Ship Lab: per-vessel research, and the shield vessel

Forgejo #5. A new building gated behind a "Vessel Science" research
node. Its own screen upgrades each vessel type - weapon, movement,
shield and freight - and unlocks the shield vessel, which the ship
crafter can then build.

Vessel research is deliberately NOT more nodes in the mothership tree:
that tree gates what may be built at all and is a strategic spine, while
these are repeatable tuning on vessels already owned. Levels cost
base * (level + 1), so the third point in something is not the price of
the first. Upgrades are read live rather than baked in at build time, so
researching one improves the ships already flying.

The shield is personal, not a bubble: it absorbs a hit that would
destroy the vessel - ships have no health, contact kills - and is then
down until it cycles. Its ring is a NeonPiece child toggled with
`visible` per #10, not a redraw of the hull.

The build menu now holds six entries across three rows, which the #21
repacking already handles.

Enemies still have no weapon, so "blocks shots" has nothing to block
yet; that is filed separately rather than widened into this ticket.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

BuildController.gd

@@ -28,6 +28,20 @@ extends Node2D
 @onready var build_status: Label = get_node("../UI/BuildMenu/StatusLabel")
 @onready var build_extractor_button: IconButton = get_node("../UI/BuildMenu/ExtractorButton")
 @onready var build_hub_button: IconButton = get_node("../UI/BuildMenu/TransportHubButton")
+@onready var build_lab_button: IconButton = get_node("../UI/BuildMenu/ShipLabButton")
+@onready var lab_menu: Control = get_node("../UI/LabMenu")
+@onready var lab_vessel_buttons: Array = [
+	get_node("../UI/LabMenu/VesselA"), get_node("../UI/LabMenu/VesselB"),
+	get_node("../UI/LabMenu/VesselC"),
+]
+@onready var lab_vessel_label: Label = get_node("../UI/LabMenu/VesselLabel")
+@onready var lab_list: Label = get_node("../UI/LabMenu/UpgradeList")
+@onready var lab_detail: Label = get_node("../UI/LabMenu/DetailLabel")
+@onready var lab_status: Label = get_node("../UI/LabMenu/StatusLabel")
+@onready var lab_next_button: IconButton = get_node("../UI/LabMenu/NextButton")
+@onready var lab_buy_button: IconButton = get_node("../UI/LabMenu/BuyButton")
+@onready var lab_close_button: IconButton = get_node("../UI/LabMenu/CloseButton")
+@onready var craft_shield_button: IconButton = get_node("../UI/CraftMenu/ShieldButton")
 @onready var build_menu_entries: Array = [
 	[GameState.BUILDING_MOTHERSHIP, build_mothership_button,
 		get_node("../UI/BuildMenu/MothershipLabel"), get_node("../UI/BuildMenu/MothershipCost")],
@@ -39,7 +53,16 @@ extends Node2D
 		get_node("../UI/BuildMenu/ExtractorLabel"), get_node("../UI/BuildMenu/ExtractorCost")],
 	[GameState.BUILDING_TRANSPORT_HUB, build_hub_button,
 		get_node("../UI/BuildMenu/TransportHubLabel"), get_node("../UI/BuildMenu/TransportHubCost")],
+	[GameState.BUILDING_SHIP_LAB, build_lab_button,
+		get_node("../UI/BuildMenu/ShipLabLabel"), get_node("../UI/BuildMenu/ShipLabCost")],
 ]
+
+# Which vessel the lab screen is showing, and which of its upgrades is
+# selected. The screen steps through one upgrade at a time rather than
+# listing tappable rows: on a phone a row of small hit targets is worse than
+# one big Buy button and a Next.
+var lab_vessel: String = GameState.VESSEL_INTERCEPTOR
+var lab_choice: int = 0
 @onready var planet_field: Node2D = get_node("../PlanetField")
 @onready var info_popup: Control = get_node("../UI/BuildMenu/InfoPopup")
 @onready var info_title: Label = get_node("../UI/BuildMenu/InfoPopup/Panel/TitleLabel")
@@ -92,6 +115,10 @@ const BUILDING_INFO: Dictionary = {
 		"title": "Command Center",
 		"body": "Fly the fleet onto it to drag your fleet into a new formation. Rebuilt fleets keep it.",
 	},
+	GameState.BUILDING_SHIP_LAB: {
+		"title": "Ship Lab",
+		"body": "Fly the fleet onto it to upgrade each vessel type, and to unlock the shield vessel.",
+	},
 	GameState.BUILDING_TRANSPORT_HUB: {
 		"title": "Transport Hub",
 		"body": "Stations transport vessels. They fetch ore from your mothership and deliver it to whichever building is waiting on it.",
@@ -127,6 +154,13 @@ func _ready() -> void:
 	build_command_button.pressed.connect(_on_place_command_center)
 	build_extractor_button.pressed.connect(_on_place_extractor)
 	build_hub_button.pressed.connect(_on_place_transport_hub)
+	build_lab_button.pressed.connect(_on_place_ship_lab)
+	craft_shield_button.pressed.connect(_on_craft_shield)
+	lab_close_button.pressed.connect(func(): lab_menu.visible = false)
+	lab_next_button.pressed.connect(_on_lab_next)
+	lab_buy_button.pressed.connect(_on_lab_buy)
+	for i in range(lab_vessel_buttons.size()):
+		lab_vessel_buttons[i].pressed.connect(_on_lab_vessel.bind(i))
 	info_close_button.pressed.connect(_close_info)
 	info_build_button.pressed.connect(_confirm_build)
 
