[Openchrome-users] Brightness/contrast controls?

[Jon Nettleton]

On Tue, 2007-05-01 at 22:56 -0300, Gonzalo A. de la Vega wrote:
> On 5/1/07, Andrei Formiga <andrei.formiga at gmail.com> wrote:
>         On 5/1/07, Gonzalo A. de la Vega <gadelavega at gmail.com> wrote:
>         >
>         > I'll share my experience FWIW (I'm a telecom engineer, so my
>         programming
>         > sucks) 
>         > I had a similar problem with my laptop's display, and I
>         ended up "hard"
>         > conding the contrast/brightnes correction into the driver.
>         
>         That's precisely what I'm thinking about doing, for the time
>         being. I 
>         can't wait until the right way is in place. Did you do it for
>         the
>         openchrome drivers? Any pointers for where I should start
>         looking to
>         play with this? Thanks.
> 
> Here is the patch against the latest svn. This is only for 24bpp, you
> can easily figure out where to change it for 16bpp if you need so.
> Note there is no separate brightness/contrast values, but a single
> factor. Maybe you could use a file to store the multiplying factors
> (all 0.75 for me), and change those. To update the B/C, you may use
> xgamma, which calls the function that executes this code.
> 
> 
>         > I found no
>         > "comfortable" way of using any X interface to apply a proper
>         colormap (which 
>         > I believe would be the correct way of doing it), every time
>         I tried to
>         > change the colormap, X complained about me trying to write
>         read only data.
>         > I understand the solution would be a driver specific thing,
>         but I don't know 
>         > how to do this without violating all the X programming
>         rules.
>         >

The question is, is it worth implementing this into a driver option that
can be specified in xorg.conf?  Definitely not the right solution but is
certainly better than hard-coding the driver.  I probably won't commit
it until I talk to some of the other developers, but I might write up a
patch you guys can use to specify in xorg.conf.

Jon