[,U2,V2..]][colour])
> > > > 	mayhaps we need to think about this further?  (don't know)
> > > 
> > > 	The higher layers could clip during tesellation, and as such
> > > they'd be able to take all those coordinates into account.
> > 
> > Ah - so the only clipping libGGI3D would do would be?
> 
> 	Render-side clipping. if anything. 
> 
> > I'm curious, as moving any of the X,Y[,Z] coordinates will affect the
> > remainder of the coordinate list...
> 
> 	For one triangle this shouldn't be a problem.  For a set, you do
> what you can. 

so what happens if you clip a triangle and you lose the corner [u,v]
coordinates?  All of a sudden your texture is moving around when it gets
clipped.  The same happens for colourblending when you have discrete
colour components per-corner - all of a sudden your blends get messed
up...

How do you mean to handle this?

> > > > >  - I want clipping in libggi3d also.
> > > > 
> > > > See above...  and this requires also the camera info (view frustrum,etc)
> > > > to be available....
> > > 
> > > 	Right. 
> > 
> > So how does this work?
> 
> 	Attach it as a struct to the visual. 

not what i meant *sigh*.  I mean how do you expect clipping to work?

[clip]
> > Though there should be some kind of internal mechanism for handling
> > display memory!  (so it doesn't get all fragmented and can be used
> > effectively!)
> 
> 	I guess the buffer system doesn't *have* to be in a target.  AAIK 
> is isn't(?) in LibGGI2D.

Supposedly DirectBuffer handles this.  Will someone -please- tell me the
status on non-primary-display DirectBuffers?!?!?!?!??!
WHAT NEEDS DOING?

G'day, eh? :)
	- Teunis