@@ -151,6 +185,7 @@ func _ready() -> void:
 	craft_menu.visible = false
 	formation_menu.visible = false
 	skill_menu.visible = false
+	lab_menu.visible = false
 	action_button.visible = false
 
 
@@ -183,7 +218,7 @@ func _unhandled_input(event: InputEvent) -> void:
 			formation_editor.handle_drag(event)
 		get_viewport().set_input_as_handled()
 		return
-	if build_menu.visible or craft_menu.visible or world_map.visible:
+	if build_menu.visible or craft_menu.visible or world_map.visible or lab_menu.visible:
 		# These panels have no raw-input handler of their own, but the world
 		# behind them must still not react.
 		get_viewport().set_input_as_handled()
@@ -205,7 +240,7 @@ func _process(delta: float) -> void:
 		_refresh_craft_status()
 
 	if world_map.visible or build_menu.visible or craft_menu.visible \
-			or formation_menu.visible or skill_menu.visible:
+			or formation_menu.visible or skill_menu.visible or lab_menu.visible:
 		current_building = null
 		pending_building = null
 		action_button.visible = false
@@ -237,6 +272,8 @@ func _action_icon_for(type: String) -> int:
 			return IconButton.Icon.SHIP
 		GameState.BUILDING_TRANSPORT_HUB:
 			return IconButton.Icon.TRANSPORT_HUB
+		GameState.BUILDING_SHIP_LAB:
+			return IconButton.Icon.SHIP_LAB
 		GameState.BUILDING_MOTHERSHIP:
 			return IconButton.Icon.MOTHERSHIP
 		_:
@@ -262,6 +299,9 @@ func _on_action_pressed() -> void:
 	elif current_building.building_type == GameState.BUILDING_SHIP_CRAFTER:
 		craft_menu.visible = true
 		_refresh_craft_status()
+	elif current_building.building_type == GameState.BUILDING_SHIP_LAB:
+		lab_menu.visible = true
+		_refresh_lab()
 	elif current_building.building_type == GameState.BUILDING_COMMAND_CENTER:
 		formation_menu.visible = true
 		formation_editor.queue_redraw()
@@ -354,6 +394,10 @@ func _on_place_command_center() -> void:
 	_show_building_info(GameState.BUILDING_COMMAND_CENTER)
 
