Expand and stage boss encounter

boss/OctopusBoss.gd

@@ -9,19 +9,22 @@ const EYE_SCENE: PackedScene = preload("res://boss/BossEye.tscn")
 const MINION_SCENE: PackedScene = preload("res://boss/BossMinion.tscn")
 const RETURN_SCENE: PackedScene = preload("res://boss/BossReturnSignal.tscn")
 const LASER_SCENE: PackedScene = preload("res://enemies/EnemyBigLaserBeam.tscn")
+const COMBAT_TARGET = preload("res://core/CombatTarget.gd")
 
-enum Phase { MINION_WAVES, LASER_STORM, DEFEATED }
+enum Phase { MINION_WAVES, LASER_STORM, CORE_EXPOSED, DEFEATED }
 
 const EYE_COUNT: int = 6
 const PHASE_TWO_EYES: int = 3
 const BODY_RADIUS: float = 86.0
 const TENTACLE_LENGTH: float = 235.0
-const MAX_ACTIVE_MINIONS: int = 8
+const MAX_ACTIVE_MINIONS: int = 16
+const GOLDEN_WAVE_PERIOD: int = 3
+const CORE_MAX_HEALTH: int = 36
 const REDRAW_INTERVAL: float = 1.0 / 12.0
 
 @export var first_wave_delay: float = 1.5
 @export var wave_interval: float = 6.0
-@export var minions_per_wave: int = 5
+@export var minions_per_wave: int = 7
 @export var laser_interval: float = 3.5
 @export var laser_charge_time: float = 0.85
 
@@ -36,7 +39,10 @@ var spawned_minions: Array = []
 var return_signals: Array = []
 var animation_phase: float = 0.0
 var redraw_left: float = 0.0
-var total_max_health: int = 0
+var total_max_health: int = CORE_MAX_HEALTH
+var core_health: int = CORE_MAX_HEALTH
+var core_exposed: bool = false
+var combat_active: bool = true
 
 
 func _ready() -> void:
@@ -68,7 +74,7 @@ func eye_position(index: int) -> Vector2:
 
 
 func _process(delta: float) -> void:
-	if phase == Phase.DEFEATED:
+	if phase == Phase.DEFEATED or not combat_active:
 		return
 	animation_phase += delta
 
@@ -89,16 +95,25 @@ func _process(delta: float) -> void:
 
 
 func spawn_wave() -> void:
+	if not combat_active or phase == Phase.CORE_EXPOSED or phase == Phase.DEFEATED:
+		return
 	var fleet: Node2D = get_tree().get_first_node_in_group("player_fleet")
 	if fleet == null or fleet.ships.is_empty() or get_parent() == null:
 		return
 	_prune_invalid(spawned_minions)
-	var wanted: int = maxi(3,
+	var wanted: int = maxi(5,
 		minions_per_wave - (2 if phase == Phase.LASER_STORM else 0))
 	var count: int = mini(wanted, MAX_ACTIVE_MINIONS - spawned_minions.size())
 	if count <= 0:
 		return
-	var marked_slot: int = wave_index % count
+	# One useful return every third ACTUAL wave. The first contains one so the
+	# mechanic teaches itself immediately; the two red-only waves afterwards
+	# make the gold target an event rather than permanent scenery.
+	var marked_slot: int = wave_index % GOLDEN_WAVE_PERIOD
+	if marked_slot != 0:
+		marked_slot = -1
+	else:
+		marked_slot = wave_index % count
 	for i in range(count):
 		var minion: Area2D = MINION_SCENE.instantiate()
 		minion.marked = i == marked_slot
@@ -108,8 +123,10 @@ func spawn_wave() -> void:
 		var angle: float = TAU * float(i) / float(count) + float(wave_index) * 0.47
 		# Minions are siblings rather than boss children, so account for the
 		# encounter scene's imposing boss scale when placing them off its body.
-		var launch_radius: float = BODY_RADIUS * scale.x + 34.0
-		minion.global_position = global_position + Vector2.from_angle(angle) * launch_radius
+		var launch_direction := Vector2.from_angle(angle)
+		var launch_radius: float = BODY_RADIUS * scale.x + 60.0
+		minion.global_position = global_position + launch_direction * launch_radius
+		minion.expel(launch_direction, (i + wave_index) % 3 == 0)
 		spawned_minions.append(minion)
 	wave_index += 1
 
