Make calculate_acceleration return void

This makes the code more in line with GDQuest gdscript guidelines about
 not both transforming state and returning a value.

project/demos/Arrive/Arriver.gd

@@ -12,7 +12,7 @@ var _drag := 0.1
 
 func _physics_process(delta: float) -> void:
 	_update_agent()
-	_accel = arrive.calculate_steering(_accel)
+	arrive.calculate_steering(_accel)
 	_velocity += Vector2(_accel.linear.x, _accel.linear.y)
 	_velocity = _velocity.linear_interpolate(Vector2.ZERO, _drag).clamped(agent.linear_speed_max)
 	_velocity = move_and_slide(_velocity)

project/demos/AvoidCollisions/Avoider.gd

@@ -28,7 +28,7 @@ func _draw() -> void:
 
 func _physics_process(delta: float) -> void:
 	_update_agent()
-	_accel = priority.calculate_steering(_accel)
+	priority.calculate_steering(_accel)
 	_velocity += Vector2(_accel.linear.x, _accel.linear.y)
 	_velocity = _velocity.linear_interpolate(Vector2.ZERO, _drag)
 	_velocity = _velocity.clamped(agent.linear_speed_max)

project/demos/Face/Turret.gd

@@ -19,7 +19,7 @@ func _ready() -> void:
 
 
 func _physics_process(delta: float) -> void:
-	_accel = face.calculate_steering(_accel)
+	face.calculate_steering(_accel)
 	agent.angular_velocity = clamp(
 			agent.angular_velocity + _accel.angular,
 			-agent.angular_speed_max,

project/demos/FollowPath/PathFollower.gd

@@ -34,7 +34,7 @@ func setup(
 func _physics_process(delta: float) -> void:
 	if _valid:
 		_update_agent()
-		_accel = follow.calculate_steering(_accel)
+		follow.calculate_steering(_accel)
 		_velocity += Vector2(_accel.linear.x, _accel.linear.y)
 		_velocity = _velocity.linear_interpolate(Vector2.ZERO, _drag)
 		_velocity = _velocity.clamped(agent.linear_speed_max)

project/demos/GroupBehaviors/Member.gd

@@ -46,7 +46,7 @@ func _physics_process(delta: float) -> void:
 	agent.position.x = global_position.x
 	agent.position.y = global_position.y
 	if blend:
-		acceleration = blend.calculate_steering(acceleration)
+		blend.calculate_steering(acceleration)
 		_velocity += Vector2(acceleration.linear.x, acceleration.linear.y)
 		_velocity = _velocity.linear_interpolate(Vector2.ZERO, 0.1)
 		_velocity = _velocity.clamped(agent.linear_speed_max)

project/demos/PursueSeek/Pursuer.gd

@@ -25,11 +25,11 @@ func _ready() -> void:
 func _physics_process(delta: float) -> void:
 	_update_agent()
 	
-	accel = _behavior.calculate_steering(accel)
+	_behavior.calculate_steering(accel)
 	
 	_direction_face.position = agent.position + accel.linear.normalized()
 	
-	accel = _orient_behavior.calculate_steering(accel)
+	_orient_behavior.calculate_steering(accel)
 	_angular_velocity += accel.angular
 	
 	_angular_velocity = clamp(

project/demos/SeekFlee/Seeker.gd

@@ -25,9 +25,9 @@ func _physics_process(delta: float) -> void:
 	
 	_update_agent()
 	if use_seek:
-		accel = seek.calculate_steering(accel)
+		seek.calculate_steering(accel)
 	else:
-		accel = flee.calculate_steering(accel)
+		flee.calculate_steering(accel)
 	
 	velocity = (velocity + Vector2(accel.linear.x, accel.linear.y)).clamped(agent.linear_speed_max)
 	velocity = move_and_slide(velocity)

project/src/Behaviors/GSTArrive.gd

@@ -19,7 +19,7 @@ func _init(agent: GSTSteeringAgent, target: GSTAgentLocation).(agent) -> void:
 	self.target = target
 
 
-func _arrive(acceleration: GSTTargetAcceleration, target_position: Vector3) -> GSTTargetAcceleration:
+func _arrive(acceleration: GSTTargetAcceleration, target_position: Vector3) -> void:
 	var to_target := target_position - agent.position
 	var distance := to_target.length()
 
