Added a few new features for FSMs

addons/behaviour_toolkit/finite_state_machine/fsm_transition.gd

@@ -11,21 +11,41 @@ class_name FSMTransition extends BehaviourToolkit
 ## [code]use_event[/code] to true and set the event property to the name
 ## of the event you want to listen for.
 
-
 ## The state to transition to.
 @export var next_state: FSMState:
 	set(value):
 		next_state = value
 		update_configuration_warnings()
 
 @export_category("Transition Logic")
+
+## Always transition, ignoring `is_valid()` or any events.
+@export var always_transition: bool = false:
+	set(value):
+		always_transition = value
+		notify_property_list_changed()
+		update_configuration_warnings()
+
+
+# Rather than using @export on these properties, we include them here so we can show them conditionally.
+func _get_property_list() -> Array[Dictionary]:
+	var property_list: Array[Dictionary] = []
+
+	if not always_transition:
+		property_list.append({"name": "use_event", "type": TYPE_BOOL})
+		property_list.append({"name": "event", "type": TYPE_STRING})
+
+	return property_list
+
+
 ## If true, the FSM will check for the event to trigger the transition.
-@export var use_event: bool = false:
+var use_event: bool = false:
 	set(value):
 		use_event = value
 		update_configuration_warnings()
+
 ## The event that triggers the transition.
-@export var event: String = "":
+var event: String = "":
 	set(value):
 		event = value
 		update_configuration_warnings()
@@ -38,6 +58,9 @@ func _on_transition(_delta: float, _actor: Node, _blackboard: Blackboard) -> voi
 
 ## Evaluates true, if the transition conditions are met.
 func is_valid(_actor: Node, _blackboard: Blackboard) -> bool:
+	if always_transition:
+		return true
+
 	return false
 
 

addons/behaviour_toolkit/finite_state_machine/transitions/fsm_split_transition.gd

@@ -0,0 +1,63 @@
+@tool
+@icon("res://addons/behaviour_toolkit/icons/FSMSplitTransition.svg")
+class_name FSMSplitTransition extends FSMTransition
+
+## The state to transition to.
+@export var next_state_true: FSMState:
+	set(value):
+		next_state_true = value
+		update_configuration_warnings()
+
+@export var next_state_false: FSMState:
+	set(value):
+		next_state_false = value
+		update_configuration_warnings()
+
+# Internal flag that determines which state gets transitioned to
+var _transition_flag: bool
+
+
+# Executed when the transition is taken.
+func _on_transition(_delta: float, _actor: Node, _blackboard: Blackboard) -> void:
+	pass
+
+
+# Always returns true, because this transition always triggers one way or another.
+# Because `get_next_state()` doesn't have access to the actor or blackboard, a flag is
+# set internally here which sets up the next transition.
+func is_valid(actor: Node, blackboard: Blackboard) -> bool:
+	set_transition_flag(actor, blackboard)
+	return true
+
+
+func set_transition_flag(_actor: Node, _blackboard: Blackboard) -> void:
+	pass
+
+
+## Returns which state to transition to, based on internal transition flag set in `set_transition_flag()`.
+func get_next_state() -> FSMState:
+	return next_state_true if _transition_flag else next_state_false
+
+
+# Add custom configuration warnings
+# Note: Can be deleted if you don't want to define your own warnings.
+func _get_configuration_warnings() -> PackedStringArray:
+	var warnings: Array = []
+
+	var parent: Node = get_parent()
+	if not parent is FSMState:
+		warnings.append("FSMSplitTransition should be a child of FSMState.")
+
+	if next_state:
+		warnings.append("FSMSplitTransition has next state; unset and set true and false states.")
+
+	if not next_state_true:
+		warnings.append("FSMSplitTransition has no next state for true.")
+
+	if not next_state_false:
+		warnings.append("FSMSplitTransition has no next state for false.")
+
+	if use_event and event == "":
+		warnings.append("FSMSplitTransition has no event set.")
+
+	return warnings

addons/behaviour_toolkit/icons/FSMSplitTransition.svg.import

@@ -0,0 +1,37 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://c4vs4uicrouno"
+path="res://.godot/imported/FSMSplitTransition.svg-e6773317add235944b13c8c864f570b3.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://addons/behaviour_toolkit/icons/FSMSplitTransition.svg"
+dest_files=["res://.godot/imported/FSMSplitTransition.svg-e6773317add235944b13c8c864f570b3.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
+svg/scale=1.0
+editor/scale_with_editor_scale=false
+editor/convert_colors_with_editor_theme=false