 
+func _on_place_ship_lab() -> void:
+	_show_building_info(GameState.BUILDING_SHIP_LAB)
+
+
 func _on_place_transport_hub() -> void:
 	_show_building_info(GameState.BUILDING_TRANSPORT_HUB)
 
@@ -368,6 +412,8 @@ func cost_of(type: String) -> int:
 	match type:
 		GameState.BUILDING_TRANSPORT_HUB:
 			return GameState.TRANSPORT_HUB_COST
+		GameState.BUILDING_SHIP_LAB:
+			return GameState.SHIP_LAB_COST
 		GameState.BUILDING_MOTHERSHIP:
 			return GameState.MOTHERSHIP_COST
 		GameState.BUILDING_SHIP_CRAFTER:
@@ -547,6 +593,8 @@ func _refresh_craft_status() -> void:
 		and GameState.can_station_transporter()
 	craft_transporter_button.queue_redraw()
 
+	craft_shield_button.enabled = GameState.shield_vessel_unlocked()
+	craft_shield_button.queue_redraw()
 	craft_store_label.text = "Store ore here\nHold %d" % GameState.fleet_cargo
 	# Deliberately left ENABLED with an empty hold: a greyed-out button that
 	# cannot say why is exactly the dead-button problem this panel already
@@ -645,6 +693,118 @@ func _on_craft_transporter() -> void:
 	_refresh_craft_status()
 
