TowerDefense/Projectiles/Projectile.gd

extends CharacterBody3D
class_name Projectile

const TARGET_ENEMY : int = 1 ## Flag to target enemy
const TARGET_ALLY : int = 2 ## Flag to target ally

const MINIMUN_AREA : float = .1

var speed : int = 20
var isAOE : bool = false
var allowedTargets : int = TARGET_ENEMY
var target : PhysicsBody3D
var damage : int = 1
var enemiesInRange : Array[Enemy]
var allyInRange : Array[Tower]


func _physics_process(delta: float) -> void:
	if is_instance_valid(target):
		velocity = global_position.direction_to(target.global_position) * speed
		look_at(target.global_position)

		move_and_slide()
	else:
		queue_free()


func onBodyEnteredDamageArea(body: Node3D) -> void:
	if isAOE && targetable(body):
		if body is Enemy:
			enemiesInRange.append(body)
		if body is Tower:
			allyInRange.append(body)


func onBodyExitedDamageArea(body: Node3D) -> void:
	if body is Enemy:
		enemiesInRange.erase(body)
	if body is Tower:
		allyInRange.erase(body)


func onBodyCollideWithProjectile(body: Node3D) -> void:
	if body == target:
		resolveDamages()


func targetable(body: Node3D) -> bool:
	if body is Enemy:
		return TARGET_ENEMY & allowedTargets
	if body is Tower:
		return TARGET_ALLY & allowedTargets

	return false


func resolveDamages() -> void:
	for enemy in enemiesInRange:
		enemy.take_damage(damage)
		queue_free()


func loadProjectile(resource : ProjectileResource, startPosition: Vector3, _target: PhysicsBody3D) -> void:
	target = _target
	enemiesInRange.append(target)
	global_position = startPosition
	speed = resource.speed
	isAOE = resource.isAOE
	allowedTargets = resource.allowedTargets
	$Sprite3D.texture = resource.sprite
	if isAOE && resource.damageArea:
		$DamageArea/ProjectileArea.shape = resource.damageArea