Re: [RFC] Gradient fill options

[Pierre <pie...@gm...>]

On 2/7/07, Pierre <pie...@gm...> wrote:
> On 2/7/07, Ethan Merritt <merritt@u.washington.edu> wrote:
> > On Wednesday 07 February 2007 11:44, Hans-Bernhard Br=F6ker wrote:
> > > Pierre wrote:
> > >
> > > > I'm not sure to understand why it is biased. Each vertex color is
> > > > known. The first vertex is the top left one, after they have been
> > > > sorted.
> > >
> > > The bias lies in picking the top left vertex as "the first".
> > > This can cause nasty effects like: the same triangle comes out subtly
> > > different if the scene is rendered upside down or rotated by 90 degre=
ss,
> > > even though the result should be exactly the same.
> >
> > That is true, but the failure mode is usually harmless. If you rotate t=
he
> > triangle in 3D its coloring may change very slightly, but if it is a
> > single facet of a larger surface this will probably not be noticed sinc=
e
> > the adjacent triangles are similarly affected.
>
> I will add a custom version to test these cases using numerical
> results (output the edges values to a file and compare them). We can
> then see if the error is acceptable. As you say, I do not expect any
> noticeable differences.

By the way, any help is welcome. If someone volunteers to write these
tests, he will be more than welcome :)

--Pierre