Implement demo for separation and cohesion

project/demos/group_behaviors/GroupBehaviorsDemo.tscn

@@ -0,0 +1,11 @@
+[gd_scene load_steps=3 format=2]
+
+[ext_resource path="res://demos/group_behaviors/Member.tscn" type="PackedScene" id=1]
+[ext_resource path="res://demos/group_behaviors/Spawner.gd" type="Script" id=2]
+
+[node name="GroupBehaviorsDemo" type="Node2D"]
+
+[node name="Spawner" type="Node2D" parent="."]
+position = Vector2( 397, 207 )
+script = ExtResource( 2 )
+member = ExtResource( 1 )

project/demos/group_behaviors/Member.gd

@@ -0,0 +1,51 @@
+extends KinematicBody2D
+
+
+var agent: = GSTSteeringAgent.new()
+var separation: GSTSeparation
+var cohesion: GSTCohesion
+var proximity: GSTRadiusProximity
+var blend: = GSTBlend.new(agent)
+var acceleration: = GSTTargetAcceleration.new()
+
+var _radius: float
+var _color: = Color.red
+var _velocity: = Vector2()
+
+onready var shape: = $CollisionShape2D
+
+
+func _ready() -> void:
+	_radius = shape.shape.radius
+	_color = Color(rand_range(0.5, 1), rand_range(0.25, 1), rand_range(0, 1))
+	agent.max_linear_acceleration = 7
+	agent.max_linear_speed = 70
+	
+	proximity = GSTRadiusProximity.new(agent, [], 140)
+	separation = GSTSeparation.new(agent, proximity)
+	separation.decay_coefficient = 2000
+	cohesion = GSTCohesion.new(agent, proximity)
+	blend.add(separation, 1.5)
+	blend.add(cohesion, 0.3)
+
+
+func _draw() -> void:
+	draw_circle(Vector2.ZERO, _radius, _color)
+
+
+func _process(delta: float) -> void:
+	update_agent()
+	if blend:
+		acceleration = blend.calculate_steering(acceleration)
+		_velocity = (_velocity + Vector2(acceleration.linear.x, acceleration.linear.y)).clamped(agent.max_linear_speed)
+		move_and_slide(_velocity)
+
+
+func set_neighbors(neighbor: Array) -> void:
+	proximity.agents = neighbor
+
+
+func update_agent() -> void:
+	var current_position: = global_position
+	agent.position.x = current_position.x
+	agent.position.y = current_position.y

project/demos/group_behaviors/Member.tscn

@@ -0,0 +1,12 @@
+[gd_scene load_steps=3 format=2]
+
+[ext_resource path="res://demos/group_behaviors/Member.gd" type="Script" id=1]
+
+[sub_resource type="CircleShape2D" id=1]
+radius = 15.0
+
+[node name="Member" type="KinematicBody2D"]
+script = ExtResource( 1 )
+
+[node name="CollisionShape2D" type="CollisionShape2D" parent="."]
+shape = SubResource( 1 )

project/demos/group_behaviors/Spawner.gd

@@ -0,0 +1,18 @@
+extends Node2D
+
+
+export var member: PackedScene
+
+
+func _ready() -> void:
+	var followers: = []
+	for i in range(19):
+		var follower: = member.instance()
+		add_child(follower)
+		follower.position += Vector2(rand_range(-60, 60), rand_range(-60, 60))
+		followers.append(follower)
+	var agents: = []
+	for i in followers:
+		agents.append(i.agent)
+	for i in followers:
+		i.proximity.agents = agents

project/src/behaviors/GSTBlend.gd

@@ -9,8 +9,8 @@ class_name GSTBlend
 # `GSTSteeringBehavior` and a `weight` key with a value of type float.
 
 
-onready var _behaviors: = []
+var _behaviors: = []
-onready var _accel: = GSTTargetAcceleration.new()
+var _accel: = GSTTargetAcceleration.new()
 
 
 func _init(agent: GSTSteeringAgent).(agent) -> void:

project/src/behaviors/GSTPriority.gd

@@ -4,7 +4,7 @@ class_name GSTPriority
  # acceleration.
 
 
-onready var _behaviors: = []
+var _behaviors: = []
 
 var last_selected_index: int
 var threshold_for_zero: float
@@ -38,7 +38,7 @@ func _calculate_steering(accel: GSTTargetAcceleration) -> GSTTargetAcceleration:
 			var behavior: GSTSteeringBehavior = _behaviors[i]
 			behavior.calculate_steering(accel)
 			
-			if accel.get_squared_magnitude() > threshold_squared:
+			if accel.get_magnitude_squared() > threshold_squared:
 				break
 	else:
 		accel.set_zero()