Re: [AD] small docs addition

["Elias Pschernig" <eliaspschernig@xxxxxxxxxx>]

> > I was just using the 3d functions of Allegro for a small test
> > program, and thought it would be useful to mention somewhere
> > in the docs that Allegro uses a right-handed coordinate system.
> 
> Doesn't everyone? ;-)

Both DirectX and PovRay use left-handed, and that's all the 3D I
ever used - which is why I got confused in the program I mentioned.
I forgot what OpenGL is using, but I almost think it's right-handed..

> > There also is a small documentation mistake for get_camera_matrix().
> 
> To be fair, I never used it much, so if you say the scale factor for no 
> scaling  should be 3/4 instead of 1 I can't argue against it, but it does 
> seem strange to me.

Yes, actually, 1.0 as well as 0.75 is wrong, because it depends on the
viewport ratio. So, the correct wording should be:

(set it to (0.75 * aspect ratio of the viewport) for no scaling)

The standard viewport ratio is 4 : 3, so there the value 1.0 is right, and
that's probably how 1.0 found it's way into the docs :)

--
Elias Pschernig