Godot Game Loop Waves

# wave_loop_patterns.gd
extends Node

# 1. Background Scene Preloading
# EXPERT NOTE: Prevents frame-stutters when a massive wave or big boss is about to spawn.
func prepare_boss_wave(scene_path: String) -> void:
    ResourceLoader.load_threaded_request(scene_path)

# 2. Defereed Spawning for Physics Safety
# EXPERT NOTE: Ensures physics engines aren't interrupted by mid-frame instantiations.
func spawn_enemy_deferred(scene: PackedScene, spawn_pos: Vector3) -> void:
    var enemy := scene.instantiate() as Node3D
    enemy.position = spawn_pos
    # Safely adds the child at the end of the frame
    call_deferred(&"add_child", enemy)

# 3. Mass Broadcasting to Enemy Groups
# EXPERT NOTE: Instantly commands all mobs on the map to switch behavior states using StringName.
func enrage_active_enemies() -> void:
    get_tree().call_group(&"enemies", &"enter_enrage_mode")

# 4. Asynchronous Navigation Pathfinding
# EXPERT NOTE: Offloads pathfinding calculations to background threads to handle hundreds of agents.
func request_enemy_path(start: Vector3, end: Vector3, callback: Callable) -> void:
    var params := NavigationPathQueryParameters3D.new()
    params.start_position = start
    params.target_position = end
    # Assuming callback takes the result as an argument
    NavigationServer3D.query_path(params, _on_path_result.bind(callback))

func _on_path_result(result: NavigationPathQueryResult3D, callback: Callable) -> void:
    callback.call(result.path)

# 5. Bypassing Nodes for Swarms (Server-Side)
# EXPERT NOTE: Spawns physical bodies directly in the C++ physics server for extreme scale (10,000+ units).
func create_server_only_mob(xform: Transform3D) -> RID:
    var body_rid := PhysicsServer3D.body_create()
    PhysicsServer3D.body_set_mode(body_rid, PhysicsServer3D.BODY_MODE_KINEMATIC)
    PhysicsServer3D.body_set_space(body_rid, get_world_3d().space)
    PhysicsServer3D.body_set_state(body_rid, PhysicsServer3D.BODY_STATE_TRANSFORM, xform)
    return body_rid

# 6. Deep Duplication of Resource Stats
# EXPERT NOTE: Ensures every spawned mob gets a unique copy of the base stats to prevent shared health pools.
@export var base_enemy_stats: Resource
func setup_individual_stats(enemy_node: Node) -> void:
    if enemy_node.has_method(&"set_stats"):
        enemy_node.set_stats(base_enemy_stats.duplicate_deep())

# 7. Optimized Enemy Counting
# EXPERT NOTE: Quickly queries the engine's group count without iterating.
func get_active_enemy_count() -> int:
    return get_tree().get_node_count_in_group(&"enemies")

# 8. Fast MultiMeshInstance Transforms
# EXPERT NOTE: Manipulates thousands of mesh transforms in a single call for minion swarms.
func batch_update_swarm_visuals(multi_mesh: MultiMesh, index: int, xform: Transform3D) -> void:
    multi_mesh.set_instance_transform(index, xform)

# 9. Proper Avoidance Masking
# EXPERT NOTE: Stops swarming enemies from walking inside each other using NavigationServer.
func setup_mob_avoidance(agent_rid: RID, layer: int) -> void:
    NavigationServer3D.agent_set_avoidance_enabled(agent_rid, true)
    NavigationServer3D.agent_set_avoidance_mask(agent_rid, layer)

# 10. Despawning with Screen Notifications
# EXPERT NOTE: Frees engine memory automatically when a wave pushes an enemy out of bounds.
func _on_visible_on_screen_notifier_3d_screen_exited() -> void:
    # Optional logic: only despawn if far enough or certain conditions met
    queue_free()

# wave_manager.gd
# [GDSKILLS] godot-game-loop-waves
# EXPORT_REFERENCE: wave_manager.gd

extends Node

signal wave_started(wave_index: int)
signal wave_cleared(wave_index: int)
signal all_waves_complete()
signal enemy_spawned(enemy: Node)