 
+# --- ship lab (#5) --------------------------------------------------------
+
+func _lab_options() -> Array:
+	# The shield VESSEL unlock is offered on the shield page as an extra
+	# entry, because unlocking the type and upgrading it belong in the same
+	# place - and its upgrades are pointless until it exists.
+	var options: Array = []
+	if lab_vessel == GameState.VESSEL_SHIELD and not GameState.shield_vessel_unlocked():
+		options.append({"unlock": true, "name": "Unlock Shield Vessel",
+			"desc": "Lets the ship crafter build shield vessels. Its shield absorbs one lethal hit, then cycles back up.",
+			"cost": GameState.UNLOCK_SHIELD_COST})
+	for u in GameState.upgrades_for(lab_vessel):
+		options.append({"unlock": false, "id": u.id, "name": u.name, "desc": u.desc})
+	return options
+
+
+func _on_lab_vessel(index: int) -> void:
+	lab_vessel = [GameState.VESSEL_INTERCEPTOR, GameState.VESSEL_SHIELD,
+		GameState.VESSEL_TRANSPORTER][index]
+	lab_choice = 0
+	_refresh_lab()
+
+
+func _on_lab_next() -> void:
+	var options: Array = _lab_options()
+	if options.is_empty():
+		return
+	lab_choice = (lab_choice + 1) % options.size()
+	_refresh_lab()
+
+
+func _on_lab_buy() -> void:
+	var options: Array = _lab_options()
+	if options.is_empty():
+		return
+	var choice: Dictionary = options[lab_choice]
+	if choice.unlock:
+		if GameState.unlock_shield_vessel():
+			lab_status.text = "Shield vessel unlocked - build one at a ship crafter"
+		else:
+			lab_status.text = "Not enough ore: needs %d, you have %d" % [
+				GameState.UNLOCK_SHIELD_COST, GameState.rocks
+			]
+		lab_choice = 0
+		_refresh_lab()
+		return
+	var id: String = choice.id
+	if GameState.upgrade_maxed(id):
+		lab_status.text = "%s is already fully researched" % choice.name
+		return
+	var cost: int = GameState.upgrade_cost(id)
+	if not GameState.buy_upgrade(id):
+		lab_status.text = "Not enough ore: needs %d, you have %d" % [cost, GameState.rocks]
+		return
+	lab_status.text = "%s is now level %d" % [choice.name, GameState.upgrade_level(id)]
+	_refresh_lab()
+
+
+func _refresh_lab() -> void:
+	for i in range(lab_vessel_buttons.size()):
+		var this_vessel: String = [GameState.VESSEL_INTERCEPTOR, GameState.VESSEL_SHIELD,
+			GameState.VESSEL_TRANSPORTER][i]
+		lab_vessel_buttons[i].enabled = this_vessel != lab_vessel
+		lab_vessel_buttons[i].queue_redraw()
+	lab_vessel_label.text = GameState.VESSEL_NAMES.get(lab_vessel, lab_vessel)
+
+	var options: Array = _lab_options()
+	if options.is_empty():
+		lab_list.text = ""
+		lab_detail.text = ""
+		lab_buy_button.enabled = false
+		return
+	lab_choice = clampi(lab_choice, 0, options.size() - 1)
+
+	# The whole page at a glance, with the selected line marked - so the
+	# player can see what else is there without stepping through it.
+	var lines: Array = []
+	for i in range(options.size()):
+		var o: Dictionary = options[i]
+		var marker: String = ">" if i == lab_choice else " "
+		if o.unlock:
+			lines.append("%s %s   %d ore" % [marker, o.name, GameState.UNLOCK_SHIELD_COST])
+		else:
+			var lvl: int = GameState.upgrade_level(o.id)
+			var max_lvl: int = int(GameState.upgrade_def(o.id).max_level)
+			var price: String = "MAX" if GameState.upgrade_maxed(o.id) else "%d ore" % GameState.upgrade_cost(o.id)
+			lines.append("%s %s   %d/%d   %s" % [marker, o.name, lvl, max_lvl, price])
+	lab_list.text = "\n".join(lines)
+
+	var choice: Dictionary = options[lab_choice]
+	lab_detail.text = "%s\n%s" % [choice.name, choice.desc]
+	if choice.unlock:
+		lab_buy_button.enabled = GameState.can_afford(GameState.UNLOCK_SHIELD_COST)
+	else:
+		lab_buy_button.enabled = GameState.can_buy_upgrade(choice.id)
+	lab_buy_button.queue_redraw()
+
+
+func _on_craft_shield() -> void:
+	if craft_building_id == 0:
+		return
+	if not GameState.shield_vessel_unlocked():
+		_say("Shield vessels must be unlocked at a ship lab first")
+		return
+	if fleet.ships.size() + GameState.vessels_owed.size() \
+			+ GameState.pending_orders(craft_building_id) >= GameState.max_fleet_size():
+		_say("Fleet is full (%d slots)" % GameState.max_fleet_size())
+		return
+	GameState.queue_order(craft_building_id, GameState.VESSEL_SHIELD)
+	_report_order(GameState.VESSEL_SHIELD)
+
+
 func _on_formation_changed() -> void:
 	fleet.apply_formation()
 

Building.gd

@@ -29,6 +29,16 @@ const MOTHERSHIP_COLOR: Color = Color(0.45, 0.9, 0.55)
 const CRAFTER_COLOR: Color = Color(1.0, 0.72, 0.25)
 const COMMAND_COLOR: Color = Color(0.55, 0.6, 1.0)
 const TRANSPORT_HUB_COLOR: Color = Color(0.95, 0.55, 0.85)
+const SHIP_LAB_COLOR: Color = Color(0.55, 0.95, 0.9)
+
+# Ship lab: a test frame with a vessel held in it and instruments sweeping
+# over it. Reads as a workshop rather than a factory - the crafter already
+# owns "assembly line", so this is measurement, not production.
+const LAB_FRAME_W: float = 78.0
+const LAB_FRAME_H: float = 58.0
+const LAB_MOUNT_RADIUS: float = 15.0
+const LAB_SCANNER_ORBIT: float = 96.0
+const LAB_SCAN_SPEED: float = 0.9
 
