Screen brightness setting not honored (OS X 10.11)

[quantizor]

I have the screen brightness slider all the way up and if I click it with the mouse, the brightness is correctly applied. However, if I close the game and reopen it, the slider is at the same position, but brightness dials down significantly. It only fixes itself if I click the slider knob again.

 Model Name:    MacBook Pro
 Model Identifier:  MacBookPro11,5
 Processor Name:    Intel Core i7
 Processor Speed:   2.5 GHz
 Number of Processors:  1
 Total Number of Cores: 4
 L2 Cache (per Core):   256 KB
 L3 Cache:  6 MB
 Memory:    16 GB
 Boot ROM Version:  MBP114.0172.B07
 SMC Version (system):  2.30f2

 Chipset Model: AMD Radeon R9 M370X
 Type:  GPU
 Bus:   PCIe
 PCIe Lane Width:   x8
 VRAM (Total):  2048 MB
 Vendor:    ATI (0x1002)
 Device ID: 0x6821
 Revision ID:   0x0083
 ROM Revision:  113-C5670E-777
 gMux Version:  4.0.20 [3.2.8]
 EFI Driver Version:    01.00.777

[quantizor]

This happens with or without automatic screen brightness turned on in the OS X Display settings

[NuclearMonster]

Are you using a test build? If not, upgrade: http://ioquake3.org/get-it/test-builds/

[quantizor]

I am, latest test build.

[nhoda]

I'm experiencing the same issue. I wrote about it here: http://community.ioquake.org/t/gamma-issue-on-mac/634

Some relevant details from my posts:

If I happen to set my resolution to 1280x800 LOWDPI before running ioquake3 (which is only possible using a 3rd party app like QuickRes) then the problem does not occur.

The problem does not occur with the opengl2 renderer.

Updating SDL to the latest release (2.0.4) doesn't fix the problem.

Strangest of all, calling SDL_SetWindowGammaRamp() with the table returned by SDL_GetWindowGammaRamp() corrects the brightness so it's not as though the gamma table is being changed somehow after vid_restart.

[nhoda]

A workaround is to set r_ignorehwgamma to 1 in the game console. You lose control over the brightness but on my system this gives a reasonable brightness level.

It seems OS X maintains gamma tables for each currently open application and switches the graphics device gamma table each time you switch between applications. My conjecture is that the OS is switching to some other application's gamma table after ioquake3 performs the graphics mode change and this is what's causing the brightness to go down.

[winny-]

I think this issue is affecting Linux. I'm running ArchLinux kernel 4.8.6-1-ARCH ioquake3 ioq3 1.36_GIT_1c1e1f6-2016-11-01 client (Nov 10 2016) with an AMD card using the open source drivers.

Does the Screen Brightness GUI setting work or is there a cvar we should be changing?

[MAN-AT-ARMS]

Try r_overbrightbits, r_mapoverbrightbits, and r_intensity instead of r_gamma.

[perepicornell]

Try r_overbrightbits, r_mapoverbrightbits, and r_intensity instead of r_gamma.

Thanks, setting r_overbrightbits to 0 apparently solved it (I had it at 1)