[Bf-committers] Where did OpenGL dither go?

[Mike Erwin]

Hey guys,
I'll ask tomorrow at work, for the Mac ATI at least. What is it supposed to
look like relative to the picture you posted?
--Mike

On Thursday, June 6, 2013, Ton Roosendaal wrote:

> Hi,
>
> Yes of course that's it... 12 or 16 bits color displays had it. A decade
> ago!
> In the SGI days, many systems did double-buffer by halving the color space
> to 2x12 bits, dithered too.
>
> Nevertheless, for 24 bits "true color" it would look nicer too :)
>
> -Ton-
>
> --------------------------------------------------------
> Ton Roosendaal  -  ton at blender.org <javascript:;>   -   www.blender.org
> Chairman Blender Foundation - Producer Blender Institute
> Entrepotdok 57A  -  1018AD Amsterdam  -  The Netherlands
>
>
>
> On 6 Jun, 2013, at 14:10, Brecht Van Lommel wrote:
>
> > I can't find good info on it either, maybe it was only ever used for
> > OpenGL color index mode or displays with less than 8 bits per color
> > channel?
> >
> > The dither implementation is not specified by the OpenGL
> > specification, and it's valid to not do any dithering at all.
> >
> > On Thu, Jun 6, 2013 at 12:58 PM, Ton Roosendaal <ton at blender.org<javascript:;>>
> wrote:
> >> Hi all,
> >>
> >> Someone pointed me at the banding, visible in shaded 3d viewports with
> greyscales.
> >> None of the systems I tried (mac nvidia, mac ati, linux nvidia) shows
> any dither in the viewport... and there's nothing in the code pointing at
> being disabled.
> >>
> >> I checked it with a print in the graded backdrop drawing:
> >> printf("dither is %d\n", glIsEnabled(GL_DITHER));
> >>
> >> And it says it's on.
> >>
> >> Screenie, with expanded color range to see the banding:
> >> http://www.pasteall.org/pic/52953
> >>
> >> Shouldn't it show a nice stipple pattern? I recall this, but more like
> from 10 years ago or so :)
> >>
> >> Googling about it didn't give me info about this feature being dropped
> in drivers nowadays.
> >>
> >> -Ton-
>


-- 
Mike Erwin
musician, naturalist, pixel pusher, hacker extraordinaire