Merge pull request #6 from GDQuest/features/final-toys

Add path following and collision avoid toy demos

project/demos/Arrive/ArriveDemo.gd

@@ -2,7 +2,7 @@ extends Node2D
 
 
 export(float, 0, 2000, 40) var max_linear_speed := 800.0 setget set_max_linear_speed
-export(float, 0, 200, 1) var max_linear_acceleration := 80.0 setget set_max_linear_acceleration
+export(float, 0, 200, 2.0) var max_linear_acceleration := 80.0 setget set_max_linear_acceleration
 export(float, 0, 100, 0.1) var arrival_tolerance := 25.0 setget set_arrival_tolerance
 export(float, 0, 500, 10) var deceleration_radius := 125.0 setget set_deceleration_radius
 
@@ -36,34 +36,32 @@ func _draw():
 
 
 func set_arrival_tolerance(value: float) -> void:
+	arrival_tolerance = value
 	if not is_inside_tree():
 		return
 	
-	arrival_tolerance = value
 	arriver.arrive.arrival_tolerance = value
-	update()
 
 
 func set_deceleration_radius(value: float) -> void:
+	deceleration_radius = value
 	if not is_inside_tree():
 		return
 	
-	deceleration_radius = value
 	arriver.arrive.deceleration_radius = value
-	update()
 
 
 func set_max_linear_speed(value: float) -> void:
+	max_linear_speed = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_speed = value
 	arriver.agent.max_linear_speed = value
 
 
 func set_max_linear_acceleration(value: float) -> void:
+	max_linear_acceleration = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_acceleration = value
 	arriver.agent.max_linear_acceleration = value

project/demos/AvoidCollisions/AvoidCollisionsDemo.gd

@@ -0,0 +1,41 @@
+extends Node2D
+
+
+export(float, 0, 2000, 40) var max_linear_speed := 350.0 setget set_max_linear_speed
+export(float, 0, 100, 2) var max_linear_acceleration := 40.0 setget set_max_linear_accel
+export(float, 0, 500, 10) var proximity_radius := 140.0 setget set_proximity_radius
+export var draw_proximity := true setget set_draw_proximity
+
+onready var spawner := $Spawner
+
+
+func set_max_linear_speed(value: float) -> void:
+	max_linear_speed = value
+	if not is_inside_tree():
+		return
+	
+	spawner.set_max_linear_speed(value)
+
+
+func set_max_linear_accel(value: float) -> void:
+	max_linear_acceleration = value
+	if not is_inside_tree():
+		return
+	
+	spawner.set_max_linear_accel(value)
+
+
+func set_proximity_radius(value: float) -> void:
+	proximity_radius = value
+	if not is_inside_tree():
+		return
+	
+	spawner.set_proximity_radius(value)
+
+
+func set_draw_proximity(value: bool) -> void:
+	draw_proximity = value
+	if not is_inside_tree():
+		return
+	
+	spawner.set_draw_proximity(value)

project/demos/AvoidCollisions/AvoidCollisionsDemo.tscn

@@ -0,0 +1,42 @@
+[gd_scene load_steps=5 format=2]
+
+[ext_resource path="res://demos/AvoidCollisions/Spawner.gd" type="Script" id=1]
+[ext_resource path="res://demos/AvoidCollisions/AvoidCollisionsDemo.gd" type="Script" id=2]
+[ext_resource path="res://demos/AvoidCollisions/Avoider.tscn" type="PackedScene" id=3]
+[ext_resource path="res://assets/theme/gdquest.theme" type="Theme" id=4]
+
+[node name="AvoidCollisionsDemo" type="Node2D"]
+script = ExtResource( 2 )
+max_linear_speed = 360.0
+proximity_radius = 100.0
+
+[node name="Spawner" type="Node2D" parent="."]
+script = ExtResource( 1 )
+avoider_template = ExtResource( 3 )
+normal_color = Color( 0.94902, 0.0588235, 0.0588235, 1 )
+highlight_color = Color( 0.0901961, 0.929412, 0.929412, 1 )
+
+[node name="GUI" type="PanelContainer" parent="."]
+margin_right = 1024.0
+margin_bottom = 14.0
+theme = ExtResource( 4 )
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="MarginContainer" type="MarginContainer" parent="GUI"]
+margin_right = 1024.0
+margin_bottom = 116.0
+
+[node name="RichTextLabel" type="RichTextLabel" parent="GUI/MarginContainer"]
+margin_left = 16.0
+margin_top = 16.0
+margin_right = 1008.0
+margin_bottom = 100.0
+rect_min_size = Vector2( 0, 84 )
+bbcode_enabled = true
+bbcode_text = "Avoid Collisions Demo
+Watch each agent try to keep traveling in a particular direction, but prioritize avoiding collisions with other agents."
+text = "Avoid Collisions Demo
+Watch each agent try to keep traveling in a particular direction, but prioritize avoiding collisions with other agents."
+scroll_active = false

