[scilab-Users] Re: [Scilab-Dev] Scilab 5.2 Beta available

[StŽéphane Mottelet]

Pierre LANDO a écrit :
> Stéphane Mottelet a écrit :
>> Hi all,
>>
>> just a question/remark. Since version 5, we have a powerfull rendering
>> engine for graphics, but I still do not understand one particular point
>> about interpolated shading. I know that Scilab still works with an
>> indexed color scheme, but why interpolated shading still works by
>> cuting triangles into constant color patches ?
>
> Maybe for being compatible with scilab 4, but I'm not sure at all...
>
>> This generates artifacts when exporting figure to ps,pdf,svg,...
> You don't have the same result because it's not JoGL who make the 
> exported files (in vectorial format).
> You better should be happy to have something viewable when you export 
> in vectorial format :o)
Well, I thought that most "modern" vectorial formats (pdf, svg,...)
implemented  natively interpolated color patches, but after a quick 
search on
the net, I realized that these format only take into account gradients. 
At least
with svg, this could be a way to emulate interpolated shading for triangles.

> (see http://bugzilla.scilab.org/show_bug.cgi?id=4866).
>
>> I think that JoGL should be able to use hardware bilinear shading,
>> even with indexed colors (instead of TrueColor).
> You are right, (modulo drivers problems), actually  the 'indexed 
> color' is see by JoGL as a 1D-texture, nothing simplest as activating 
> bilinear shading for the OpenGL texture.
>
> But, it's look like that some people don't want to see in a graphic a 
> color who doesn't exist in the colormap (very old trauma related to 
> VGA display and is 0x13 mode).
Ok, but, Matlab has no problem to render interpolated colors with an 
indexed color visual. This should be doable in Scilab ?

S.