2D antialiased graphics using OpenGL

Billy Biggs vektor@dumbterm.net
Thu, 11 Dec 2003 16:34:51 -0600


Martijn Sipkema (msipkema@sipkema-digital.com):

> > > I think windows doesn't use a corrected framebuffer normally, I'm not
> > > sure though, but that doesn't mean we should not either...
> > 
> >   You're trying to politicize gamma correction?
> 
> Well, yes! :)

  Good, glad that's out in the open.  ;-)

  I mean, you make a reasonable argument.  If framebuffers were linear
intensity values rather than voltage values, a lot of things would be
easier, including being able to turn 'naive' hardware implementations of
algorithms such as compositing to be correct.  All of this is true.

  But I don't buy the argument that OpenGL expects a linear framebuffer.
When I specify a colour as an RGB triple in OpenGL, I am pretty sure
that it expects gamma corrected values.  I will try and find some better
references.  I mean, the difference between rendering gradients and
compositing in a non-gamma corrected space and doing the correct
transform are visible and annoying, but not to the casual observer, and
it's expensive to correct in hardware.  Hence, we have the situation we
are currently in, which is not as bad as you make it out to be.

  -Billy