project/demos/AvoidCollisions/Avoider.gd

@@ -0,0 +1,95 @@
+extends KinematicBody2D
+
+
+onready var collision := $CollisionShape2D
+onready var agent := GSTSteeringAgent.new()
+onready var proximity := GSTRadiusProximity.new(agent, [], 140)
+onready var avoid := GSTAvoidCollisions.new(agent, proximity)
+onready var target := GSTAgentLocation.new()
+onready var seek := GSTSeek.new(agent, target)
+onready var priority := GSTPriority.new(agent, 0.0001)
+onready var sprite := $Sprite
+
+var draw_proximity: bool
+
+var _boundary_right: float
+var _boundary_bottom: float
+var _radius: float
+var _accel := GSTTargetAcceleration.new()
+var _velocity := Vector2.ZERO
+var _direction := Vector2()
+var _drag: = 0.1
+
+
+func _draw() -> void:
+	if draw_proximity:
+		draw_circle(Vector2.ZERO, proximity.radius, Color(0, 1, 0, 0.1))
+
+
+func _physics_process(delta: float) -> void:
+	_update_agent()
+	_accel = priority.calculate_steering(_accel)
+	_velocity += Vector2(_accel.linear.x, _accel.linear.y)
+	_velocity = _velocity.linear_interpolate(Vector2.ZERO, _drag)
+	_velocity = _velocity.clamped(agent.max_linear_speed)
+	_velocity = move_and_slide(_velocity)
+
+
+func setup(
+			max_linear_speed: float,
+			max_linear_accel: float,
+			proximity_radius: float,
+			boundary_right: float,
+			boundary_bottom: float,
+			draw_proximity: bool,
+			rng: RandomNumberGenerator
+	) -> void:
+	rng.randomize()
+	_direction = Vector2(rng.randf_range(-1, 1), rng.randf_range(-1, 1)).normalized()
+	_update_agent()
+	agent.max_linear_speed = max_linear_speed
+	agent.max_linear_acceleration = max_linear_accel
+	proximity.radius = proximity_radius
+	_boundary_bottom = boundary_bottom
+	_boundary_right = boundary_right
+	_radius = collision.shape.radius
+	agent.bounding_radius = _radius
+	
+	self.draw_proximity = draw_proximity
+	
+	priority.add(avoid)
+	priority.add(seek)
+
+
+func set_proximity_agents(agents: Array) -> void:
+	proximity.agents = agents
+
+
+func set_random_nonoverlapping_position(others: Array, min_distance_from_boundary: float) -> void:
+	var rng := RandomNumberGenerator.new()
+	rng.randomize()
+	var max_tries := max(100, others.size() * others.size())
+	while max_tries >= 0:
+		max_tries -= 1
+		global_position.x = rng.randf_range(
+				min_distance_from_boundary, _boundary_right-min_distance_from_boundary
+		)
+		global_position.y = rng.randf_range(
+				min_distance_from_boundary, _boundary_bottom-min_distance_from_boundary
+		)
+		var done := true
+		for i in range(others.size()):
+			var other: Node2D = others[i]
+			if other.global_position.distance_to(position) <= _radius*2 + min_distance_from_boundary:
+				done = false
+		if done:
+			break
+
+
+func _update_agent() -> void:
+	agent.position.x = global_position.x
+	agent.position.y = global_position.y
+	agent.linear_velocity.x = _velocity.x
+	agent.linear_velocity.y = _velocity.y
+	target.position.x = agent.position.x + _direction.x*_radius
+	target.position.y = agent.position.y + _direction.y*_radius

project/demos/AvoidCollisions/Avoider.tscn

@@ -0,0 +1,17 @@
+[gd_scene load_steps=4 format=2]
+
+[ext_resource path="res://assets/sprites/small_circle.png" type="Texture" id=1]
+[ext_resource path="res://demos/AvoidCollisions/Avoider.gd" type="Script" id=2]
+
+[sub_resource type="CircleShape2D" id=1]
+radius = 16.0
+
+[node name="Avoider" type="KinematicBody2D"]
+script = ExtResource( 2 )
+
+[node name="CollisionShape2D" type="CollisionShape2D" parent="."]
+shape = SubResource( 1 )
+
+[node name="Sprite" type="Sprite" parent="."]
+modulate = Color( 0.94902, 0.211765, 0.0901961, 1 )
+texture = ExtResource( 1 )

