R: R: [Plib-devel] Possible problem in Frustum calculation (new release?)

[Paolo L. <p.l...@ci...>]

> -----Messaggio originale-----
> Da: pli...@li...=20
> [mailto:pli...@li...] Per conto di steve
> Inviato: sabato 26 novembre 2005 16.01
> A: pli...@li...
> Oggetto: Re: R: [Plib-devel] Possible problem in Frustum=20
> calculation (new release?)
>=20
>=20
> Bram Stolk wrote:
> > Paolo Leoncini wrote:
> >=20
> >> Please consider inserting the following patch to sg.cxx for working
> >> around
> >> the subject problem:
> >=20
> >=20
> > Paolo,
> >=20
> > I would like to help you, but check out this thread:
> >=20
> >=20
> =
http://sourceforge.net/mailarchive/forum.php?thread_id=3D6692659&forum_i
> > d=3D4479
> >=20
> >=20
> > field-of-view behaviour is tricky.
> > Sometimes, you want the behaviour you implemented:
> > fix one fov dimension, and set the other depending on the window=20
> > aspect ratio. Sometimes, you want a fixed aspect, like=20
> steve described=20
> > in the thread. And in other cases you may want the current plib=20
> > behaviour. (Altough I agree that this messes up ratio's, and looks=20
> > ugly).
>=20
> Exactly.
>=20
> Whichever you do will displease roughly 50% of developers. =20
> We picked one at the outset - if we change it, we'll at best=20
> upset 50% of developers - and do nothing for the other 50%=20
> who have already worked around the issue.

The idea is to fix things for casual users who don't want to complicate
their life with frustum extents whilst getting their setFOV honored (and
don't want to ugly multiply the hfov by 1.045 at 60=B0).

IMHO whoever has worked around the problem did it with explicit frustum
extent calculation as Bram's code shows, which has a different path =
within
sgFrustum::update yet.

> At worst, we'll upset 100% of developers because the library changed
> in ways they didn't expect.

... or many could finally see actual spheres!

Seriously, I don't fully understand the referred post about the freedom =
left
by the current behavior, I'm just a little disappointed having had a =
wrong
aspect ration for five years, and for the last two years having worked
around with an unexplainable constant multiplication, and would like =
other
users don't do the same.

> We shouldn't do this.

Ok, at leat what about warning setFOV users anywhere in the doc that =
putting
e.g. (60, 45) args for a 4:3 window doesn't produce an isotropic coord
space?

Paolo