Add onPreUpdate() (tentative name) that runs on bg thread before onUpdate

[AlmasB]

Certain operations, such as AI, particle simulations, Canvas drawings, can hinder onUpdate() performance, thus leading to fps drop in JavaFX. To fix, we can run a single background tick before JavaFX onUpdate().

This needs to be carefully designed, so discussion is welcome.

[AlmasB]

One possible implementation is for GameScene to have a background thread and keep blocked with an AtomicBoolean while the JavaFX onUpdate runs. However, onUpdate still needs to wait for onPreUpdate to finish, which overall may not be a significant gain. Ultimately, it sounds like we are only gaining the time difference between JavaFX tick end and its next tick start.

It could be possible to run them in parallel, but updateList in GameWorld cannot have nested iterators.

[DeathPhoenix22]

Hi Almas,

For my Game, I'll design a special type of service that will allow asynchronous (mainly parallelized) processing. It will basically allow having a Service running 1 tick behind allowing us to gain a full 18 millis extra processing (in 60FPS, for example.)

I've implemented a FogOfWar service that displays really efficiently, but in certain edge cases, it's requiring approximately 10 millis to resolve the situation, leaving only 8 millis for everything else. My goal is to put that process fully parallelized. The first onUpdate will trigger the processing with the known data and place it in a thread. On the next onUpdate call, the thread ".get()" (Future Promise) will hit FPS only if the parallelized treatment isn't finished yet.

Of course, this requires that the processing can run on an independent thread. For example, changing a view must be done in the main Thread (JavaFX limitation).

Hopefully, I'll provide a robust solution and create a PR for this soon.

[AlmasB]

Hi @DeathPhoenix22

Sounds like a good start. Looking forward to seeing the end result.

[DeathPhoenix22]

Hi @AlmasB
I've submitted an AsyncService implementation. If accepted, it would most likely require a small place in the official doc.
In my case, my plan is to make my PathfindingService async & the AI too. The AI will most likely have a special "Offsync" service that will resync only when ready.