 # Transport hub: an octagonal dock ring with berths around it and a freight
 # core in the middle. Deliberately radial-but-flat, so it does not read as a
@@ -100,6 +110,8 @@ var _hull_holder: Node2D = null
 var _hull_pieces: Array = []
 # Rotating holder for the transports stationed at a transport hub (#18).
 var _hub_traffic: Node2D = null
+# Sweeping instrument booms at a ship lab (#5).
+var _lab_scanners: Node2D = null
 var _flash_ring: NeonPiece = null
 var _wash: NeonPiece = null
 
@@ -120,6 +132,8 @@ func _ready() -> void:
 		_build_mothership_pieces()
 	elif building_type == GameState.BUILDING_TRANSPORT_HUB:
 		_build_hub_pieces()
+	elif building_type == GameState.BUILDING_SHIP_LAB:
+		_build_lab_pieces()
 	queue_redraw()
 
 
@@ -140,6 +154,8 @@ func apply_animation() -> void:
 			_animate_crafter()
 		GameState.BUILDING_TRANSPORT_HUB:
 			_animate_transport_hub()
+		GameState.BUILDING_SHIP_LAB:
+			_animate_ship_lab()
 
 
 # Where the satellites are, and how open the reactor core is. Both are read
@@ -182,6 +198,8 @@ func _draw() -> void:
 			_draw_mothership_static(self)
 		GameState.BUILDING_TRANSPORT_HUB:
 			_draw_transport_hub_static(self)
+		GameState.BUILDING_SHIP_LAB:
+			_draw_ship_lab_static(self)
 		_:
 			_draw_crafter_static(self)
 
@@ -224,6 +242,57 @@ const CMD_TOKEN_RADIUS: float = 9.0
 const CMD_STUD_RADIUS: float = 7.0
 
 
+# --- ship lab -------------------------------------------------------------
+
+func _draw_ship_lab_static(target: CanvasItem) -> void:
+	var c: Color = SHIP_LAB_COLOR
+
+	# Outer test frame, open at the corners so it reads as a rig rather than
+	# a solid hull.
+	for sx in [-1.0, 1.0]:
+		for sy in [-1.0, 1.0]:
+			var corner: Vector2 = Vector2(sx * LAB_FRAME_W, sy * LAB_FRAME_H)
+			NeonDraw.draw_glowing_line(target, corner,
+				corner - Vector2(sx * LAB_FRAME_W * 0.45, 0.0), c, 0.9, 0.42)
+			NeonDraw.draw_glowing_line(target, corner,
+				corner - Vector2(0.0, sy * LAB_FRAME_H * 0.5), c, 0.9, 0.42)
+
+	# The vessel under test, held nose-up in the middle - deliberately the
+	# fleet's own silhouette, so it is obvious what the lab is for.
+	NeonDraw.draw_glowing_polygon(target, PackedVector2Array([
+		Vector2(0, -26), Vector2(13, 12), Vector2(0, 5), Vector2(-13, 12),
+	]), HULL_COLOR, 0.95)
+
+	# Mount ring and its bracing.
+	NeonDraw.draw_glowing_polygon(target, _ring(Vector2.ZERO, LAB_MOUNT_RADIUS, 6, PI / 6.0), c, 0.5,
+		NeonDraw.DEFAULT_CORE, 0.7)
+	for i in range(4):
+		var a: float = (float(i) / 4.0) * TAU + PI / 4.0
+		var dir: Vector2 = Vector2(cos(a), sin(a))
+		NeonDraw.draw_glowing_line(target, dir * LAB_MOUNT_RADIUS, dir * 40.0, c, 0.45, 0.3)
+
+
+func _build_lab_pieces() -> void:
+	# Two instrument booms sweeping round the vessel. One holder, rasterised
+	# once, rotated per frame (#10).
+	_lab_scanners = Node2D.new()
+	add_child(_lab_scanners)
+	for i in range(2):
+		var a: float = float(i) * PI
+		var at: Vector2 = Vector2(cos(a), sin(a)) * LAB_SCANNER_ORBIT
+		var piece: NeonPiece = NeonPiece.create(_lab_scanners, at, SHIP_LAB_COLOR)
+		piece.add_polygon(PackedVector2Array([
+			Vector2(-4, -12), Vector2(4, -12), Vector2(4, 12), Vector2(-4, 12),
+		]))
+		piece.add_line(Vector2(0, 0), Vector2(-cos(a), -sin(a)) * 26.0, 0.3, 0.5)
+		piece.rotation = a
+		piece.queue_redraw()
+
+
+func _animate_ship_lab() -> void:
+	_lab_scanners.rotation = phase_time * LAB_SCAN_SPEED
+
+
 # --- transport hub --------------------------------------------------------
 
