Basic Bat enemy AI

ActionRPG-HeartBeast/Enemies/Bat.gd

@@ -2,13 +2,51 @@ extends KinematicBody2D
 
 const EnemyDeathEffect = preload("res://Effects/EnemyDeathEffect.tscn")
 
-var knockback = Vector2.ZERO
+export var ACCELERATION = 300
+export var MAX_SPEED = 50
+export var FRICTION = 200
 
+enum {
+	IDLE,
+	WANDER,
+	CHASE
+}
+
+var knockback = Vector2.ZERO
+var velocity = Vector2.ZERO
+
+var state = IDLE
+
+onready var sprite = $AnimatedSprite
 onready var stats = $Stats
+onready var playerDetectionZone = $PlayerDetectionZone
 
 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 * delta)
+			seek_player()
+			
+		WANDER:
+			pass
+			
+		CHASE:
+			var player = playerDetectionZone.player
+			if player != null:
+				var direction = (player.global_position - global_position).normalized()
+				velocity = velocity.move_toward(direction * MAX_SPEED, ACCELERATION * delta)
+			else:
+				state = IDLE
+			sprite.flip_h = velocity.x < 0
+			
+	velocity = move_and_slide(velocity)
+		
+func seek_player():
+	if playerDetectionZone.can_see_player():
+		state = CHASE
 
 func _on_Hurtbox_area_entered(area):
 	stats.health -= area.damage

ActionRPG-HeartBeast/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://Enemies/Bat.png" type="Texture" id=1]
 [ext_resource path="res://Shadows/SmallShadow.png" type="Texture" id=2]
 [ext_resource path="res://Overlap/Hurtbox.tscn" type="PackedScene" id=3]
 [ext_resource path="res://Enemies/Bat.gd" type="Script" id=4]
 [ext_resource path="res://Stats.tscn" type="PackedScene" id=5]
+[ext_resource path="res://Enemies/PlayerDetectionZone.tscn" type="PackedScene" id=6]
 
 [sub_resource type="AtlasTexture" id=1]
 atlas = ExtResource( 1 )
@@ -41,6 +42,9 @@ radius = 4.12311
 radius = 7.0
 height = 6.0
 
+[sub_resource type="CircleShape2D" id=9]
+radius = 61.0328
+
 [node name="Bat" type="KinematicBody2D"]
 collision_layer = 16
 script = ExtResource( 4 )
@@ -48,7 +52,7 @@ script = ExtResource( 4 )
 [node name="AnimatedSprite" type="AnimatedSprite" parent="."]
 frames = SubResource( 6 )
 animation = "Fly"
-frame = 4
+frame = 1
 playing = true
 offset = Vector2( 0, -12 )
 
@@ -68,7 +72,14 @@ 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( 1, 1, 1, 0.258824 )
+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"]

ActionRPG-HeartBeast/Enemies/PlayerDetectionZone.gd

@@ -0,0 +1,13 @@
+extends Area2D
+
+var player = null
+
+# Called when the node enters the scene tree for the first time.
+func can_see_player():
+	return player != null
+
+func _on_PlayerDetectionZone_body_entered(body):
+	player = body
+
+func _on_PlayerDetectionZone_body_exited(body):
+	player = null

ActionRPG-HeartBeast/Enemies/PlayerDetectionZone.tscn

@@ -0,0 +1,13 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://Enemies/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"]