[PD-dev] [GEM] cvs

[guenter geiger]

On Fri, 9 May 2003 zmoelnig at iem.at wrote:
> unfortunately i am not sure, whether the only use of [pix_rgba] is for
> conversion into "native" colour-space.
> sometimes i really like having an alpha-channel....

I was thinking the "native" colorspace is with alpha channel, but with
yuv this is not the case, as I have heard.
(In the film example pix_rgba was used to convert from RGB to RGBA,
which I thought is a bit strange).

Yes the alpha channel is quite nice in several circumstances ..
will this be lost on OSX when there is no pix_rgba ?

Guenter


>
> > > >rgba-format for mac is GL_ABGR_EXT, so i changed it to this (but i
> > > >have not tested it)
> > >
> > > pix_rgba should have no function on OSX at all.
> (see above)
>
> > > patch, it may be useful for implicit color-conversion, but that's
> > > about it.
> right , that's about it.
>
> >  also, the correct format for OSX is GL_BGRA_EXT. i don't
> as i read from GemPixUtil.h (changes by tigital)
> const int chRed = 1;
> const int chGreen = 2;
> const int chBlue = 3;
> const int chAlpha = 0;
>
> this really looks like something ARGB (but you are right, this is not ABGR)
>
> > > think the one you have above even exists.  anyway i will just ifdef
> however, my nvidia'ized gl.h says
> #define Gl_ABGR_EXT 0x800
>
> > > out the changes so the object has no effect again.
> > >
> > > cgc
>
> anyhow, for some personal reasons i'd like to have colour-space conversions.
> to give them not too much room, would something like [pix_convert] (or
> [pix_colourspace] be ok for everybody ?
> anybody refusing to test them ?
>
>
> mfg.a.srd
> IOhannes
>