 func _draw_transport_hub_static(target: CanvasItem) -> void:

IconButton.gd

@@ -15,7 +15,7 @@ enum Icon {
 	# build menu used to pick from the generic set, which left the mothership
 	# and the command centre sharing a folded-map glyph and neither of them
 	# looking anything like the structure they build.
-	MOTHERSHIP, CRAFTER, COMMAND_CENTER, EXTRACTOR, TRANSPORT_HUB,
+	MOTHERSHIP, CRAFTER, COMMAND_CENTER, EXTRACTOR, TRANSPORT_HUB, SHIP_LAB,
 }
 
 # Size the glyphs were originally drawn against. Every glyph dimension is
@@ -139,6 +139,8 @@ func _draw() -> void:
 			_draw_extractor_icon(center, pulse, s)
 		Icon.TRANSPORT_HUB:
 			_draw_transport_hub_icon(center, pulse, s)
+		Icon.SHIP_LAB:
+			_draw_ship_lab_icon(center, pulse, s)
 
 
 func _draw_close(center: Vector2, pulse: float, s: float) -> void:
@@ -224,6 +226,22 @@ func _draw_mothership_icon(center: Vector2, pulse: float, s: float) -> void:
 		NeonDraw.draw_glowing_polygon(self, ring, _active_color(), pulse, core_color)
 
 
+func _draw_ship_lab_icon(center: Vector2, pulse: float, s: float) -> void:
+	# A vessel inside brackets: something being examined, not built.
+	NeonDraw.draw_glowing_polygon(self, PackedVector2Array([
+		center + Vector2(0, -9) * s, center + Vector2(5, 5) * s,
+		center + Vector2(0, 2) * s, center + Vector2(-5, 5) * s,
+	]), _active_color(), pulse, core_color)
+	for sx in [-1.0, 1.0]:
+		var x: float = sx * 11.0 * s
+		NeonDraw.draw_glowing_line(self, center + Vector2(x, -11 * s), center + Vector2(x, 11 * s),
+			_active_color(), pulse, 0.35 * s, core_color)
+		NeonDraw.draw_glowing_line(self, center + Vector2(x, -11 * s), center + Vector2(x - sx * 4.0 * s, -11 * s),
+			_active_color(), pulse, 0.35 * s, core_color)
+		NeonDraw.draw_glowing_line(self, center + Vector2(x, 11 * s), center + Vector2(x - sx * 4.0 * s, 11 * s),
+			_active_color(), pulse, 0.35 * s, core_color)
+
+
 func _draw_transport_hub_icon(center: Vector2, pulse: float, s: float) -> void:
 	# A ring of docking cradles with a freight box in the middle: reads as
 	# "things are stationed here and go out from here", which is what the hub

Main.tscn

@@ -479,6 +479,48 @@ script = ExtResource("19")
 amount = 30
 digit_height = 40.0
 