@export var wave_sequence: Array[WaveResource] = []
@export var auto_start: bool = false

var current_wave_index: int = -1
var active_enemies: Array[Node] = []
var is_spawning: bool = false

func _ready() -> void:
	if auto_start:
		start_next_wave()

func start_next_wave() -> void:
	if current_wave_index + 1 >= wave_sequence.size():
		all_waves_complete.emit()
		return
		
	current_wave_index += 1
	var current_wave = wave_sequence[current_wave_index]
	
	if current_wave.pre_wave_delay > 0:
		await get_tree().create_timer(current_wave.pre_wave_delay).timeout
	
	_trigger_wave(current_wave)

func _trigger_wave(wave: WaveResource) -> void:
	is_spawning = true
	wave_started.emit(current_wave_index)
	
	var spawn_list = []
	for scene in wave.compositions:
		var count = wave.compositions[scene]
		for i in range(count):
			spawn_list.append(scene)
	
	if wave.random_spawning:
		spawn_list.shuffle()
	
	for enemy_scene in spawn_list:
		_spawn_enemy(enemy_scene)
		await get_tree().create_timer(1.0 / wave.spawn_rate).timeout
		
	is_spawning = false

func _spawn_enemy(scene: PackedScene) -> void:
	var enemy = scene.instantiate()
	add_child(enemy)
	active_enemies.append(enemy)
	enemy.tree_exited.connect(_on_enemy_removed.bind(enemy))
	enemy_spawned.emit(enemy)

func _on_enemy_removed(enemy: Node) -> void:
	active_enemies.erase(enemy)
	if active_enemies.is_empty() and not is_spawning:
		wave_cleared.emit(current_wave_index)
		start_next_wave()

# wave_resource.gd
# [GDSKILLS] godot-game-loop-waves
# EXPORT_REFERENCE: wave_resource.gd

extends Resource
class_name WaveResource

@export_group("Wave Metadata")
## The name of the wave for UI or logging.
@export var wave_name: String = "New Wave"
## Time in seconds before this wave starts after the previous one cleared.
@export var pre_wave_delay: float = 3.0

@export_group("Spawn Configuration")
## Dictionary of enemy scenes and their counts.
## Key: PackedScene, Value: int
@export var compositions: Dictionary = {}

## The rate at which enemies spawn (enemies per second).
@export var spawn_rate: float = 1.0

## If true, enemies spawn at random points. If false, they rotate through spawners.
@export var random_spawning: bool = true

# wave_spawner.gd
# [GDSKILLS] godot-game-loop-waves
# EXPORT_REFERENCE: wave_spawner.gd

extends Marker3D

@export var spawn_radius: float = 0.0

func get_spawn_position() -> Vector3:
	if spawn_radius <= 0.0:
		return global_position
	
	var offset = Vector3(
		randf_range(-spawn_radius, spawn_radius),
		0,
		randf_range(-spawn_radius, spawn_radius)
	)
	return global_position + offset

class_name WaveWeightedSpawner
extends Marker3D

## Wave spawner with weighted random enemy selection.
## Ensures wave variety by controlling spawn probabilities.

@export var enemy_scenes: Array[PackedScene] = []
## Parallel array to enemy_scenes. Higher values = higher probability.
@export var spawn_weights: PackedFloat32Array = []
@export var spawn_radius: float = 2.0

var _rng := RandomNumberGenerator.new()

func _ready() -> void:
	_rng.randomize()

## Spawns a randomly selected enemy based on weights.
func spawn_enemy() -> Node3D:
	if enemy_scenes.is_empty() or spawn_weights.size() != enemy_scenes.size():
		push_error("WaveWeightedSpawner: enemy_scenes and spawn_weights must match in size.")
		return null
	
	# Expert weighted selection using RNG.rand_weighted
	var index = _rng.rand_weighted(spawn_weights)
	var enemy = enemy_scenes[index].instantiate() as Node3D
	
	add_child(enemy)
	enemy.global_position = _get_random_pos()
	
	return enemy

func _get_random_pos() -> Vector3:
	var angle = randf() * TAU
	var distance = randf() * spawn_radius
	return global_position + Vector3(cos(angle) * distance, 0, sin(angle) * distance)