project/demos/AvoidCollisions/Spawner.gd

@@ -0,0 +1,65 @@
+extends Node2D
+
+
+export var avoider_template: PackedScene
+export var normal_color := Color()
+export var highlight_color := Color()
+
+var boundaries: Vector2
+
+
+func _ready() -> void:
+	boundaries = Vector2(ProjectSettings["display/window/size/width"],
+			ProjectSettings["display/window/size/height"])
+	var rng: = RandomNumberGenerator.new()
+	var avoiders := []
+	var avoider_agents := []
+	for i in range(60):
+		var avoider := avoider_template.instance()
+		add_child(avoider)
+		avoider.setup(
+				owner.max_linear_speed,
+				owner.max_linear_acceleration,
+				owner.proximity_radius,
+				boundaries.x,
+				boundaries.y,
+				true if i == 0 and owner.draw_proximity else false,
+				rng
+		)
+		avoider_agents.append(avoider.agent)
+		avoider.set_random_nonoverlapping_position(avoiders, 16)
+		avoider.sprite.modulate = normal_color if i != 0 or not owner.draw_proximity else highlight_color
+		avoiders.append(avoider)
+	for child in get_children():
+		child.set_proximity_agents(avoider_agents)
+
+
+func _physics_process(delta: float) -> void:
+	for child in get_children():
+		child.global_position = child.global_position.posmodv(boundaries)
+
+
+func set_max_linear_speed(value: float) -> void:
+	for child in get_children():
+		child.agent.max_linear_speed = value
+
+
+func set_max_linear_accel(value: float) -> void:
+	for child in get_children():
+		child.agent.max_linear_acceleration = value
+
+
+func set_proximity_radius(value: float) -> void:
+	for child in get_children():
+		child.proximity.radius = value
+	get_child(0).update()
+
+
+func set_draw_proximity(value: bool) -> void:
+	var child := get_child(0)
+	child.draw_proximity = value
+	if not value:
+		child.sprite.modulate = normal_color
+	else:
+		child.sprite.modulate = highlight_color
+	child.update()

project/demos/Face/FaceDemo.gd

@@ -5,11 +5,11 @@ onready var player := $Player
 onready var gui := $GUI
 onready var turret := $Turret
 
-export(int, 0, 359) var max_angular_speed := 90 setget set_max_angular_speed
-export(int, 0, 359) var max_angular_accel := 5 setget set_max_angular_accel
-export(int, 0, 180) var align_tolerance := 5 setget set_align_tolerance
-export(int, 0, 359) var deceleration_radius := 45 setget set_deceleration_radius
-export(float, 0, 1000) var player_speed := 600.0 setget set_player_speed
+export(int, 0, 359, 2) var max_angular_speed := 120 setget set_max_angular_speed
+export(int, 0, 359, 2) var max_angular_accel := 10 setget set_max_angular_accel
+export(int, 0, 180, 2) var align_tolerance := 5 setget set_align_tolerance
+export(int, 0, 359, 2) var deceleration_radius := 45 setget set_deceleration_radius
+export(float, 0, 1000, 40) var player_speed := 600.0 setget set_player_speed
 
 
 func _ready() -> void:
@@ -24,40 +24,40 @@ func _ready() -> void:
 
 
 func set_align_tolerance(value: int) -> void:
+	align_tolerance = value
 	if not is_inside_tree():
 		return
 	
-	align_tolerance = value
 	turret.face.alignment_tolerance = deg2rad(value)
 
 
 func set_deceleration_radius(value: int) -> void:
+	deceleration_radius = value
 	if not is_inside_tree():
 		return
 	
-	deceleration_radius = value
 	turret.face.deceleration_radius = deg2rad(value)
 
 
 func set_max_angular_accel(value: int) -> void:
+	max_angular_accel = value
 	if not is_inside_tree():
 		return
 	
-	max_angular_accel = value
 	turret.agent.max_angular_acceleration = deg2rad(value)
 
 
 func set_max_angular_speed(value: int) -> void:
+	max_angular_speed = value
 	if not is_inside_tree():
 		return
 	
-	max_angular_speed = value
 	turret.agent.max_angular_speed = deg2rad(value)
 
 
 func set_player_speed(value: float) -> void:
+	player_speed = value
 	if not is_inside_tree():
 		return
 	
-	player_speed = value
 	player.speed = player_speed

project/demos/Face/Turret.gd

@@ -5,7 +5,7 @@ var face: GSTFace
 var agent := GSTSteeringAgent.new()
 
 var _accel := GSTTargetAcceleration.new()
-var _angular_drag := 0.01
+var _angular_drag := 0.1
 var _cannon: Rect2
 
 onready var collision_shape := $CollisionShape2D

project/demos/FollowPath/Drawer.gd

@@ -0,0 +1,58 @@
+extends Node2D
+
+
+signal path_established(points)
+
+
+var active_points := []
+var drawing := false
+var distance_threshold := 100.0
+
+
+func _unhandled_input(event: InputEvent) -> void:
+	if event is InputEventMouseMotion:
+		if drawing:
+			active_points.append(event.position)
+			update()
+	elif event is InputEventMouseButton:
+		if event.pressed and event.button_index == BUTTON_LEFT:
+			active_points.clear()
+			active_points.append(event.position)
+			drawing = true
+			update()
+		elif not event.pressed:
+			drawing = false
+			if active_points.size() >= 2:
+				_simplify()
+
+
+func _draw() -> void:
+	if drawing:
+		for point in active_points:
+			draw_circle(point, 1, Color.red)
+	else:
+		if active_points.size() > 0:
+			draw_circle(active_points.front(), 2, Color.red)
+			draw_circle(active_points.back(), 2, Color.yellow)
+			for i in range(1, active_points.size()):
+				var start: Vector2 = active_points[i-1]
+				var end: Vector2 = active_points[i]
+				draw_line(start, end, Color.skyblue)
+
+
+func _simplify() -> void:
+	var first: Vector2 = active_points.front()
+	var last: Vector2 = active_points.back()
+	var key := first
+	var simplified_path := [first]
+	for i in range(1, active_points.size()):
+		var point: Vector2 = active_points[i]
+		var distance := point.distance_to(key)
+		if distance > distance_threshold:
+			key = point
+			simplified_path.append(key)
+	active_points = simplified_path
+	if active_points.back() != last:
+		active_points.append(last)
+	update()
+	emit_signal("path_established", active_points)

