Function registerRuntimeScenePostEventsCallback

Register a function to be called each time a scene is stepped (i.e: at every frame), after events are run and before rendering.

This is the recommended way to synchronize state changes with GDevelop's game loop, rather than using browser APIs like requestAnimationFrame. The game engine owns the game loop and controls the order of execution, so browser APIs may not sync reliably with frame timing.

Use case: Implementing trigger-like conditions

When creating conditions that should act as "triggers" (true for one frame, then automatically false), use this callback to reset flags at frame end. This ensures the flag will:

1. Remain true throughout the current frame (so conditions can detect it)
2. Be reset to false before the next frame begins

Why this works reliably

JavaScript is single-threaded, and asynchronous operations (promises, setTimeout, etc.) only execute between frames, never during frame execution. This means:

• A frame runs completely (behaviors update → events run → this callback → render)
• Async operations (like Promise resolutions) run after the frame completes
• If an async operation sets a flag to true, it stays true until this callback resets it at the end of the next frame

Example usage

// In your extension initialization. Only do this once.
gdjs.registerRuntimeScenePostEventsCallback((runtimeScene) => {
  // Reset trigger flags after events have been processed
  myExtension._dataRequestCompleted = false;
});

// When some async operation completes (probably in an action or somewhere else):
doSomething().then((data) => {
  myExtension._dataRequestCompleted = true; // Will be true for one frame
});

// or using await:
const data = await doSomething();
myExtension._dataRequestCompleted = true; // Will be true for one frame
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