Resolve pending gameplay tickets

vessels/Fleet.gd

@@ -33,6 +33,11 @@ var fleet_target: Vector2 = Vector2.ZERO
 # travelling along. Zero heading means the fleet is not being steered.
 var anchor: Vector2 = Vector2.ZERO
 var steer_direction: Vector2 = Vector2.ZERO
+# An aimed Propulser burst translates the complete formation as one body.
+var dash_direction: Vector2 = Vector2.ZERO
+var dash_remaining: float = 0.0
+
+const DASH_SPEED: float = 1400.0
 
 
 func _ready() -> void:
@@ -227,12 +232,29 @@ func move_in_direction(direction: Vector2) -> void:
 	steer_direction = direction.normalized()
 
 
+func dash(direction: Vector2, distance: float) -> bool:
+	if direction.length() < 0.001 or distance <= 0.0 or ships.is_empty():
+		return false
+	if dash_remaining <= 0.0:
+		anchor = get_formation_origin()
+	dash_direction = direction.normalized()
+	dash_remaining = distance
+	return true
+
+
+func is_dashing() -> bool:
+	return dash_remaining > 0.0
+
+
 func _process(delta: float) -> void:
 	# #158: a building may pay a local cost out of the hold when the fleet is
 	# actually standing at it, and the autoload has no other way to know
 	# where that is. Written before the early return below - a parked fleet
 	# is exactly the case that matters.
 	GameState.fleet_position = get_centroid()
+	if is_dashing():
+		_advance_dash(delta)
+		return
 	if steer_direction == Vector2.ZERO:
 		return
 	# The anchor - the fleet's formation centre - travels at cruise_speed.
@@ -244,6 +266,29 @@ func _process(delta: float) -> void:
 	_assign_slot_targets()
 
 
+func _advance_dash(delta: float) -> void:
+	var step: float = minf(DASH_SPEED * delta, dash_remaining)
+	var displacement: Vector2 = dash_direction * step
+	dash_remaining -= step
+	anchor += displacement
+	fleet_target += displacement
+	for ship in ships:
+		if not is_instance_valid(ship):
+			continue
+		# Move the hull and its destination together. That preserves every
+		# formation offset and prevents normal steering from trying to "repair"
+		# the burst by pulling ships back toward their pre-dash targets.
+		ship.position += displacement
+		ship.move_target += displacement
+		ship.velocity = Vector2.ZERO
+		ship.fleet_velocity = Vector2.ZERO
+		ship.rotation = dash_direction.angle() + PI / 2.0
+	if dash_remaining <= 0.001:
+		dash_remaining = 0.0
+		if steer_direction != Vector2.ZERO:
+			_assign_slot_targets()
+
+
 func _effective_cruise_speed() -> float:
 	return cruise_speed * GameState.fleet_speed_multiplier