project/demos/FollowPath/FollowPathDemo.gd

@@ -0,0 +1,71 @@
+extends Node2D
+
+
+export(float, 0, 2000, 40) var max_linear_speed := 600.0 setget set_max_linear_speed
+export(float, 0, 200, 10.0) var max_linear_acceleration := 40.0 setget set_max_linear_acceleration
+export(float, 0, 100, 0.1) var arrival_tolerance := 10.0 setget set_arrival_tolerance
+export(float, 0, 500, 10) var deceleration_radius := 100.0 setget set_deceleration_radius
+export(float, 0, 5, 0.1) var predict_time := 0.3 setget set_predict_time
+export(float, 0, 200, 10.0) var path_offset := 20.0 setget set_path_offset
+
+onready var drawer := $Drawer
+onready var follower := $PathFollower
+
+
+func _ready() -> void:
+	follower.setup(
+			path_offset,
+			predict_time,
+			max_linear_acceleration,
+			max_linear_speed,
+			deceleration_radius,
+			arrival_tolerance
+	)
+
+
+func set_max_linear_speed(value: float) -> void:
+	max_linear_speed = value
+	if not is_inside_tree():
+		return
+	
+	follower.agent.max_linear_speed = value
+
+
+func set_max_linear_acceleration(value: float) -> void:
+	max_linear_acceleration = value
+	if not is_inside_tree():
+		return
+	
+	follower.agent.max_linear_acceleration = value
+
+
+func set_arrival_tolerance(value: float) -> void:
+	arrival_tolerance = value
+	if not is_inside_tree():
+		return
+	
+	follower.follow.arrival_tolerance = value
+
+
+func set_deceleration_radius(value: float) -> void:
+	deceleration_radius = value
+	if not is_inside_tree():
+		return
+	
+	follower.follow.deceleration_radius = value
+
+
+func set_predict_time(value: float) -> void:
+	predict_time = value
+	if not is_inside_tree():
+		return
+	
+	follower.follow.prediction_time = value
+
+
+func set_path_offset(value: float) -> void:
+	path_offset = value
+	if not is_inside_tree():
+		return
+	
+	follower.follow.path_offset = value

project/demos/FollowPath/FollowPathDemo.tscn

@@ -1,3 +1,52 @@
-[gd_scene format=2]
+[gd_scene load_steps=7 format=2]
+
+[ext_resource path="res://demos/FollowPath/Drawer.gd" type="Script" id=1]
+[ext_resource path="res://assets/sprites/small_circle.png" type="Texture" id=2]
+[ext_resource path="res://demos/FollowPath/PathFollower.gd" type="Script" id=3]
+[ext_resource path="res://demos/FollowPath/FollowPathDemo.gd" type="Script" id=4]
+[ext_resource path="res://assets/theme/gdquest.theme" type="Theme" id=5]
+
+[sub_resource type="CircleShape2D" id=1]
+radius = 16.0
 
 [node name="FollowPathDemo" type="Node2D"]
+script = ExtResource( 4 )
+
+[node name="Drawer" type="Node2D" parent="."]
+script = ExtResource( 1 )
+
+[node name="PathFollower" type="KinematicBody2D" parent="."]
+position = Vector2( 512, 300 )
+script = ExtResource( 3 )
+
+[node name="CollisionShape2D" type="CollisionShape2D" parent="PathFollower"]
+shape = SubResource( 1 )
+
+[node name="Sprite" type="Sprite" parent="PathFollower"]
+modulate = Color( 0.960784, 0.231373, 0.0392157, 1 )
+texture = ExtResource( 2 )
+
+[node name="GUI" type="PanelContainer" parent="."]
+margin_right = 1024.0
+margin_bottom = 14.0
+theme = ExtResource( 5 )
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="MarginContainer" type="MarginContainer" parent="GUI"]
+margin_right = 1024.0
+margin_bottom = 116.0
+
+[node name="RichTextLabel" type="RichTextLabel" parent="GUI/MarginContainer"]
+margin_left = 16.0
+margin_top = 16.0
+margin_right = 1008.0
+margin_bottom = 100.0
+rect_min_size = Vector2( 0, 84 )
+bbcode_enabled = true
+bbcode_text = "Follow Path Demo
+Use the mouse to draw a path on screen and watch the [color=red]red \"Agent\"[/color] follow it to the end."
+text = "Follow Path Demo
+Use the mouse to draw a path on screen and watch the red \"Agent\" follow it to the end."
+scroll_active = false

