knockback; base enemy scene; police van

enemies/enemy.gd

@@ -0,0 +1,64 @@
+class_name PoliceCar
+extends CharacterBody3D
+
+const FRAME_IDXS := 10
+
+@export var dot_curve: Curve
+@export var max_speed := 8.
+@export var health := 10.
+@export var knockback_mul := 1.
+
+var frame_idx := 0
+var frame_count := 0
+
+var knockback := Vector3.ZERO
+
+func exp_lerp(a: Variant, b: Variant, decay: float, dt: float) -> Variant:
+	return lerp(a, b, 1 - exp(-decay * dt))
+
+func _ready() -> void:
+	frame_idx = randi() % FRAME_IDXS
+
+func _update_nav_agent() -> void:
+	%NavAgent.target_position = Player.instance.global_position
+
+func _process_movement(delta: float) -> void:
+	var dir := global_position.direction_to(%NavAgent.get_next_path_position())
+	dir.y = 0
+
+	var dot := dir.dot(velocity.normalized())
+	var dot_power := dot_curve.sample(dot)
+	velocity += dir * 8. * delta * dot_power
+	velocity = velocity.limit_length(max_speed)
+
+func _process(delta: float) -> void:
+	frame_count = (frame_count + 1) % FRAME_IDXS
+	if frame_count == frame_idx:
+		_update_nav_agent()
+
+	if knockback.length() < 0.1:
+		_process_movement(delta)
+		rotation.y = Vector2(velocity.x, -velocity.z).angle()
+		position.y = 0.01
+	else:
+		velocity = knockback
+		knockback = exp_lerp(knockback, Vector3.ZERO, 15., delta)
+
+	move_and_slide()
+	
+
+func hit(proj: Node3D, damage: float) -> bool:
+	health -= damage
+	if health <= 0:
+		queue_free()
+	else:
+		if proj is PlayerProjectile:
+			knockback = proj.velocity * 2. * knockback_mul * proj.knockback_mul
+
+	return true
+
+
+func _on_hurtbox_body_entered(body: Node3D) -> void:
+	if body is Player:
+		body.damage(self)
+