From: Andrew Apted <ajapted@netspace.net.au>
  To  : ggi-develop@eskimo.com
  Date: Wed, 19 Aug 1998 14:00:47 +1000

Re: LibGGI3D RFC

Jon writes:

>  III. Design specifics.
>  
>  * struct camera { float x1, y1, z1, x2, y2, z2 }. Every LibGGI3D display
>  will have a camera struct attached to it.  A generic hook for arbitrary
>  display data should also be present - the shaders might use it.  void
>  *private_data. 

I guess x1,y1,z1 is the camera position, and x2,y2,z2 is the normal to
the viewplane, but what about the orientation of the viewplane (the "up"
vector for want of the precise term) ?

>  * int DrawTriangle (float x1, y1, x2, y2, x3, y3; shader_index shader; void
>  *shader_data) is the core drawing function.

Are those coordinates on the screen ?  Or should they be world space and
have z1,z2,z3 as well, where DrawTriangle() does the translation of
world space to screen space ?

Cheers,
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  Andrew Apted   <andrew@ggi-project.org>       \/