project/demos/FollowPath/PathFollower.gd

@@ -0,0 +1,56 @@
+extends KinematicBody2D
+
+
+onready var agent := GSTSteeringAgent.new()
+onready var path := GSTPath.new([
+		Vector3(global_position.x, global_position.y, 0),
+		Vector3(global_position.x, global_position.y, 0)
+	], true)
+onready var follow := GSTFollowPath.new(agent, path, 0, 0)
+
+var _velocity := Vector2.ZERO
+var _accel := GSTTargetAcceleration.new()
+var _valid := false
+var _drag := 0.1
+
+
+func setup(
+			path_offset: float,
+			predict_time: float,
+			max_accel: float,
+			max_speed: float,
+			decel_radius: float,
+			arrival_tolerance: float
+	) -> void:
+	owner.drawer.connect("path_established", self, "_on_Drawer_path_established")
+	follow.path_offset = path_offset
+	follow.prediction_time = predict_time
+	agent.max_linear_acceleration = max_accel
+	agent.max_linear_speed = max_speed
+	follow.deceleration_radius = decel_radius
+	follow.arrival_tolerance = arrival_tolerance
+
+
+func _physics_process(delta: float) -> void:
+	if _valid:
+		_update_agent()
+		_accel = follow.calculate_steering(_accel)
+		_velocity += Vector2(_accel.linear.x, _accel.linear.y)
+		_velocity = _velocity.linear_interpolate(Vector2.ZERO, _drag)
+		_velocity = _velocity.clamped(agent.max_linear_speed)
+		_velocity = move_and_slide(_velocity)
+
+
+func _update_agent() -> void:
+	agent.position.x = global_position.x
+	agent.position.y = global_position.y
+	agent.linear_velocity.x = _velocity.x
+	agent.linear_velocity.y = _velocity.y
+
+
+func _on_Drawer_path_established(points: Array) -> void:
+	var points3 := []
+	for p in points:
+		points3.append(Vector3(p.x, p.y, 0))
+	path.create_path(points3)
+	_valid = true

project/demos/GroupBehaviors/GroupBehaviorsDemo.gd

@@ -3,12 +3,12 @@ extends Node2D
 
 onready var spawner := $Spawner
 
-export var max_linear_speed := 100.0 setget set_max_linear_speed
-export var max_linear_accel := 25.0 setget set_max_linear_accel
-export var proximity_radius := 140.0 setget set_proximity_radius
-export var separation_decay_coefficient := 2000.0 setget set_separation_decay_coef
-export var cohesion_strength := 0.3 setget set_cohesion_strength
-export var separation_strength := 1.5 setget set_separation_strength
+export(float, 0, 2000, 40.0) var max_linear_speed := 600.0 setget set_max_linear_speed
+export(float, 0, 200, 2.0) var max_linear_accel := 40.0 setget set_max_linear_accel
+export(float, 0, 300, 2.0) var proximity_radius := 140.0 setget set_proximity_radius
+export(float, 0, 10000, 100) var separation_decay_coefficient := 2000.0 setget set_separation_decay_coef
+export(float, 0, 2, 0.1) var cohesion_strength := 0.1 setget set_cohesion_strength
+export(float, 0, 6, 0.1) var separation_strength := 1.5 setget set_separation_strength
 export var show_proximity_radius := true setget set_show_proximity_radius
 
 
@@ -25,56 +25,56 @@ func _ready() -> void:
 
 
 func set_max_linear_speed(value: float) -> void:
+	max_linear_speed = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_speed = value
 	spawner.set_max_linear_speed(value)
 
 
 func set_max_linear_accel(value: float) -> void:
+	max_linear_accel = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_accel = value
 	spawner.set_max_linear_accel(value)
 
 
 func set_proximity_radius(value: float) -> void:
+	proximity_radius = value
 	if not is_inside_tree():
 		return
 	
-	proximity_radius = value
 	spawner.set_proximity_radius(value)
 
 
 func set_show_proximity_radius(value: bool) -> void:
+	show_proximity_radius = value
 	if not is_inside_tree():
 		return
 	
-	show_proximity_radius = value
 	spawner.set_show_proximity_radius(value)
 
 
 func set_separation_decay_coef(value: float) -> void:
+	separation_decay_coefficient = value
 	if not is_inside_tree():
 		return
 	
-	separation_decay_coefficient = value
 	spawner.set_separation_decay_coef(value)
 
 
 func set_cohesion_strength(value: float) -> void:
+	cohesion_strength = value
 	if not is_inside_tree():
 		return
 	
-	cohesion_strength = value
 	spawner.set_cohesion_strength(value)
 
 
 func set_separation_strength(value: float) -> void:
+	separation_strength = value
 	if not is_inside_tree():
 		return
 	
-	separation_strength = value
 	spawner.set_separation_strength(value)

project/demos/GroupBehaviors/GroupBehaviorsDemo.tscn

@@ -1,13 +1,41 @@
-[gd_scene load_steps=4 format=2]
+[gd_scene load_steps=5 format=2]
 
 [ext_resource path="res://demos/GroupBehaviors/Member.tscn" type="PackedScene" id=1]
 [ext_resource path="res://demos/GroupBehaviors/Spawner.gd" type="Script" id=2]
 [ext_resource path="res://demos/GroupBehaviors/GroupBehaviorsDemo.gd" type="Script" id=3]
+[ext_resource path="res://assets/theme/gdquest.theme" type="Theme" id=4]
 
