Make boss encounter more dynamic

boss/BossEye.gd

@@ -5,6 +5,8 @@ signal destroyed
 signal health_changed(current: int, maximum: int)
 
 const COMBAT_TARGET = preload("res://core/CombatTarget.gd")
+const IRIS_COLOR := Color(0.25, 0.92, 1.0)
+const PUPIL_COLOR := Color(1.0, 0.9, 0.3)
 
 @export var max_hp: int = 5
 
@@ -69,7 +71,7 @@ func _draw() -> void:
 	var pulse: float = 0.78 + 0.22 * sin(phase * 5.0)
 	draw_set_transform(Vector2.ZERO, 0.0, Vector2(1.0, 0.66))
 	NeonDraw.draw_glowing_circle(self, Vector2.ZERO, 25.0,
-		Color(0.25, 0.92, 1.0), pulse, dark)
+		IRIS_COLOR, pulse, dark)
 	NeonDraw.draw_glowing_circle(self, Vector2.ZERO, 10.0,
-		Color(1.0, 0.9, 0.3), 1.0, dark)
+		PUPIL_COLOR, 1.0, dark)
 	draw_set_transform(Vector2.ZERO, 0.0, Vector2.ONE)

boss/OctopusBoss.gd

@@ -21,12 +21,20 @@ 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
+const ARMOURED_IRIS_COLOR := Color(0.72, 0.22, 1.0)
+const ARMOURED_PUPIL_COLOR := Color(0.18, 1.0, 0.62)
+const EXPOSED_IRIS_COLOR := Color(1.0, 0.56, 0.08)
+const EXPOSED_PUPIL_COLOR := Color(1.0, 0.94, 0.42)
 
 @export var first_wave_delay: float = 1.5
 @export var wave_interval: float = 6.0
 @export var minions_per_wave: int = 7
-@export var laser_interval: float = 3.5
-@export var laser_charge_time: float = 0.85
+@export var laser_interval: float = 2.25
+@export var laser_charge_time: float = 0.7
+@export var move_speed: float = 115.0
+@export var move_acceleration: float = 180.0
+@export var preferred_fleet_range: float = 880.0
+@export var strafe_speed: float = 72.0
 
 var phase: int = Phase.MINION_WAVES
 var wave_timer: float = 0.0
@@ -43,6 +51,7 @@ 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
+var movement_velocity: Vector2 = Vector2.ZERO
 
 
 func _ready() -> void:
@@ -77,6 +86,7 @@ func _process(delta: float) -> void:
 	if phase == Phase.DEFEATED or not combat_active:
 		return
 	animation_phase += delta
+	_move_around_fleet(delta)
 
 	wave_timer -= delta
 	if wave_timer <= 0.0:
@@ -94,6 +104,31 @@ func _process(delta: float) -> void:
 		queue_redraw()
 
 
+func _move_around_fleet(delta: float) -> void:
+	var fleet: Node2D = get_tree().get_first_node_in_group("player_fleet")
+	if fleet == null or fleet.ships.is_empty():
+		movement_velocity = movement_velocity.move_toward(Vector2.ZERO,
+			move_acceleration * delta)
+		return
+	var from_fleet: Vector2 = global_position - fleet.get_centroid()
+	if from_fleet.length_squared() < 1.0:
+		from_fleet = Vector2.UP
+	var away: Vector2 = from_fleet.normalized()
+	# Close or open the range while continuously strafing around the fleet.
+	# Acceleration keeps the large creature drifting rather than snapping when
+	# the player crosses it, and the speed cap makes its orbit predictable.
+	var range_error: float = from_fleet.length() - preferred_fleet_range
+	var radial_speed: float = clampf(range_error * 0.8, -move_speed, move_speed)
+	var desired_velocity: Vector2 = -away * radial_speed \
+		+ away.orthogonal() * strafe_speed
+	if phase == Phase.CORE_EXPOSED:
+		desired_velocity *= 0.7
+	desired_velocity = desired_velocity.limit_length(move_speed)
+	movement_velocity = movement_velocity.move_toward(desired_velocity,
+		move_acceleration * delta)
+	global_position += movement_velocity * delta
+
+
 func spawn_wave() -> void:
 	if not combat_active or phase == Phase.CORE_EXPOSED or phase == Phase.DEFEATED:
 		return
@@ -303,10 +338,10 @@ 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)
+	var core_color := EXPOSED_IRIS_COLOR if core_exposed else ARMOURED_IRIS_COLOR
 	NeonDraw.draw_glowing_circle(self, Vector2.ZERO, 31.0,
 		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)
+		EXPOSED_PUPIL_COLOR if core_exposed else ARMOURED_PUPIL_COLOR,
+		1.0, dark)
 	draw_set_transform(Vector2.ZERO, 0.0, Vector2.ONE)