Re: [AD] small docs addition

["Eric Botcazou" <ebotcazou@xxxxxxxxxx>]

> Simply using 'aspect*width' is what the docs seem to imply, but it breaks
> excamera.

Yes, but I don't think we shouldn't correct a flaw just because of backward
compatibility.

> My patch leaves excamera intact, and also does no scaling in the
> sense that it does no additional scaling after correcting the viewport
> distortion.

I agree, but then it makes get_camera_matrix() depend upon
set_projection_viewport(), which IMHO is not ideal. I think the two
functions should be orthogonal... but I'm not sure.

> It also is what seems the most useful for me, because this way
> you can always use 1.0 unless you want a distorted view (or use a video
> mode with non-square pixels). It might be a good idea to clarify the docs
> a bit more about that parameter in any case.

Reading the docs, I understand that 'aspect' is simply here to tell the
camera matrix the ratio of the output image. Hence for a 320x240 viewport,
you pass aspect = 4/3. But we can of course change them.

> (I'm not a 3d expert though (that's why I'm use Allegro's 3D probably :)..

Neither me. Any 3D specialist out there ?

> so maybe the standard way is just using aspect*width, and always
> specifying the viewport correction.)

Seems more sensible (and simpler) to me.

--
Eric Botcazou
ebotcazou@xxxxxxxxxx