Called exactly once after construction and before the first frame is rendered. Use this to create PIXI/GPU resources and attach display objects to the provided app/stage.
The host is expected to call this once per instance; implementations do not need to be idempotent unless they choose to be.
Arms an animated disposal transition after a delay.
The delay is relative to the call time and is specified in seconds.
Project convention: this is safe to call multiple times; the latest call re-arms the countdown (and typically resets any in-progress disposal transition).
Note: this only schedules the transition. Actual resource cleanup happens via dispose as part of the animation/host disposal flow.
Time from now until disposal starts, in seconds.
Performance: keep this allocation-light; avoid per-frame heavy allocations where possible.
Elapsed time since the previous frame, in seconds.
Absolute time since app start, in milliseconds (monotonic).
Snapshot of current audio analysis/state for this frame.
Extracted music features for this frame.
Implementations must merge this patch with the existing config (e.g. shallow-merge) and handle missing fields safely.
Must not reset unrelated state unless that behavior is explicitly part of the config contract.
After this is called, the instance must not be used again.