further elaboration on bullets

systems/bullets/actions/bullet_action.gd

@@ -0,0 +1,12 @@
+@abstract
+class_name BulletAction
+extends Resource
+
+
+## Performs the action on a given [Bullet].
+func perform(bullet: Bullet) -> void:
+	_perform(bullet)
+
+
+## Called to perform the action on a given [Bullet].
+@abstract func _perform(bullet: Bullet) -> void

systems/bullets/actions/bullet_action.gd.uid

@@ -0,0 +1 @@
+uid://mivkgn34ox41

systems/bullets/actions/despawn_action.gd

@@ -0,0 +1,7 @@
+class_name DespawnAction
+extends BulletAction
+## Removes and recycles the [Bullet] when triggered.
+
+
+func _perform(bullet: Bullet) -> void:
+	bullet.recycle()

systems/bullets/actions/despawn_action.gd.uid

@@ -0,0 +1 @@
+uid://pn143vuxc7wp

systems/bullets/actions/multi_action.gd

@@ -0,0 +1,12 @@
+class_name MultiAction
+extends BulletAction
+## Performs a set of [BulletAction]s in order when triggered.
+
+
+## [BulletAction]s to perform when triggered.
+@export var actions: Array[BulletAction]
+
+
+func _perform(bullet: Bullet) -> void:
+	for action in actions:
+		action.perform(bullet)

systems/bullets/actions/multi_action.gd.uid

@@ -0,0 +1 @@
+uid://mair8nsxn7lp

systems/bullets/actions/spawn_set_action.gd

@@ -0,0 +1,26 @@
+class_name SpawnSetAction
+extends BulletAction
+## Spawns a new [BulletSet] at the [Bullet]'s position when triggered.
+
+
+## The [BulletPreset] to use for the spawned [BulletSet].
+@export var preset: BulletPreset
+
+## If [code]true[/code], the spawned [BulletSet] will be rotated to face the
+## [Bullet]'s direction.
+@export var match_direction: bool = false
+
+## If [code]true[/code], the spawned [BulletSet] will be added as a child of
+## the [Bullet]'s parent [BulletSet]. If [code]false[/code], it will be added
+## as a child of that [BulletSet]'s parent [Node].
+@export var local_coords: bool = false
+
+
+func _perform(bullet: Bullet) -> void:
+	var bullet_set = BulletSet.new()
+	bullet_set.preset = preset
+	bullet_set.global_position = bullet.global_position
+	if local_coords:
+		bullet.get_parent().add_child(bullet_set)
+	else:
+		bullet.get_parent().get_parent().add_child(bullet_set)

systems/bullets/actions/spawn_set_action.gd.uid

@@ -0,0 +1 @@
+uid://oug6n1t6tnor

systems/bullets/behaviors/bullet_behavior.gd

@@ -3,10 +3,30 @@ class_name BulletBehavior
 extends Resource
 
 
-## Called when a bullet is spawned with this behavior in order to set up
-## behavior-specific state.
-@warning_ignore("unused_parameter")
-func init_bullet(bullet: Bullet) -> void: pass
+## Performs behavior-specific initialization for a [Bullet].
+func init_bullet(bullet: Bullet) -> void:
+	bullet.recycled.connect(deinit_bullet.bind(bullet), CONNECT_ONE_SHOT)
+	_init_bullet(bullet)
 
-## Called to process a tick of a bullet's movement.
-@abstract func process_bullet(bullet: Bullet, delta: float) -> void
+
+## Cleans up behavior-specific state for a [Bullet].
+func deinit_bullet(bullet: Bullet) -> void:
+	_deinit_bullet(bullet)
+
+
+## Processes one tick of a [Bullet]'s movement.
+func process_bullet(bullet: Bullet, delta: float) -> void:
+	_process_bullet(bullet, delta)
+
+
+## Called when a [Bullet] is spawned with this behavior in order to set up
+## behavior-specific state.
+@abstract func _init_bullet(bullet: Bullet) -> void
+
+
+## Called when a [Bullet] is recycled in order to clean up behavior-specific state.
+@abstract func _deinit_bullet(bullet: Bullet) -> void
+
+
+## Called to process a tick of a [Bullet]'s movement.
+@abstract func _process_bullet(bullet: Bullet, delta: float) -> void

systems/bullets/behaviors/simple_linear_behavior.gd

@@ -9,7 +9,41 @@ extends BulletBehavior
 ## Rate at which the bullet will speed up.
 @export_custom(0, "suffix:px/s²") var acceleration: float = 0.0
 