addons/behaviour_toolkit/ui/toolkit_ui.gd

@@ -38,6 +38,7 @@ func _ready():
 	%ButtonAddFSM.connect("pressed", _on_button_pressed.bind(FiniteStateMachine, "FiniteStateMachine"))
 	%ButtonState.connect("pressed", _on_button_pressed.bind(FSMState, "FSMState"))
 	%ButtonTransition.connect("pressed", _on_button_pressed.bind(FSMTransition, "FSMTransition"))
+	%ButtonSplitTransition.connect("pressed", _on_button_pressed.bind(FSMSplitTransition, "FSMSplitTransition"))
 	%ButtonStateIntegratedBT.connect("pressed", _on_button_pressed.bind(FSMStateIntegratedBT, "FSMStateIntegratedBT"))
 	%ButtonStateIntegrationReturn.connect("pressed", _on_button_pressed.bind(FSMStateIntegrationReturn, "FSMStateIntegrationReturn"))
 

addons/behaviour_toolkit/ui/toolkit_ui.tscn

@@ -1,4 +1,4 @@
-[gd_scene load_steps=39 format=3 uid="uid://o16emp4t4wb1"]
+[gd_scene load_steps=40 format=3 uid="uid://o16emp4t4wb1"]
 
 [ext_resource type="Script" path="res://addons/behaviour_toolkit/ui/toolkit_ui.gd" id="1_51rvx"]
 [ext_resource type="Texture2D" uid="uid://boof0yioplbqr" path="res://addons/behaviour_toolkit/icons/FSMState.svg" id="1_hqqj5"]
@@ -26,6 +26,7 @@
 [ext_resource type="Texture2D" uid="uid://b45qiy5niriwu" path="res://addons/behaviour_toolkit/icons/BTLeafPrint.svg" id="10_ji4ht"]
 [ext_resource type="Texture2D" uid="uid://xi8li3jk2vs6" path="res://addons/behaviour_toolkit/icons/BTLeafWait.svg" id="10_n2nk3"]
 [ext_resource type="Texture2D" uid="uid://hn65lqk8tero" path="res://addons/behaviour_toolkit/icons/BTDecoratorRepeat.svg" id="10_nvbp1"]
+[ext_resource type="Texture2D" uid="uid://c4vs4uicrouno" path="res://addons/behaviour_toolkit/icons/FSMSplitTransition.svg" id="10_ypexi"]
 [ext_resource type="Texture2D" uid="uid://cwvb6d7kvo53u" path="res://addons/behaviour_toolkit/icons/BTLeafCall.svg" id="12_axgn0"]
 [ext_resource type="Texture2D" uid="uid://by4ymq46fp1ra" path="res://addons/behaviour_toolkit/icons/BTLeafCondition.svg" id="13_6h0vl"]
 [ext_resource type="Texture2D" uid="uid://ddx7a726xhria" path="res://addons/behaviour_toolkit/icons/BTCompositeIntegration.svg" id="13_gmc6x"]
@@ -187,6 +188,13 @@ layout_mode = 2
 text = "New Transition"
 icon = ExtResource("2_24di4")
 
+[node name="ButtonSplitTransition" type="Button" parent="ScrollContainer/MarginContainer/VBoxContainer/Panel/ScrollContainer/Toolbox/FiniteStateMachine"]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_horizontal = 3
+text = "Split Transition"
+icon = ExtResource("10_ypexi")
+
 [node name="BehaviourTree" type="VBoxContainer" parent="ScrollContainer/MarginContainer/VBoxContainer/Panel/ScrollContainer/Toolbox"]
 unique_name_in_owner = true
 layout_mode = 2

docs/documentation.md

@@ -29,9 +29,11 @@ The node icons where designed/choosen to give you a quick overview of their purp
       - [Signals](#signals)
     - [ FSMState](#-fsmstate)
       - [Methods](#methods-1)
+      - [Extras][#extras]
     - [ FSMTransition](#-fsmtransition)
       - [Properties](#properties-1)
       - [Methods](#methods-2)
+      - [Extras][#extras-1]
 - [Behaviour Tree](#behaviour-tree)
   - [Usage](#usage-1)
   - [Tree Nodes](#tree-nodes)
@@ -109,6 +111,12 @@ This is the base class for all states. On ready, all `FSMTransition` child nodes
 - void `_on_exit(actor: Node, blackboard: Blackboard)`
     - Called when the state is exited.
 
+#### Extras
+There are extra states that you can use out of the box:
+
+- ![PrintOnEnter Icon](../addons/behaviour_toolkit/icons/BTLeafPrint.svg) Print on Enter
+  - Prints a message to the console when entering this state. Very handy for debugging.
+
 
 ### ![FSM Transition Icon](../addons/behaviour_toolkit/icons/FSMTransition.svg) FSMTransition
 This is the base class for all transitions. To implement your logic you can override the `_on_transition` method when extending the node's script. To setup custom conditions you can override the `is_valid` method. If you want to use events to trigger the transition, set `use_event` to `true` and set the `event` property to the name of the event you want to listen for.
@@ -128,6 +136,16 @@ This is the base class for all transitions. To implement your logic you can over
 - bool `is_valid`
     - Should return `true` if the conditions for the transition are met.
 
