Fullscreen mode ignores Windows "Night light" setting

[TrantaLocked]

Quick summary

Windows 10 "Night light" setting not respected by games in fullscreen.

Details

Fullscreen mode ignores the Windows 10 "Night light" setting with newer builds. Testing with Tony Haw's Pro Skater 3. An older build from mid-2020 does respect the Night light setting in fullscreen.

System Configuration:

• Windows 10
• Ryzen 5 7600
• GTX 970

Additional Information (if any):

Does work on older builds

[RadWolfie]

Please provide build hash for mid-2020 that worked for you.

We have confirmation from older Windows 10 build with exclusive full screen mode works fine with the latest, 6f32d89, Cxbx-Reloaded build.

[TrantaLocked]

Please provide build hash for mid-2020 that worked for you.

We have confirmation from older Windows 10 build with exclusive full screen mode works fine with the latest, 6f32d89, Cxbx-Reloaded build.

Version ff4f4f0 April 9th, 2020

[RadWolfie]

I can confirm to reproduce the issue with ff4f4f0 build, yet it seems to be variety depending on the titles.

• Jet Set Radio Future and Grand Theft Auto 3 titles does preserve night light mode with exclusive full screen mode and quit emulation also preserve night light mode too.
• Halo will crash in exclusive full screen mode with a loss of night light mode when back to desktop. My second monitor does continue to use night light mode.

It seems there's an issue with either latest Windows 10 update or graphic card driver. It will be great to confirm from testers using intel or AMD graphic with latest Windows 10 version to this date.

If intel or AMD graphic aren't causing loss of night light mode, then it could be relative to nvidia's driver causing this issue. Or it could be just latest Windows 10 problem.

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I had tested official PC games in exclusive full screen mode to be sure it's not affected only Cxbx-Reloaded. There appear to be a conflict with DirextX9 renderer usage.

• Games using DirectX9 - confirmed loss of night light mode
• Games DirectX11 - night light mode is preserved

[RadWolfie]

I took a look at git blame for possible cause and able to narrow down to specific release.

CI-357948a build is the last known working with night light mode. After it is CI-c89e1ba build which cause the loss of night light mode. So, the issue came from #2104 pull request which is a switch from IDirect3D to IDirect3D9Ex for the device creation. I'm not sure if it's due to displayMode or using IDirect3D9Ex interface.

The issue may has to do with Windows 10's update or graphic driver bug.