add ant gatherer

scripts/units/ant_gatherer.gd

@@ -0,0 +1,77 @@
+extends ControlledUnit
+class_name AntGatherer
+
+enum AntGathererState {
+	WANDERING,
+	MOVING,
+	GATHERING,
+}
+
+var state: AntGathererState = AntGathererState.WANDERING
+
+@onready var gathering: Gathering = $Gathering
+
+
+static func get_cost() -> int:
+	return 15
+
+
+func _ready() -> void:
+	assert(gathering != null, "gathering missing!")
+	super._ready()
+	moving_started.connect(_on_moving_started)
+	moving_ended.connect(_on_moving_ended)
+	nav_agent.navigation_finished.connect(gathering.on_nav_agent_navigation_finished)
+	gathering.initialize(anthill, 8, 0.4, 1)
+	gathering.target_set.connect(_on_gathering_target_set)
+	gathering.stop_gathering.connect(_on_gathering_stop)
+
+
+func _process(delta: float) -> void:
+	super._process(delta)
+	if moving_to_target:
+		state = AntGathererState.MOVING
+
+	_handle_wandering(delta)
+	_handle_gathering()
+
+
+func _interact(with: Interactable) -> void:
+	if with is Honeydew:
+		state = AntGathererState.GATHERING
+		gathering.go_gather(with as Honeydew)
+
+
+func _handle_wandering(delta: float) -> void:
+	if state != AntGathererState.WANDERING:
+		return
+	
+	_wander(delta)
+
+
+func _handle_gathering() -> void:
+	gathering.handle_gathering(state != AntGathererState.GATHERING)
+
+
+func _on_moving_ended() -> void:
+	state = AntGathererState.WANDERING
+
+
+func _on_moving_started() -> void:
+	if state == AntGathererState.GATHERING:
+		gathering.stop_all_gathering()
+	state = AntGathererState.MOVING
+
+
+func _on_gathering_target_set(pos: Vector3) -> void:
+	if state != AntGathererState.GATHERING:
+		return
+
+	if pos != Vector3.ZERO:
+		nav_agent.set_target_position(pos)
+	else:
+		nav_agent.set_target_position(anthill.global_position)
+
+
+func _on_gathering_stop() -> void:
+	state = AntGathererState.WANDERING