+[node name="ShipLabButton" type="Control" parent="UI/BuildMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = 76
+offset_right = 204
+offset_top = 280
+offset_bottom = 408
+script = ExtResource("10")
+icon = 13
+glow_color = Color(0.55, 0.95, 0.9, 1)
+
+[node name="ShipLabLabel" type="Label" parent="UI/BuildMenu"]
+mouse_filter = 2
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = -10
+offset_right = 290
+offset_top = 414
+offset_bottom = 480
+theme_override_font_sizes/font_size = 32
+autowrap_mode = 2
+text = "Ship Lab"
+horizontal_alignment = 1
+
+[node name="ShipLabCost" type="Control" parent="UI/BuildMenu"]
+mouse_filter = 2
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = 80
+offset_right = 200
+offset_top = 484
+offset_bottom = 536
+script = ExtResource("19")
+amount = 35
+digit_height = 40.0
+
 [node name="CloseButton" type="Control" parent="UI/BuildMenu"]
 anchor_left = 1.0
 anchor_right = 1.0
@@ -576,6 +618,162 @@ script = ExtResource("10")
 icon = 1
 glow_color = Color(0, 0.62, 0.7, 1)
 
+[node name="LabMenu" type="Control" parent="UI" groups=["modal_menus"]]
+visible = false
+mouse_filter = 2
+anchor_right = 1.0
+anchor_bottom = 1.0
+
+[node name="Backdrop" type="ColorRect" parent="UI/LabMenu"]
+anchor_right = 1.0
+anchor_bottom = 1.0
+color = Color(0.03, 0.03, 0.08, 0.94)
+
+[node name="TitleLabel" type="Label" parent="UI/LabMenu"]
+mouse_filter = 2
+anchor_right = 1.0
+offset_left = 24
+offset_top = 60
+offset_right = -24
+offset_bottom = 170
+text = "Ship Lab"
+horizontal_alignment = 1
+
+[node name="VesselA" type="Control" parent="UI/LabMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+offset_left = -290
+offset_right = -170
+offset_top = 190
+offset_bottom = 310
+script = ExtResource("10")
+icon = 2
+glow_color = Color(0.25, 0.85, 1, 1)
+
+[node name="VesselB" type="Control" parent="UI/LabMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+offset_left = -60
+offset_right = 60
+offset_top = 190
+offset_bottom = 310
+script = ExtResource("10")
+icon = 2
+glow_color = Color(0.45, 0.8, 1, 1)
+
+[node name="VesselC" type="Control" parent="UI/LabMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+offset_left = 170
+offset_right = 290
+offset_top = 190
+offset_bottom = 310
+script = ExtResource("10")
+icon = 12
+glow_color = Color(0.95, 0.55, 0.85, 1)
+
+[node name="VesselLabel" type="Label" parent="UI/LabMenu"]
+mouse_filter = 2
+anchor_right = 1.0
+offset_left = 24
+offset_top = 318
+offset_right = -24
+offset_bottom = 380
+theme_override_font_sizes/font_size = 34
+horizontal_alignment = 1
+text = ""
+
+[node name="UpgradeList" type="Label" parent="UI/LabMenu"]
+mouse_filter = 2
+anchor_right = 1.0
+anchor_bottom = 1.0
+offset_left = 32
+offset_top = 396
+offset_right = -32
+offset_bottom = -470
+theme_override_font_sizes/font_size = 30
+autowrap_mode = 2
+text = ""
+
+[node name="DetailLabel" type="Label" parent="UI/LabMenu"]
+mouse_filter = 2
+anchor_right = 1.0
+anchor_top = 1.0
+anchor_bottom = 1.0
+offset_left = 32
+offset_top = -460
+offset_right = -32
+offset_bottom = -330
+theme_override_font_sizes/font_size = 32
+autowrap_mode = 2
+horizontal_alignment = 1
+text = ""
+
+[node name="StatusLabel" type="Label" parent="UI/LabMenu"]
+mouse_filter = 2
+anchor_right = 1.0
+anchor_top = 1.0
+anchor_bottom = 1.0
+offset_left = 32
+offset_top = -324
+offset_right = -32
+offset_bottom = -256
+theme_override_font_sizes/font_size = 30
+autowrap_mode = 2
+horizontal_alignment = 1
+text = ""
+
+[node name="NextButton" type="Control" parent="UI/LabMenu"]
+anchor_left = 0.5
+anchor_top = 1.0
+anchor_right = 0.5
+anchor_bottom = 1.0
+offset_left = -230
+offset_right = -110
+offset_top = -240
+offset_bottom = -120
+script = ExtResource("10")
+icon = 6
+glow_color = Color(0.55, 0.95, 0.9, 1)
+
+[node name="BuyButton" type="Control" parent="UI/LabMenu"]
+anchor_left = 0.5
+anchor_top = 1.0
+anchor_right = 0.5
+anchor_bottom = 1.0
+offset_left = 110
+offset_right = 230
+offset_top = -240
+offset_bottom = -120
+script = ExtResource("10")
+icon = 4
+glow_color = Color(0.45, 0.9, 0.55, 1)
+
+[node name="HintLabel" type="Label" parent="UI/LabMenu"]
+mouse_filter = 2
+anchor_right = 1.0
+anchor_top = 1.0
+anchor_bottom = 1.0
+offset_left = 24
+offset_top = -110
+offset_right = -24
+offset_bottom = -20
+theme_override_font_sizes/font_size = 28
+autowrap_mode = 2
+horizontal_alignment = 1
+text = "Next upgrade                    Buy"
+
+[node name="CloseButton" type="Control" parent="UI/LabMenu"]
+anchor_left = 1.0
+anchor_right = 1.0
+offset_left = -172
+offset_top = 24
+offset_right = -24
+offset_bottom = 172
+script = ExtResource("10")
+icon = 1
+glow_color = Color(0.55, 0.95, 0.9, 1)
+
 [node name="CraftMenu" type="Control" parent="UI" groups=["modal_menus"]]
 visible = false
 anchor_right = 1.0
@@ -662,6 +860,34 @@ autowrap_mode = 2
 text = "Transporter"
 horizontal_alignment = 1
 
