extends Node
##
## StudioBus - global, loosely-coupled signal hub.
##
## Every subsystem talks through this bus instead of holding direct references
## to each other. This keeps coupling low (easy to disable a module) and lets
## modules be lazily loaded/unloaded without dangling pointers.
##

# Selection / scene
signal object_selected(node: Node3D)
signal object_deselected()
signal scene_modified()

# Editing
signal brush_changed(brush_id: String)
signal brush_radius_changed(radius: float)
signal brush_strength_changed(strength: float)
signal stroke_begin(world_pos: Vector3)
signal stroke_apply(world_pos: Vector3, delta: Vector3)
signal stroke_end()

# Memory / performance
signal low_memory()
signal fps_throttled(fps: int)

# Simulation
signal sim_toggled(sim_id: String, enabled: bool)
signal sim_settings_changed(sim_id: String, settings: Dictionary)

# Animation
signal timeline_playhead(time: float)
signal keyframe_added(node_path: String, track: String, time: float)
signal playback_state_changed(playing: bool)

# UI
signal panel_toggled(panel_id: String, visible: bool)


var _last_fps_emit := 0.0


func _process(delta: float) -> void:
	# Surface sustained FPS drops so the renderer can throttle (see Step 2.3).
	if delta <= 0.0:
		return
	var fps := int(Engine.get_frames_per_second())
	if fps > 0 and fps < 30:
		_last_fps_emit += delta
		if _last_fps_emit >= 2.0:
			_last_fps_emit = 0.0
			fps_throttled.emit(fps)
	else:
		_last_fps_emit = 0.0