HDR support

[musm]

When HDR support is enabled, brightness control on my monitor is disabled.

Instead, the following slider can control brightness of SDR apps, which acts like a 'pseudo' brightness bar.

Twinkle tray's brightness control in this scenario should either

1. Acts as a proxy and adjust the slider shown in the image above.
2. Disable itself

Right now I can mess around with the brightness slier in Twinkle tray, but it looks like it's corrupting my monitors brightness setting (which are disabled) and has the ability to completely turn off my monitor at setting 0%, and in general doesn't look like it's doing the correct thing and possibly corrupting some state. I had to restart my monitor to reset settings back.

[xanderfrangos]

Odd. I have an HDR monitor and the brightness slider works fine. I have no idea what controls that "HDR/SDR" bar and I don't think it affects true HDR content. Only SDR. I would assume the registry controls it, but I can't find any documentation on where/how it's stored.

[musm]

Is your monitor 10-bit? Here are the other setting on that same page

[musm]

This doesn't really help: https://support.microsoft.com/en-us/windows/hdr-and-wcg-color-settings-in-windows-10-2d767185-38ec-7fdc-6f97-bbc6c5ef24e6
Sadly I also wasn't able to find anything in the regsitry.

[xanderfrangos]

I haven't found much on my own either. Without access to a bunch of HDR monitors, I don't know that I'll be able to do much about this. In a future update, I'll allow users to exclude their monitor from Twinkle Tray. So at least HDR displays can be excluded.

If anyone can provide DDC/CI information about their own HDR display, documentation about adjusting HDR programmatically, or a PR for this feature, it would be greatly appreciated.

[drewchurch]

@xanderfrangos I just dug through procmon when making the HDR toggle and can't find anything that stands out.. it's very chatty at about 47k lines in just a few seconds. If there's anything I can look for, LMK.

Also, how can I provide you DDC/CI info? I've got two HDR compatible displays from different major manufacturers.

[catshitz]

relevant issue here: couldn't reset back to normal mode brightness after turning on & off HDR mode (not the windows fake one but the true HDR mode in a game or a movie),
for example, when I finished playing RE3R in true HDR mode, the monitor will automatically come back to normal mode after I shut the game down(let's say the brightness in HDR is 70 and normal mode 20), at first the twinkle-tray doesn't effect anything until you click it on the traybar and call out its panel, then it'll somehow think you'are still in the HDR mode and automatically set your monitor brightness "back" to 70, which really is some flawness that needs to be fixed.

[FlyingFaller]

Also would like to see HDR support added if possible. Makes the app unusable because I like to keep Windows HDR enabled.

[kev007]

I recently upgraded to Windows 11 and the brightness control of my HDR monitor stopped working. As soon as I turn off HDR, it works again. Even the v1.14-beta1 version does not allow the control that the stable version did on Windows 10.

[wywywywy]

Ok I've found the registry key that the setting changes (tested on Win 11).

Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\MonitorDataStore\DELA1E4#G7IYMxgwAAgX_10_07E6_A1\SDRWhiteLevel

The value is from 1000 (0%) to 3500 (50%) to 6000 (100%) in dec.

Once the SystemSettings.exe has changed the registry value, it calls something in D3D12 to actually apply the change.

I hope this is somewhat useful.

[xanderfrangos]

@wywywywy That might actually help. Thanks!

The only HDR display I have at the moment seems to control HDR brightness via DDC/CI, which is not normal. So someone else will have to look into this further for now.

[wywywywy]

It appears that every 1000 equals 80 nit, although I kind of question that because my screen is supposed to be 400 nit max rather than 480 nit.

Anyway I found out how to get the SDR balance through the Win32 API. I think that to be able to set the SDR balance we'll have to make a call to the display driver.

Data structure: https://docs.microsoft.com/en-us/windows/win32/api/wingdi/ns-wingdi-displayconfig_sdr_white_level

Get: https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-displayconfiggetdeviceinfo

Set: https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-displayconfigsetdeviceinfo