@@ -38,8 +38,6 @@ func _arrive(acceleration: GSTTargetAcceleration, target_position: Vector3) -> G
 		acceleration.linear = GSTUtils.clampedv3(desired_velocity, agent.linear_acceleration_max)
 		acceleration.angular = 0
 
-	return acceleration
 
-
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+	_arrive(acceleration, target.position)
-	return _arrive(acceleration, target.position)

project/src/Behaviors/GSTAvoidCollisions.gd

@@ -16,7 +16,7 @@ func _init(agent: GSTSteeringAgent, proximity: GSTProximity).(agent, proximity)
 	pass
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	_shortest_time = INF
 	_first_neighbor = null
 	_first_minimum_separation = 0
@@ -37,8 +37,6 @@ func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAccele
 	acceleration.linear = acceleration.linear.normalized() * -agent.linear_acceleration_max
 	acceleration.angular = 0
 
-	return acceleration
-
 
 # Callback for the proximity to call when finding neighbors. Keeps track of every `neighbor`
 # that was found but only keeps the one the owning agent will most likely collide with.

project/src/Behaviors/GSTBlend.gd

@@ -33,7 +33,7 @@ func get_behavior_at(index: int) -> Dictionary:
 	return {}
 
 
-func _calculate_steering(blended_accel: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(blended_accel: GSTTargetAcceleration) -> void:
 	blended_accel.set_zero()
 
 	for i in range(_behaviors.size()):
@@ -48,5 +48,3 @@ func _calculate_steering(blended_accel: GSTTargetAcceleration) -> GSTTargetAccel
 			-agent.angular_acceleration_max,
 			agent.angular_acceleration_max
 	)
-
-	return blended_accel

project/src/Behaviors/GSTCohesion.gd

@@ -11,14 +11,13 @@ func _init(agent: GSTSteeringAgent, proximity: GSTProximity).(agent, proximity)
 	pass
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	acceleration.set_zero()
 	_center_of_mass = Vector3.ZERO
 	var neighbor_count = proximity._find_neighbors(_callback)
 	if neighbor_count > 0:
 		_center_of_mass *= 1.0 / neighbor_count
 		acceleration.linear = (_center_of_mass - agent.position).normalized() * agent.linear_acceleration_max
-	return acceleration
 
 
 # Callback for the proximity to call when finding neighbors. Adds `neighbor`'s position

project/src/Behaviors/GSTFace.gd

@@ -8,17 +8,16 @@ func _init(agent: GSTSteeringAgent, target: GSTAgentLocation).(agent, target) ->
 	pass
 
 
-func _face(acceleration: GSTTargetAcceleration, target_position: Vector3) -> GSTTargetAcceleration:
+func _face(acceleration: GSTTargetAcceleration, target_position: Vector3) -> void:
 	var to_target := target_position - agent.position
 	var distance_squared := to_target.length_squared()
 
 	if distance_squared < agent.zero_linear_speed_threshold:
 		acceleration.set_zero()
-		return acceleration
 	else:
 		var orientation = GSTUtils.vector3_to_angle(to_target)
-		return _match_orientation(acceleration, orientation)
+		_match_orientation(acceleration, orientation)
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
-	return _face(acceleration, target.position)
+	_face(acceleration, target.position)

project/src/Behaviors/GSTFlee.gd

@@ -7,9 +7,7 @@ func _init(agent: GSTSteeringAgent, target: GSTAgentLocation).(agent, target) ->
 	pass
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	acceleration.linear = (
 			(agent.position - target.position).normalized() * agent.linear_acceleration_max)
 	acceleration.angular = 0
-
-	return acceleration

project/src/Behaviors/GSTFollowPath.gd

@@ -25,7 +25,7 @@ func _init(
 	self.prediction_time = prediction_time
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	var location := (
 			agent.position if prediction_time == 0
 			else agent.position + (agent.linear_velocity * prediction_time))
@@ -38,13 +38,13 @@ func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAccele
 	if is_arrive_enabled and path.is_open:
 		if path_offset >= 0:
 			if target_distance > path.length - deceleration_radius:
-				return _arrive(acceleration, target_position)
+				_arrive(acceleration, target_position)
+				return
 		else:
 			if target_distance < deceleration_radius:
-				return _arrive(acceleration, target_position)
+				_arrive(acceleration, target_position)
+				return
 
 	acceleration.linear = (target_position - agent.position).normalized()
 	acceleration.linear *= agent.linear_acceleration_max
 	acceleration.angular = 0
-
-	return acceleration

project/src/Behaviors/GSTLookWhereYouGo.gd

@@ -8,10 +8,9 @@ func _init(agent: GSTSteeringAgent).(agent, null) -> void:
 	pass
 
