🚀 go-pugleaf

On Tue, 18 Nov 1997 11:23:53 -0600, Steve Baker <sbaker@link.com>
wrote:

>Michael Harrison wrote:
>> 
>> I hope you'll pardon these two newbie questions, but since I'm new to
>> OpenGL...
>> 
>> I am trying to add gamma correction to our opengl renderer and I
>> haven't found a good way to do this.  For our software renderer I
>> simply change the current palette but under OpenGL I'm running in
>> 16bit color mode and don't actually have a palette.
>> 
>> I also need to add color alpha-blending (say, to make every specified
>> rendered poly a little more red or green or whatever).  With a
>> palette, it's simple.
>
>Gamma correction is not an issue for OpenGL - it's a function of
>your windowing system. The problem is that OpenGL only operates
>in the domain of a single window - and Gamma correction must be
>applied to the entire screen (with most existing hardware
>implementations).

Unfortunately I live in the realm where most users don't understand
this or just can't change the gamma on their systems.  Because of this
I need a gamma control (really just a brightness control) in my
program so they can lighten what may be a dark image on their system.

If I can't affect the gamma (brightness) of the final output with I'll
just have to live with that.

Any ideas on the color mixing?  I could put an alpha poly over the
entire viewing area but that seems particularly inelegant.


  Michael S. Harrison
  http://www.dragonseye.com
  michaelh@(see above line)

* The opinions expressed here are those of my iguana
* and I never know what he's going to say next.