World-space AABBs of in-flight gestures that have no scene id at all — a drag-to-insert, pre-commit.
Monotonic counter bumped on the same events subscribe fires on.
Ids the in-flight gesture is previewing, so the canvas can resolve each one's preview bounds.
Wider than previewIdsExtra, which honors previewHidesSource: false
because its job is deciding whose committed paint to suppress: a clone
ghost hides nothing yet still proposes content at the drag target.
Fires whenever the above can have changed. See
CanvasHelpers.subscribeGestures for the published guarantee.
Everything
<Canvas>needs to know about in-flight gestures that it can't see for itself.<Canvas>is deliberately dispatcher-agnostic — it owns the union math and theCanvasHelperscontract, but the live gesture state lives in the gesture dispatcher that<SceneCanvas>creates. This is the one seam between them (createGestureSourceinSceneCanvas/dispatcherGestureBounds.tsbuilds it); bare<Canvas>consumers leave it unwired and get the "no gesture in flight" answers.