Gamma settings for brightness and contrast

[foft]

I'd like to use the gamma settings for in-game brightness/contrast. Currently the op app for setting gamma only has a gui mode. So I'm wondering:


i) Is there a way of setting gamma from userspace without that app?


ii) Is there any potential for damaging the LCD with bad gamma settings?


iii) Is this a bad idea for any other reason (other than trashing user settings)?


Thanks,


Mark

 

[notaz]

In SZ 1.52 you can do something like system("sudo -n /usr/pandora/scripts/op_gamma.sh 1.0") to change gamma in DSS (OMAP's display controller), and ".../op_gamma.sh 0" to go back to user defaults.


Changing gamma in LCD itself is not available for user apps at the moment (don't know if we really need that and how it's to be interfaced if we provided it).


Edit: updated http://pandorawiki.org/Kernel_interface#gamma

 

[foft]

Well I was thinking that it could be used for brightness and contrast in gemrb by adjusting the overall level and slope shape/steepness respectively. By default it calls SDL gamma which does not visibly do anything.


I guess the alternative is to post-process the display, but that looks trickier.


Great that there is some control for this now via the op_gamma command. Will give it a try.


What is the distinction between LCD gamma and DSS gamma? The program that allows setting the level visually is great but I'm not clear which one that is setting.

 

[foft]

Just wanted to say that I tried out the op_gamma command suggested and its great. Many thanks

 

[atari_afternoon]

Thanks from me, too

sudo -n /usr/pandora/scripts/op_gamma.sh 2.0   (tried around a bit and took 2.0)

works better for me outside in indirect stronger spring sunlight