+#### Extras
+There are a few extra transitions that you can use out of the box:
+
+- ![SplitTransition Icon](../addons/behaviour_toolkit/icons/FSMSplitTransition.svg) Split
+  - Always transition to one of two states, based on a coded boolean check.
+- ![AlwaysTransition Icon](../addons/behaviour_toolkit/icons/AlwaysTransition.svg) Always
+  - Always transition, useful for states that only act once.
+
+Script templates are also available to make it easier to extend the above classes.
+
 
 # Behaviour Tree
 A behavior tree is a mathematical model of plan execution used in computer science, robotics, control systems and video games. They describe switchings between a finite set of tasks in a modular fashion. Their strength comes from their ability to create very complex tasks composed of simple tasks, without worrying how the simple tasks are implemented. ([Wikipedia](https://en.wikipedia.org/wiki/Behavior_tree_(artificial_intelligence,_robotics_and_control)))

examples/fsm_split_transition/fsm_split_transition_example.tscn

@@ -0,0 +1,53 @@
+[gd_scene load_steps=7 format=3 uid="uid://dd1t17mhnvpn4"]
+
+[ext_resource type="Script" path="res://addons/behaviour_toolkit/finite_state_machine/fsm.gd" id="1_ugani"]
+[ext_resource type="Script" path="res://examples/fsm_split_transition/fsm_state_print_counter.gd" id="2_dxxwi"]
+[ext_resource type="Script" path="res://examples/fsm_split_transition/fsm_state_print_on_enter.gd" id="2_s4dqp"]
+[ext_resource type="Script" path="res://examples/fsm_split_transition/fsm_transition_to_finish.gd" id="3_mm16c"]
+[ext_resource type="Script" path="res://examples/fsm_split_transition/fsm_transition_even_or_odd.gd" id="4_kimeb"]
+[ext_resource type="Script" path="res://addons/behaviour_toolkit/finite_state_machine/fsm_transition.gd" id="6_am5vp"]
+
+[node name="SplitTransitionExample" type="Node2D"]
+
+[node name="FiniteStateMachine" type="Node" parent="." node_paths=PackedStringArray("initial_state")]
+script = ExtResource("1_ugani")
+autostart = true
+initial_state = NodePath("PrintCounter")
+
+[node name="PrintCounter" type="Node" parent="FiniteStateMachine"]
+script = ExtResource("2_dxxwi")
+
+[node name="TransitionToFinish" type="Node" parent="FiniteStateMachine/PrintCounter" node_paths=PackedStringArray("next_state")]
+script = ExtResource("3_mm16c")
+next_state = NodePath("../../PrintDone")
+use_event = false
+event = ""
+
+[node name="GoEvenOrOdd" type="Node" parent="FiniteStateMachine/PrintCounter" node_paths=PackedStringArray("next_state_true", "next_state_false")]
+script = ExtResource("4_kimeb")
+next_state_true = NodePath("../../PrintEven")
+next_state_false = NodePath("../../PrintOdd")
+use_event = false
+event = ""
+
+[node name="PrintEven" type="Node" parent="FiniteStateMachine"]
+script = ExtResource("2_s4dqp")
+custom_text = "Even"
+
+[node name="ReturnToStart" type="Node" parent="FiniteStateMachine/PrintEven" node_paths=PackedStringArray("next_state")]
+script = ExtResource("6_am5vp")
+next_state = NodePath("../../PrintCounter")
+always_transition = true
+
+[node name="PrintOdd" type="Node" parent="FiniteStateMachine"]
+script = ExtResource("2_s4dqp")
+custom_text = "Odd"
+
+[node name="ReturnToStart" type="Node" parent="FiniteStateMachine/PrintOdd" node_paths=PackedStringArray("next_state")]
+script = ExtResource("6_am5vp")
+next_state = NodePath("../../PrintCounter")
+always_transition = true
+
+[node name="PrintDone" type="Node" parent="FiniteStateMachine"]
+script = ExtResource("2_s4dqp")
+custom_text = "Done"

examples/fsm_split_transition/fsm_state_print_counter.gd

@@ -0,0 +1,19 @@
+@tool
+extends FSMState
+
+
+# Executes after the state is entered.
+func _on_enter(_actor: Node, _blackboard: Blackboard) -> void:
+	if _blackboard.get_value("counter") == null:
+		_blackboard.set_value("counter", 0)
+
+	var counter: int = _blackboard.get_value("counter")
+	if counter == null:
+		print(0)
+	else:
+		print(counter)
+
+## Executes before the state is exited.
+func _on_exit(_actor: Node, _blackboard: Blackboard) -> void:
+	var counter: int = _blackboard.get_value("counter")
+	_blackboard.set_value("counter", counter + 1)

examples/fsm_split_transition/fsm_state_print_on_enter.gd

@@ -0,0 +1,13 @@
+@tool
+@icon("res://addons/behaviour_toolkit/icons/BTLeafPrint.svg")
+extends FSMState
+
+@export var custom_text: String
+
+
+# Executes after the state is entered.
+func _on_enter(_actor: Node, _blackboard: Blackboard) -> void:
+	if custom_text != "":
+		print(custom_text)
+	else:
+		print("Hello World!")