Add chasing functionality to the bat

AI/HurtBox.gd

@@ -0,0 +1,11 @@
+extends Area2D
+
+export(bool) var hit_effect = true
+
+const HitEffect = preload("res://Effects/HitEffect.tscn")
+
+func _on_HurtBox_area_entered(_hitbox):
+	if hit_effect:
+		var effect = HitEffect.instance()
+		get_tree().current_scene.add_child(effect)
+		effect.global_position = global_position

AI/PlayerDetectionZone.gd

@@ -0,0 +1,15 @@
+extends Area2D
+
+var player = null
+
+
+func _on_PlayerDetectionZone_body_entered(body):
+	player = body
+
+
+func _on_PlayerDetectionZone_body_exited(_body):
+	player = null
+
+
+func is_player_detected():
+	return player != null

AI/PlayerDetectionZone.tscn

@@ -0,0 +1,12 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://AI/PlayerDetectionZone.gd" type="Script" id=1]
+
+[node name="PlayerDetectionZone" type="Area2D"]
+collision_layer = 0
+collision_mask = 2
+script = ExtResource( 1 )
+
+[node name="CollisionShape2D" type="CollisionShape2D" parent="."]
+[connection signal="body_entered" from="." to="." method="_on_PlayerDetectionZone_body_entered"]
+[connection signal="body_exited" from="." to="." method="_on_PlayerDetectionZone_body_exited"]

Effects/HitEffect.tscn

@@ -0,0 +1,26 @@
+[gd_scene load_steps=6 format=2]
+
+[ext_resource path="res://Effects/HitEffect.png" type="Texture" id=1]
+[ext_resource path="res://Effects/Effects.gd" type="Script" id=2]
+
+[sub_resource type="AtlasTexture" id=1]
+atlas = ExtResource( 1 )
+region = Rect2( 0, 0, 24, 24 )
+
+[sub_resource type="AtlasTexture" id=2]
+atlas = ExtResource( 1 )
+region = Rect2( 24, 0, 24, 24 )
+
+[sub_resource type="SpriteFrames" id=3]
+animations = [ {
+"frames": [ SubResource( 1 ), SubResource( 2 ) ],
+"loop": false,
+"name": "animate",
+"speed": 10.0
+} ]
+
+[node name="HitEffect" type="AnimatedSprite"]
+frames = SubResource( 3 )
+animation = "animate"
+offset = Vector2( 0, -8 )
+script = ExtResource( 2 )

Enemies/Bat.gd

@@ -3,12 +3,61 @@ extends KinematicBody2D
 const DeathEffect = preload("res://Effects/EnemyDeathEffect.tscn")
 
 var knockback = Vector2.ZERO
+var velocity = Vector2.ZERO
+
 onready var stats = $Stats
+onready var player_detector = $PlayerDetectionZone
+onready var sprite = $AnimatedSprite
+onready var original_position = global_position
+
+export(int) var acceleration = 300
+export(int) var max_speed = 300
+export(int) var friction = 200
+
+enum {
+	IDLE,
+	MOVE,
+	CHASE,
+	MOVE_BACK
+}
+
+onready var state = IDLE
 
 func _physics_process(delta):
 	knockback = knockback.move_toward(Vector2.ZERO, 200 * delta)
 	knockback = move_and_slide(knockback)
 
+	match state:
+		IDLE:
+			velocity = velocity.move_toward(Vector2.ZERO, friction)
+			seek_player()
+
+		MOVE_BACK:
+			# TODO: Navigation here
+			pass
+
+		MOVE:
+			pass
+		CHASE:
+			var player = player_detector.player
+			if player != null:
+				var direction = (player.global_position - global_position).normalized()
+				velocity = velocity.move_toward(direction * max_speed, acceleration * delta)
+				sprite.flip_h = velocity.x < 0
+			else:
+				state = IDLE
+
+	velocity = move_and_slide(velocity)
+
+func around_the_original_position():
+	return abs(original_position.x - global_position.x) < 5 and abs(original_position.y - global_position.y) < 5
+
+
+func seek_player():
+	if player_detector.is_player_detected():
+		state = CHASE
+
+
 func _on_HurtBox_area_entered(area):
 	stats.health -= area.damage
 	knockback = area.knockback_vector * 120

Enemies/Bat.tscn

@@ -1,10 +1,11 @@
-[gd_scene load_steps=14 format=2]
+[gd_scene load_steps=16 format=2]
 
 [ext_resource path="res://Shadows/SmallShadow.png" type="Texture" id=1]
 [ext_resource path="res://Enemies/Bat.png" type="Texture" id=2]
 [ext_resource path="res://AI/HurtBox.tscn" type="PackedScene" id=3]
 [ext_resource path="res://Enemies/Bat.gd" type="Script" id=4]
 [ext_resource path="res://AI/Stats.tscn" type="PackedScene" id=5]
+[ext_resource path="res://AI/PlayerDetectionZone.tscn" type="PackedScene" id=6]
 
 [sub_resource type="AtlasTexture" id=1]
 atlas = ExtResource( 2 )
@@ -41,9 +42,14 @@ radius = 3.92309
 radius = 5.875
 height = 0.75
 
+[sub_resource type="CircleShape2D" id=9]
+radius = 46.4887
+
 [node name="Bat" type="KinematicBody2D"]
 collision_layer = 16
 script = ExtResource( 4 )
+acceleration = 200
+max_speed = 50
 
 [node name="AnimatedSprite" type="AnimatedSprite" parent="."]
 frames = SubResource( 6 )
@@ -68,7 +74,15 @@ shape = SubResource( 8 )
 
 [node name="Stats" parent="." instance=ExtResource( 5 )]
 max_health = 2
+
+[node name="PlayerDetectionZone" parent="." instance=ExtResource( 6 )]
+
+[node name="CollisionShape2D" parent="PlayerDetectionZone" index="0"]
+modulate = Color( 0.654902, 0.192157, 0.192157, 0.298039 )
+shape = SubResource( 9 )
 [connection signal="area_entered" from="HurtBox" to="." method="_on_HurtBox_area_entered"]
 [connection signal="no_health" from="Stats" to="." method="_on_Stats_no_health"]
 
 [editable path="HurtBox"]
+
+[editable path="PlayerDetectionZone"]