Re: [AD] triangle3d_f with | POLYTYPE_ZBUF bug

[Javier González <xaviergonz@xxxxxxxxxx>]

Hmm. I thought Bertand forgot to say "Please commit it" ;)

----- Original Message -----
From: "Bertrand Coconnier" <bcoconni@xxxxxxxxxx>
To: "Allegro Conductors" <conductors@xxxxxxxxxx>
Sent: Sunday, January 07, 2001 4:40 PM
Subject: Re: [AD] triangle3d_f with | POLYTYPE_ZBUF bug


> Javier González wrote :
> >
> > Hello, I've noticed that if i use:
> >
> > triangle3d_f(buff, POLYTYPE_GCOL | POLYTYPE_ZBUF, NULL, v[0], v[1],
v[2]);
> >
> > that wont work properly, meanwhile when i switched it to:
> >
> > polygon3d_f(buff, POLYTYPE_GCOL | POLYTYPE_ZBUF, NULL, 3, v);
> >
> > (it's supposed to be the same) that works...
> > i haven't tested the fixed version, but maybe buggy too...
>
> Bug fixed ! See attached file : this is the smaller patch ever sent to
> this mailing list ;-)
> To fix the bug in your lib you may :
> 1. apply the patch
> 2. do it yourself :
> - open poly3d.c
> - goto line number 1420 (float z1 = 65536. / v->z;)
> - replace 65536. by 1. (the line should then looks like : float z1 = 1.
> / v->z;).
> - save and quit
> - recompile of course :-)
> - That's all folks !
> BTW fixed point version of triangle3d is not buggy.
>
> Bertrand.


----------------------------------------------------------------------------
----


> --- poly3d.c.old Sun Jan  7 03:39:48 2001
> +++ poly3d.c Sun Jan  7 03:40:07 2001
> @@ -1418,7 +1418,7 @@
>        float w1 = 65536. / w;
>
>        /* Z (depth) interpolation */
> -      float z1 = 65536. / v->z;
> +      float z1 = 1. / v->z;
>
>        info->dz = (s1->z - z1) * w1;
>
>