 [node name="GroupBehaviorsDemo" type="Node2D"]
 script = ExtResource( 3 )
+cohesion_strength = 0.2
+separation_strength = 4.5
 
 [node name="Spawner" type="Node2D" parent="."]
 position = Vector2( 512, 300 )
 script = ExtResource( 2 )
 member = ExtResource( 1 )
+
+[node name="GUI" type="PanelContainer" parent="."]
+margin_right = 1024.0
+margin_bottom = 14.0
+theme = ExtResource( 4 )
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
+[node name="MarginContainer" type="MarginContainer" parent="GUI"]
+margin_right = 1024.0
+margin_bottom = 116.0
+
+[node name="RichTextLabel" type="RichTextLabel" parent="GUI/MarginContainer"]
+margin_left = 16.0
+margin_top = 16.0
+margin_right = 1008.0
+margin_bottom = 100.0
+rect_min_size = Vector2( 0, 84 )
+bbcode_enabled = true
+bbcode_text = "Group Behavior Demo
+Each of the \"Agents\" are both attempting to stay separated and within reach of their nearest group's center of mass."
+text = "Group Behavior Demo
+Each of the \"Agents\" are both attempting to stay separated and within reach of their nearest group's center of mass."
+scroll_active = false

project/demos/GroupBehaviors/Member.gd

@@ -40,12 +40,13 @@ func _draw() -> void:
 		draw_circle(Vector2.ZERO, proximity.radius, Color(0, 1, 0, 0.1))
 
 
-func _process(delta: float) -> void:
+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)
 		_velocity += Vector2(acceleration.linear.x, acceleration.linear.y)
+		_velocity = _velocity.linear_interpolate(Vector2.ZERO, 0.1)
 		_velocity = _velocity.clamped(agent.max_linear_speed)
 		move_and_slide(_velocity)
 

project/demos/PursueSeek/BoundaryManager.gd

@@ -1,5 +1,5 @@
 extends Node2D
-# Wraps the ships' positions around the world border, and controls their rendering clones.
+# Wraps the ships' positions around the world border.
 
 
 var _world_bounds: Vector2

project/demos/PursueSeek/Player.gd

@@ -4,7 +4,7 @@ extends KinematicBody2D
 
 onready var agent := GSTSteeringAgent.new()
 
-export var thruster_strength := 250.0
+export var thruster_strength := 175.0
 export var side_thruster_strength := 10.0
 export var max_velocity := 300.0
 export var max_angular_velocity := 2.0

project/demos/PursueSeek/PursueVSSeekDemo.gd

@@ -1,9 +1,9 @@
 extends Node2D
 
 
-export(float, 0, 2000, 40) var max_linear_speed := 200.0 setget set_max_linear_speed
-export(float, 0, 200, 1) var max_linear_accel := 10.0 setget set_max_linear_accel
-export(float, 0, 5, 0.1) var predict_time := 2.0 setget set_predict_time
+export(float, 0, 2000, 40) var max_linear_speed := 120.0 setget set_max_linear_speed
+export(float, 0, 200, 2) var max_linear_accel := 10.0 setget set_max_linear_accel
+export(float, 0, 5, 0.1) var predict_time := 1.0 setget set_predict_time
 
 onready var pursuer := $BoundaryManager/Pursuer
 onready var seeker := $BoundaryManager/Seeker
@@ -15,26 +15,26 @@ func _ready() -> void:
 
 
 func set_max_linear_speed(value: float) -> void:
+	max_linear_speed = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_speed = value
 	pursuer.agent.max_linear_speed = value
 	seeker.agent.max_linear_speed = value
 
 
 func set_max_linear_accel(value: float) -> void:
+	max_linear_accel = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_accel = value
 	pursuer.agent.max_linear_acceleration = value
 	seeker.agent.max_linear_acceleration = value
 
 
 func set_predict_time(value: float) -> void:
+	predict_time = value
 	if not is_inside_tree():
 		return
 	
-	predict_time = value
 	pursuer._behavior.max_predict_time = value

project/demos/PursueSeek/PursueVSSeekDemo.tscn

@@ -12,8 +12,7 @@ script = ExtResource( 4 )
 __meta__ = {
 "_editor_description_": "Toy demo to demonstrate the use of the Pursue contrasted to the more naive Seek steering behavior."
 }
-max_linear_speed = 120.0
-predict_time = 1.0
+max_linear_speed = 200.0
 
 [node name="BoundaryManager" type="Node2D" parent="."]
 script = ExtResource( 3 )

project/demos/PursueSeek/Pursuer.gd

@@ -14,7 +14,7 @@ var _behavior: GSTSteeringBehavior
 var _linear_velocity := Vector2()
 var _linear_drag_coefficient := 0.025
 var _angular_velocity := 0.0
-var _angular_drag := 1.0
+var _angular_drag := 0.1
 
 
 func _ready() -> void:
@@ -22,13 +22,16 @@ func _ready() -> void:
 
 
 func _physics_process(delta: float) -> void:
+	_update_agent()
+	
 	accel = _orient_behavior.calculate_steering(accel)
 	_angular_velocity += accel.angular
 	