+## Speed will be clamped between [member min_speed] and [member max_speed].
+@export_custom(0, "suffix:px/s") var min_speed: float = -INF
+## Speed will be clamped between [member min_speed] and [member max_speed].
+@export_custom(0, "suffix:px/s") var max_speed: float = INF
 
-func process_bullet(bullet: Bullet, delta: float) -> void:
-	var speed = initial_speed + acceleration * bullet.time_elapsed
-	bullet.position += bullet.direction * speed * delta
+@export_group("Actions", "action_")
+@export var action_speed_clamped: BulletAction
+
+
+var _bullet_data: Dictionary[Bullet, Data] = {}
+
+
+func _init_bullet(bullet: Bullet) -> void:
+	var data = Data.new()
+	data.speed = initial_speed
+	_bullet_data[bullet] = data
+
+
+func _deinit_bullet(bullet: Bullet) -> void:
+	_bullet_data.erase(bullet)
+
+
+func _process_bullet(bullet: Bullet, delta: float) -> void:
+	if not _bullet_data.has(bullet):
+		return
+	var data = _bullet_data[bullet]
+	data.speed += acceleration * delta
+	if not data.already_clamped and (data.speed <= min_speed or data.speed >= max_speed):
+		data.already_clamped = true
+		if action_speed_clamped:
+			action_speed_clamped.perform(bullet)
+	data.speed = clampf(data.speed, min_speed, max_speed)
+	bullet.position += bullet.direction * data.speed * delta
+
+
+class Data:
+	var speed: float
+	var already_clamped: bool = false

systems/bullets/bullet.gd

@@ -4,6 +4,10 @@ class_name Bullet
 extends Area2D
 
 
+## Emitted whenever a bullet is recycled.
+signal recycled()
+
+
 ## The number of bullets to allocate at startup.
 const INITIAL_ALLOCATED_BULLETS: int = 2000
 
@@ -51,9 +55,10 @@ static func create(
 	direction: Vector2 = Vector2.RIGHT,
 	face_direction: bool = false,
 ) -> Bullet:
-	var bullet: Bullet = _cached_bullets.pop_back()
-	if not bullet:
-		bullet = Bullet.new()
+	#var bullet: Bullet = _cached_bullets.pop_back()
+	#if not bullet:
+		#bullet = Bullet.new()
+	var bullet := Bullet.new()
 	
 	bullet.texture = texture
 	bullet.hitbox_size = hitbox_size
@@ -67,8 +72,11 @@ static func create(
 ## Removes the bullet from the scene tree and returns it to the bullet cache to be
 ## re-used later.
 func recycle() -> void:
-	get_parent().remove_child(self)
-	_cached_bullets.append(self)
+	#if is_inside_tree():
+		#get_parent().remove_child(self)
+	#_cached_bullets.append(self)
+	queue_free()
+	recycled.emit()
 
 
 static func _static_init() -> void:

systems/bullets/bullet_set.gd

@@ -12,12 +12,11 @@ func _ready() -> void:
 
 
 func _physics_process(delta: float) -> void:
+	if get_child_count() == 0:
+		queue_free()
 	for bullet in get_children():
 		if bullet is Bullet:
 			preset.behavior.process_bullet(bullet, delta)
-		else:
-			push_error("BulletSet does not support having non-bullet children. Removing child: ", bullet)
-			bullet.queue_free()
 
 
 func add_bullet(bullet: Bullet) -> void:

systems/bullets/spawn_patterns/line_pattern.gd

@@ -0,0 +1,26 @@
+class_name LinePattern
+extends BulletSpawnPattern
+
+
+@export var bullet_count: int
+@export var line_width: float
+@export_custom(0, "direction") var line_normal: Vector2 = Vector2.RIGHT
+
+
+func spawn_bullets(bullet_set: BulletSet, preset: BulletPreset) -> void:
+	for i in bullet_count:
+		var bullet = Bullet.create(
+			preset.textures.pick_random(),
+			preset.hitbox_size,
+			line_normal,
+			preset.face_direction
+		)
+		
+		var line = line_normal.orthogonal()
+		var weight = float(i) / float(bullet_count - 1)
+		weight -= 0.5
+		if bullet_count == 1:
+			weight = 0.0
+		bullet.position = line * weight * line_width
+		
+		bullet_set.add_bullet(bullet)

systems/bullets/spawn_patterns/line_pattern.gd.uid

@@ -0,0 +1 @@
+uid://d238qii8i2byl