gd: added input addon

addons/guide/inputs/guide_input_action.gd

@@ -0,0 +1,59 @@
+## An input that mirrors the action's value while the action is triggered.
+@tool
+class_name GUIDEInputAction
+extends GUIDEInput
+
+## The action that this input should mirror. This is live tracked, so any change in
+## the action will update the input.
+@export var action:GUIDEAction:
+	set(value):
+		if value == action:
+			return
+		action = value
+		emit_changed()	
+
+func _begin_usage():
+	if is_instance_valid(action):
+		action.triggered.connect(_on)
+		action.completed.connect(_off)
+		action.ongoing.connect(_off)
+		if action.is_triggered():
+			_on()
+			return
+	# not triggered or no action.
+	_off()
+	
+	
+func _end_usage():
+	if is_instance_valid(action):
+		action.triggered.disconnect(_on)
+		action.completed.disconnect(_off)
+		action.ongoing.disconnect(_off)
+
+
+func _on() -> void:
+	# on is only called when the action is actually existing, so this is
+	# always not-null here
+	_value = action.value_axis_3d
+	
+func _off() -> void:
+	_value = Vector3.ZERO	
+	
+	
+func is_same_as(other:GUIDEInput) -> bool:
+	return other is GUIDEInputAction and other.action == action
+
+
+func _to_string():
+	return "(GUIDEInputAction: " + str(action) + ")"
+
+func _editor_name() -> String:
+	return "Action"
+	
+	
+func _editor_description() -> String:
+	return "An input that mirrors the action's value while the action is triggered."
+	
+
+func _native_value_type() -> GUIDEAction.GUIDEActionValueType:
+	return GUIDEAction.GUIDEActionValueType.AXIS_3D