RE: [LIBART] problem with art_rgb_svp_alpha()

[Lauris Kaplinski <lauris ximian com>]

Hello!

Doy you call art_vpath_perturb?
It distorts points by microscopic distances, thus probably killing many numerical
stability problems. It helped me - and from your point list I saw, you have
colienar segments...

Lauris Kaplinski

On 06 Mar 2001 07:56:51 -0500, Jason Priebe wrote:
> > > I'm generating an svp from a set of 23 points.  I pass
> > > that into art_rgb_svp_alpha(), and it hangs.  I've used
> > > gdb to trace it to line 283 in  art_svp_render_aa.c.
> > 
> > How exactly do you generate the svp ?
> > The correct way is to build a vpath and either
> > art_svp_vpath_stroke or art_svp_from_vpath it.
> > For the latter, the surface (I assume the vpath is closed) outline
> > must be given counter-clockwise.
> 
> Sorry -- I should have been more specific.  I'm taking the
> point list that I sent in my previous message and building
> a vpath from it.  Then I call
> 
> art_svp_vpath_stroke(vpath, ART_PATH_STROKE_JOIN_ROUND,
>                                         ART_PATH_STROKE_CAP_ROUND,
>                                         STROKE_WIDTH,
>                                         0.0,
>                                         0.25);
> 
> The resulting svp is passed to art_rgb_svp_alpha().
> 
> The path is not closed, and the points are completely arbitrary;
> the data comes from handwritten strokes.  Are there preconditions
> that must be met in order to use art_svp_vpath_stroke()?
> 
> Jason Priebe
> Mi-Co
> http://www.mi-corporation.com/ 
>