@@ -140,7 +157,7 @@ func _on_eye_destroyed(_index: int) -> void:
 	eyes_destroyed += 1
 	health_changed.emit(current_health(), max_health())
 	if eyes_destroyed >= EYE_COUNT:
-		_defeat()
+		_expose_core()
 		return
 	if phase == Phase.MINION_WAVES and eyes_destroyed >= PHASE_TWO_EYES:
 		phase = Phase.LASER_STORM
@@ -154,7 +171,7 @@ func _on_eye_health_changed(_current: int, _maximum: int) -> void:
 
 
 func current_health() -> int:
-	var total: int = 0
+	var total: int = core_health
 	for eye in eyes:
 		if is_instance_valid(eye):
 			total += maxi(int(eye.hp), 0)
@@ -187,6 +204,36 @@ func fire_laser_volley() -> void:
 		beam.launch(global_position, toward.rotated(float(spread)))
 
 
+func set_combat_active(active: bool) -> void:
+	combat_active = active
+	if active:
+		wave_timer = first_wave_delay
+		laser_timer = laser_interval
+
+
+func _expose_core() -> void:
+	if core_exposed or phase == Phase.DEFEATED:
+		return
+	core_exposed = true
+	phase = Phase.CORE_EXPOSED
+	COMBAT_TARGET.register(self, COMBAT_TARGET.DANGER_PRIORITY)
+	$CoreCollision.set_deferred("disabled", false)
+	phase_changed.emit(phase)
+	queue_redraw()
+
+
+func take_damage(amount: int) -> bool:
+	if not core_exposed or phase == Phase.DEFEATED:
+		return false
+	core_health = maxi(core_health - maxi(amount, 1), 0)
+	health_changed.emit(current_health(), max_health())
+	if core_health > 0:
+		queue_redraw()
+		return false
+	_defeat()
+	return true
+
+
 func _forget_minion(minion: Node) -> void:
 	spawned_minions.erase(minion)
 
@@ -205,6 +252,9 @@ func _defeat() -> void:
 	if phase == Phase.DEFEATED:
 		return
 	phase = Phase.DEFEATED
+	core_health = 0
+	remove_from_group(COMBAT_TARGET.GROUP)
+	$CoreCollision.set_deferred("disabled", true)
 	for minion in spawned_minions:
 		if is_instance_valid(minion):
 			minion.retire()
@@ -220,6 +270,8 @@ func _defeat() -> void:
 
 func suppress_as_defeated() -> void:
 	phase = Phase.DEFEATED
+	core_health = 0
+	combat_active = false
 	visible = false
 	set_process(false)
 
@@ -251,8 +303,10 @@ func _draw() -> void:
 	# The central eye watches but is armoured; only tentacle eyes opened by a
 	# returning marked minion join the combat-target group.
 	draw_set_transform(Vector2.ZERO, 0.0, Vector2(0.72, 1.0))
+	var core_color := Color(1.0, 0.78, 0.18) if core_exposed \
+		else Color(0.28, 0.92, 1.0)
 	NeonDraw.draw_glowing_circle(self, Vector2.ZERO, 31.0,
-		Color(0.28, 0.92, 1.0), 0.8 + 0.2 * sin(animation_phase * 3.0), dark)
+		core_color, 0.8 + 0.2 * sin(animation_phase * 3.0), dark)
 	NeonDraw.draw_glowing_circle(self, Vector2.ZERO, 12.0,
 		Color(1.0, 0.82, 0.2), 1.0, dark)
 	draw_set_transform(Vector2.ZERO, 0.0, Vector2.ONE)