Re: [AD] Patch for the documentation of polygon_z_normal()

[Andrei Ellman <ae-a-alleg@xxxxxxxxxx>]

Elias Pschernig wrote:

> I think it's a good place. Else you could move it to the beginning of
> the chapter..
> [...]
> Maybe also add a short example code how to get the normal of a triangle.
> I mean, if someone doesn't know the above information already, then that
> person certainly also doesn't know how to get the normal in the first
> place.

I think that if I give an example for how to use the alternative method 
which does not use polygon_z_normal(), then it crosses the line for 
being part of the docs for polygon_z_normal(). Do you think that a 
discussion on back-face culling should go in the bit at the begining of 
the "3D math routines" section, or in the FAQ? Bear in mind that we 
probably don't want to turn the Allegro docs into a 3D-graphics tutorial.

Also, do you think that one of the 3D examples needs to use the 
"camera->poly dot normal" method instead of polygon_z_normal()? If so, 
I'd suggest the one with the most vertices. Also, do you think Allegro 
needs an example of a light-sourced gouraud-shaded object that can be 
rotated? If so, I could supply an example. I wrote such a program for 
AllegroPak (my Allegro add-on), and if I strip away the Z-buffering and 
multiple-objects, I can easily convert it to Allegro.

AE.