Papay-Shooter/weapons/homing_projectile.gd

extends ExplosiveProjectile
class_name HomingProjectile

var weapon_source: Node
var turn_speed: float = 5.0

var initial_aim_dir: Vector3 = Vector3.ZERO
var cruise_speed: float = 60.0
var ignition_timer: float = 0.5
var ignited: bool = false
var effects_started: bool = false

func _setup_effects() -> void:
	pass # Wait until ignited

func _start_homing_effects() -> void:
	if effects_started: return
	effects_started = true
	
	# Audio
	flight_sound = AudioStreamPlayer3D.new()
	flight_sound.bus = "SFX"
	flight_sound.stream = load("res://assets/sounds/swarm_flight.wav")
	flight_sound.autoplay = true
	if flight_sound.stream is AudioStreamWAV:
		flight_sound.stream.loop_mode = AudioStreamWAV.LOOP_FORWARD
		flight_sound.stream.loop_end = flight_sound.stream.data.size() / 2  # mono 16-bit frames
	flight_sound.unit_size = 6.0
	flight_sound.max_db = 0.0
	flight_sound.max_distance = 45.0
	flight_sound.volume_db = -10.0
	flight_sound.add_to_group("acoustic_occluded")  # muffles behind walls
	add_child(flight_sound)
	flight_sound.play()
	
	# Jet Fire Particles
	jet_sys = GPUParticles3D.new()
	var jet_mat = ParticleProcessMaterial.new()
	jet_mat.direction = Vector3(0, 0, 1)
	jet_mat.spread = 10.0
	jet_mat.initial_velocity_min = 0.5
	jet_mat.initial_velocity_max = 1.0
	jet_mat.gravity = Vector3.ZERO
	
	var jet_mesh = BoxMesh.new()
	jet_mesh.size = Vector3(0.02, 0.02, 0.02)
	var mat = StandardMaterial3D.new()
	mat.albedo_color = Color(1.0, 0.6, 0.0)
	mat.emission_enabled = true
	mat.emission = Color(1.0, 0.5, 0.0)
	jet_mesh.material = mat
	jet_sys.draw_pass_1 = jet_mesh
	jet_sys.process_material = jet_mat
	jet_sys.amount = 16
	jet_sys.lifetime = 0.15
	jet_sys.position = Vector3(0, 0, 0.05)
	add_child(jet_sys)
	
	# Smoke Trail
	smoke_sys = GPUParticles3D.new()
	var smoke_mat = ParticleProcessMaterial.new()
	smoke_mat.direction = Vector3(0, 0, 1)
	smoke_mat.spread = 5.0
	smoke_mat.initial_velocity_min = 0.0
	smoke_mat.initial_velocity_max = 0.2
	smoke_mat.gravity = Vector3(0, 0.5, 0)
	
	var grad = Gradient.new()
	grad.add_point(0.0, Color(0.5, 0.5, 0.5, 0.8))
	grad.add_point(1.0, Color(0.8, 0.8, 0.8, 0.0))
	var grad_tex = GradientTexture1D.new()
	grad_tex.gradient = grad
	smoke_mat.color_ramp = grad_tex
	
	var curve = Curve.new()
	curve.add_point(Vector2(0.0, 1.0))
	curve.add_point(Vector2(1.0, 3.0))
	var curve_tex = CurveTexture.new()
	curve_tex.curve = curve
	smoke_mat.scale_curve = curve_tex
	
	var smoke_mesh = QuadMesh.new()
	smoke_mesh.size = Vector2(0.08, 0.08)
	var s_mat = StandardMaterial3D.new()
	s_mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	s_mat.vertex_color_use_as_albedo = true
	s_mat.albedo_texture = ExplosiveProjectile.get_smoke_texture()
	s_mat.billboard_mode = BaseMaterial3D.BILLBOARD_PARTICLES
	s_mat.billboard_keep_scale = true
	smoke_mesh.material = s_mat
	smoke_sys.draw_pass_1 = smoke_mesh
	smoke_sys.process_material = smoke_mat
	smoke_sys.amount = 32
	smoke_sys.lifetime = 1.0
	smoke_sys.position = Vector3(0, 0, 0.05)
	add_child(smoke_sys)

func _physics_process(delta: float) -> void:
	if not ignited:
		ignition_timer -= delta
		if ignition_timer <= 0.0:
			ignited = true
			drop_gravity = 0.0
			_start_homing_effects()
			
	if ignited and is_instance_valid(weapon_source):
		var target_dir: Vector3 = initial_aim_dir
		var is_painting = false
		var target: Vector3 = Vector3.ZERO
		
		if weapon_source.get("player") and weapon_source.player:
			is_painting = weapon_source.player.synced_is_targeting
			target = weapon_source.player.synced_homing_target_pos
		else:
			is_painting = weapon_source.get("is_targeting")
			if is_painting != null and is_painting:
				target = weapon_source.get("homing_target_pos")
		
		if is_painting and target != Vector3.ZERO:
			target_dir = (target - global_position).normalized()
				
		if target_dir != Vector3.ZERO:
			var current_dir = velocity.normalized()
			var new_dir = current_dir.lerp(target_dir, turn_speed * delta).normalized()
			
			# Accelerate to cruise speed
			var current_speed = velocity.length()
			var new_speed = move_toward(current_speed, cruise_speed, 80.0 * delta)
			velocity = new_dir * new_speed
			
			var up_vec = Vector3.UP
			if abs(new_dir.dot(up_vec)) > 0.99:
				up_vec = Vector3.RIGHT
			transform.basis = Basis.looking_at(new_dir, up_vec)
	
	super._physics_process(delta)