-	if _angular_velocity < 0:
-		_angular_velocity += _angular_drag * delta
-	elif _angular_velocity > 0:
-		_angular_velocity -= _angular_drag * delta
+	_angular_velocity = clamp(
+			lerp(_angular_velocity, 0, _angular_drag),
+			-agent.max_angular_speed,
+			agent.max_angular_speed
+	)
 	
 	rotation += _angular_velocity * delta
 	
@@ -37,8 +40,6 @@ func _physics_process(delta: float) -> void:
 	_linear_velocity = _linear_velocity.linear_interpolate(Vector2.ZERO, _linear_drag_coefficient)
 	_linear_velocity = _linear_velocity.clamped(agent.max_linear_speed)
 	_linear_velocity = move_and_slide(_linear_velocity)
-	
-	_update_agent()
 
 
 func setup(predict_time: float, max_linear_speed: float, max_linear_accel: float) -> void:

project/demos/SeekFlee/SeekFleeDemo.gd

@@ -43,10 +43,10 @@ func _ready() -> void:
 
 
 func set_behavior_mode(mode: int) -> void:
+	behavior_mode = mode
 	if not is_inside_tree():
 		return
 	
-	behavior_mode = mode
 	match mode:
 		Mode.SEEK:
 			for child in spawner.get_children():
@@ -57,26 +57,26 @@ func set_behavior_mode(mode: int) -> void:
 
 
 func set_max_linear_speed(value: float) -> void:
+	max_linear_speed = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_speed = value
 	for child in spawner.get_children():
 		child.agent.max_linear_speed = value
 
 
 func set_max_linear_accel(value: float) -> void:
+	max_linear_accel = value
 	if not is_inside_tree():
 		return
 	
-	max_linear_accel = value
 	for child in spawner.get_children():
 		child.agent.max_linear_acceleration = value
 
 
 func set_player_speed(value: float) -> void:
+	player_speed = value
 	if not is_inside_tree():
 		return
 	
-	player_speed = value
 	player.speed = player_speed

project/src/Behaviors/GSTArrive.gd

@@ -1,5 +1,5 @@
-extends GSTSteeringBehavior
 class_name GSTArrive
+extends GSTSteeringBehavior
 # Calculates acceleration to take an agent to its target's location.
 # The calculation will attempt to arrive with zero remaining velocity.
 

project/src/Behaviors/GSTAvoidCollisions.gd

@@ -1,6 +1,6 @@
-extends GSTGroupBehavior
 class_name GSTAvoidCollisions
-# Behavior that steers the agent to avoid obstacles lying in its path, approximated by a sphere.
+extends GSTGroupBehavior
+# Behavior that steers the agent to avoid obstacles lying in its path as approximated by a sphere.
 
 
 var first_neighbor: GSTSteeringAgent

project/src/Behaviors/GSTBlend.gd

@@ -1,5 +1,5 @@
-extends GSTSteeringBehavior
 class_name GSTBlend
+extends GSTSteeringBehavior
 # Blends multiple steering behaviors into one, and returns acceleration combining all of them.
 
 # # Each behavior is associated with a weight - a modifier by which the result will be multiplied by,

project/src/Behaviors/GSTCohesion.gd

@@ -1,5 +1,5 @@
-extends GSTGroupBehavior
 class_name GSTCohesion
+extends GSTGroupBehavior
 # Group behavior that produces linear acceleration that attempts to move the agent towards the
 # center of mass of the agents in the area defined by the defined Proximity.
 

project/src/Behaviors/GSTEvade.gd

@@ -1,5 +1,5 @@
-extends GSTPursue
 class_name GSTEvade
+extends GSTPursue
 # Calculates acceleration to take an agent away from where a target agent will be.
 
 # # The `max_predict_time` variable represents how far ahead to calculate the intersection point.

project/src/Behaviors/GSTFace.gd

@@ -1,5 +1,5 @@
-extends GSTMatchOrientation
 class_name GSTFace
+extends GSTMatchOrientation
 # Calculates angular acceleration to rotate a target to face its target's position.
 # The acceleration will attempt to arrive with zero remaining angular velocity.
 

project/src/Behaviors/GSTFlee.gd

@@ -1,5 +1,5 @@
-extends GSTSeek
 class_name GSTFlee
+extends GSTSeek
 # Calculates acceleration to take an agent directly away from a target agent.
 