 
-func _calculate_steering(accel: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(accel: GSTTargetAcceleration) -> void:
 	if agent.linear_velocity.length_squared() < agent.zero_linear_speed_threshold:
 		accel.set_zero()
-		return accel
 	else:
 		var orientation := GSTUtils.vector3_to_angle(agent.linear_velocity)
-		return _match_orientation(accel, orientation)
+		_match_orientation(accel, orientation)

project/src/Behaviors/GSTMatchOrientation.gd

@@ -20,7 +20,7 @@ func _init(agent: GSTSteeringAgent, target: GSTAgentLocation).(agent) -> void:
 	self.target = target
 
 
-func _match_orientation(acceleration: GSTTargetAcceleration, desired_orientation: float) -> GSTTargetAcceleration:
+func _match_orientation(acceleration: GSTTargetAcceleration, desired_orientation: float) -> void:
 	var rotation := wrapf(desired_orientation - agent.orientation, -PI, PI)
 
 	var rotation_size := abs(rotation)
@@ -43,8 +43,6 @@ func _match_orientation(acceleration: GSTTargetAcceleration, desired_orientation
 
 	acceleration.linear = Vector3.ZERO
 
-	return acceleration
 
-
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+	_match_orientation(acceleration, target.orientation)
-	return _match_orientation(acceleration, target.orientation)

project/src/Behaviors/GSTPriority.gd

@@ -31,7 +31,7 @@ func get_behavior_at(index: int) -> GSTSteeringBehavior:
 	return null
 
 
-func _calculate_steering(accel: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(accel: GSTTargetAcceleration) -> void:
 	var threshold_squared := zero_threshold * zero_threshold
 
 	last_selected_index = -1
@@ -48,5 +48,3 @@ func _calculate_steering(accel: GSTTargetAcceleration) -> GSTTargetAcceleration:
 				break
 	else:
 		accel.set_zero()
-
-	return accel

project/src/Behaviors/GSTPursue.gd

@@ -19,7 +19,7 @@ func _init(
 	self.predict_time_max = predict_time_max
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	var target_position := target.position
 	var distance_squared := (target_position - agent.position).length_squared()
 
@@ -37,8 +37,6 @@ func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAccele
 
 	acceleration.angular = 0
 
-	return acceleration
-
 
 func _get_modified_acceleration() -> float:
 	return agent.linear_acceleration_max

project/src/Behaviors/GSTSeek.gd

@@ -12,9 +12,7 @@ func _init(agent: GSTSteeringAgent, target: GSTAgentLocation).(agent) -> void:
 	self.target = target
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	acceleration.linear = (
 			(target.position - agent.position).normalized() * agent.linear_acceleration_max)
 	acceleration.angular = 0
-
-	return acceleration

project/src/Behaviors/GSTSeparation.gd

@@ -18,11 +18,10 @@ func _init(agent: GSTSteeringAgent, proximity: GSTProximity).(agent, proximity)
 	pass
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	acceleration.set_zero()
 	self._acceleration = acceleration
 	proximity._find_neighbors(_callback)
-	return acceleration
 
 
 # Callback for the proximity to call when finding neighbors. Determines the amount of

project/src/GSTSteeringBehavior.gd

@@ -18,16 +18,13 @@ func _init(agent: GSTSteeringAgent) -> void:
 	self.agent = agent
 
 
-# Returns the `acceleration` modified with the behavior's desired amount of
+# Sets the `acceleration` with the behavior's desired amount of acceleration.
-# acceleration.
+func calculate_steering(acceleration: GSTTargetAcceleration) -> void:
-func calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
 	if is_enabled:
-		return _calculate_steering(acceleration)
+		_calculate_steering(acceleration)
 	else:
 		acceleration.set_zero()
-		return acceleration
 
 
-func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAcceleration:
+func _calculate_steering(acceleration: GSTTargetAcceleration) -> void:
 	acceleration.set_zero()
-	return acceleration