How can I know which window emits the Compositor tick event?

Question

How can I know which window emits the Compositor tick event?

峻魁张 25

I have a program that can open multiple windows, and currently, I use DCompositionWaitForCompositorClock to achieve vertical sync refresh rate. However, how can I make multiple windows synchronize at different refresh rates on different monitors? For example, I have two monitors, the primary monitor running at 60Hz and the secondary monitor running at 120Hz. It seems that DCompositionWaitForCompositorClock only emits tick events when my primary monitor refreshes. Is there a function similar to DCompositionWaitForCompositorClock that I can use to obtain tick events for the corresponding monitor on the secondary display?

峻魁张 25 Reputation points

2024-03-12T08:00:07.9133333+00:00

By the way, DCompositionWaitForCompositorClock is a win11 only feature, is there some api gives the same functionality that works at least on win10?
Xiaopo Yang - MSFT 12,736 Reputation points Microsoft External Staff

2024-03-13T03:27:29.72+00:00

Wait for the compositor clock says that compositor clock can accommodate for Next vertical blank when compositor clock isn't necessarily sourced from the primary display. It seems DCompositionBoostCompositorClock.

When the source of the compositor clock supports Dynamic Refresh Rate (that feature is turned on in advanced display settings; only usable on variable refresh rate displays with support drivers) the system will be able to dynamically switch between two rates.

Have you tried it?

And does the Windows.UI.Composition Namespace work for you?
峻魁张 25 Reputation points

2024-03-13T12:45:38.9233333+00:00

I tried that, and not what I want
Xiaopo Yang - MSFT 12,736 Reputation points Microsoft External Staff

2024-03-14T07:35:20.4933333+00:00

I tried that, and not what I want

Could you provide more information about this? Is the refresh rate boosted?

Boosting compositor clock should be a workaround but note the monitor with 60Hz will not always synchronize with the 120Hz monitor.

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