 

project/src/Behaviors/GSTFollowPath.gd

@@ -1,12 +1,12 @@
-extends GSTArrive
 class_name GSTFollowPath
+extends GSTArrive
 # Produces a linear acceleration that moves the agent along the specified path.
 
 
 var path: GSTPath
 var path_offset := 0.0
 
-var path_param := {}
+var path_param := {segment_index = 0, distance = 0}
 
 var arrive_enabled := true
 var prediction_time := 0.0
@@ -32,7 +32,7 @@ func _calculate_steering(acceleration: GSTTargetAcceleration) -> GSTTargetAccele
 	
 	var target_position := path.calculate_target_position(path_param, target_distance)
 	
-	if arrive_enabled and path.is_open:
+	if arrive_enabled and path.open:
 		if path_offset >= 0:
 			if target_distance > path.length - deceleration_radius:
 				return _arrive(acceleration, target_position)

project/src/Behaviors/GSTLookWhereYouGo.gd

@@ -1,5 +1,5 @@
-extends GSTMatchOrientation
 class_name GSTLookWhereYouGo
+extends GSTMatchOrientation
 # Calculates an angular acceleration to match an agent's orientation to its direction of travel.
 
 

project/src/Behaviors/GSTMatchOrientation.gd

@@ -1,5 +1,5 @@
-extends GSTSteeringBehavior
 class_name GSTMatchOrientation
+extends GSTSteeringBehavior
 # Calculates an angular acceleration to match an agent's orientation to its target's.
 # The calculation will attempt to arrive with zero remaining angular velocity.
 

project/src/Behaviors/GSTPriority.gd

@@ -1,5 +1,5 @@
-extends GSTSteeringBehavior
 class_name GSTPriority
+extends GSTSteeringBehavior
 # Contains multiple steering behaviors and returns only the result of the first that has a non-zero
  # acceleration.
 

project/src/Behaviors/GSTPursue.gd

@@ -1,5 +1,5 @@
-extends GSTSteeringBehavior
 class_name GSTPursue
+extends GSTSteeringBehavior
 # Calculates acceleration to take an agent to intersect with where a target agent will be.
 
 # # The `max_predict_time` variable represents how far ahead to calculate the intersection point.

project/src/Behaviors/GSTSeek.gd

@@ -1,5 +1,5 @@
-extends GSTSteeringBehavior
 class_name GSTSeek
+extends GSTSteeringBehavior
 # Calculates acceleration to take an agent to a target agent's position as directly as possible
 
 

project/src/Behaviors/GSTSeparation.gd

@@ -1,5 +1,5 @@
-extends GSTGroupBehavior
 class_name GSTSeparation
+extends GSTGroupBehavior
 # Group behavior that produces acceleration repelling from the other neighbors that are in the
 # immediate area defined by the given `GSTProximity`.
 

project/src/GSTPath.gd

@@ -7,7 +7,7 @@ class_name GSTPath
 
 
 var open: bool
-var path_length: float
+var length: float
 
 var _segments: Array
 
@@ -25,10 +25,11 @@ func _init(waypoints: Array, open := false) -> void:
 func create_path(waypoints: Array) -> void:
 	if not waypoints or waypoints.size() < 2:
 		printerr("Waypoints cannot be null and must contain at least two (2) waypoints.")
+		return
 	
 	_segments = []
-	path_length = 0
-	var current: Vector3 = _segments[0]
+	length = 0
+	var current: Vector3 = waypoints.front()
 	var previous: Vector3
 	
 	for i in range(1, waypoints.size(), 1):
@@ -40,12 +41,14 @@ func create_path(waypoints: Array) -> void:
 		else:
 			current = waypoints[0]
 		var segment := GSTSegment.new(previous, current)
-		path_length += segment.length
-		segment.cumulative_length = path_length
+		length += segment.length
+		segment.cumulative_length = length
 		_segments.append(segment)
 
 
 func calculate_distance(agent_current_position: Vector3, path_parameter: Dictionary) -> float:
+	if _segments.size() == 0:
+		return 0.0
 	var smallest_distance_squared: float = INF
 	var nearest_segment: GSTSegment
 	for i in range(_segments.size()):
@@ -53,7 +56,8 @@ func calculate_distance(agent_current_position: Vector3, path_parameter: Diction
 		var distance_squared := _calculate_point_segment_distance_squared(
 				segment.begin,
 				segment.end,
-				agent_current_position)
+				agent_current_position
+			)
 		
 		if distance_squared < smallest_distance_squared:
 			_nearest_point_on_path = _nearest_point_on_segment
@@ -72,12 +76,12 @@ func calculate_distance(agent_current_position: Vector3, path_parameter: Diction
 
 func calculate_target_position(param: Dictionary, target_distance: float) -> Vector3:
 	if open:
-		target_distance = clamp(target_distance, 0, path_length)
+		target_distance = clamp(target_distance, 0, length)
 	else:
 		if target_distance < 0:
-			target_distance = path_length + fmod(target_distance, path_length)
-		elif target_distance > path_length:
-			target_distance = fmod(target_distance, path_length)
+			target_distance = length + fmod(target_distance, length)
+		elif target_distance > length:
+			target_distance = fmod(target_distance, length)
 	
 	var desired_segment: GSTSegment
 	for i in range(_segments.size()):
@@ -86,6 +90,9 @@ func calculate_target_position(param: Dictionary, target_distance: float) -> Vec
 			desired_segment = segment
 			break
 	
+	if not desired_segment:
+		desired_segment = _segments.back()
+	
 	var distance := desired_segment.cumulative_length - target_distance
 	
 	return (