Android: drive animation frames from the display vsync - #12702
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The event loop capped the poll timeout at a hardcoded 10ms while an animation runs. On a 120Hz display that misses every second vsync, so inertia scrolling drops from 120 to 60fps. Post frame callbacks to the Choreographer from a dedicated helper thread and wake the event loop at each vsync, so the frame rate follows the refresh rate. The thread runs the Choreographer on its own looper to keep its POLL_CALLBACK, which android-activity logs as a spurious error, off the main loop. A fixed 10ms poll remains as a fallback when the thread is unavailable. Fixes: #12407
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Interesting idea to just use poll_once() followed by main_waker.wake() to trigger the redraw. It's a bit obscure for my taste, but I think this should work just fine :)
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The event loop capped the poll timeout at a hardcoded 10ms while an animation runs. On a 120Hz display that misses every second vsync, so inertia scrolling drops from 120 to 60fps.
Post frame callbacks to the Choreographer from a dedicated helper thread and wake the event loop at each vsync, so the frame rate follows the refresh rate. The thread runs the Choreographer on its own looper to keep its POLL_CALLBACK, which android-activity logs as a spurious error, off the main loop. A fixed 10ms poll remains as a fallback when the thread is unavailable.
Fixes: #12407