Re: [GD-Windows] GetDeviceGammaRamp() is lieing to me

[brian h. <bri...@py...>]

Which operating system?

> In my program, I call GetDeviceGammaRamp() to read the user's 
> active gamma settings. Then, if there's not "sufficient" gamma 
> adjustment, I set my own gamma ramp with SetDeviceGammaRamp(). 
> When the program exits, I restore the ramp I read back from 
> GetDeviceGammaRamp() on start-up.
> 
> Unfortunately, it appears that the device is lieing to me. I 
> get the data as such:
> 
>   WORD userRamp[ 768 ];
>   HDC dc = CreateDC( "DISPLAY", 0, 0, 0 );
>   GetDeviceGammaRamp( dc, userRamp );
> 
> What ends up happening is that I always get back some "default" 
> gamma ramp with a little bit of compensation; I apply my own 
> ramp, and then on shutdown I set the ramp "back" to some very 
> low gamma setting.
> 
> If I go into my display control panel settings and crank the 
> gamma way up (both "game gamma" and "desktop gamma"), then 
> starting my program will still retrieve the same "default" gamma 
> ramp, apply its ramp (which is dimmer), and on shutdown, set the 
> screen to a very dim setting.
> 
> This is on a Radeon 9700, though I've heard similar problems 
> from users with nVIDIA hardware as well.
> 
> What's going on?
> 
>                     / h+