+[node name="ShieldButton" type="Control" parent="UI/CraftMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = -74
+offset_right = 74
+offset_top = -260
+offset_bottom = -112
+script = ExtResource("10")
+icon = 2
+glow_color = Color(0.45, 0.8, 1, 1)
+
+[node name="ShieldLabel" type="Label" parent="UI/CraftMenu"]
+mouse_filter = 2
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = -160
+offset_right = 160
+offset_top = -104
+offset_bottom = -44
+theme_override_font_sizes/font_size = 32
+autowrap_mode = 2
+text = "Shield Vessel"
+horizontal_alignment = 1
+
 [node name="StoreOreButton" type="Control" parent="UI/CraftMenu"]
 anchor_left = 0.5
 anchor_top = 1.0

WorldMapContent.gd

@@ -11,6 +11,7 @@ const MOTHERSHIP_MARKER_COLOR: Color = Color(0.45, 0.9, 0.55)
 const CRAFTER_MARKER_COLOR: Color = Color(1.0, 0.72, 0.25)
 const COMMAND_MARKER_COLOR: Color = Color(0.55, 0.6, 1.0)
 const TRANSPORT_HUB_MARKER_COLOR: Color = Color(0.95, 0.55, 0.85)
+const SHIP_LAB_MARKER_COLOR: Color = Color(0.55, 0.95, 0.9)
 
 # A structure built on a planet's surface (see GameState.extractors) is not
 # itself a map marker - it is a small badge on the existing planet marker,
@@ -53,6 +54,8 @@ func _building_marker_color(type: String) -> Color:
 			return CRAFTER_MARKER_COLOR
 		GameState.BUILDING_TRANSPORT_HUB:
 			return TRANSPORT_HUB_MARKER_COLOR
+		GameState.BUILDING_SHIP_LAB:
+			return SHIP_LAB_MARKER_COLOR
 		_:
 			return COMMAND_MARKER_COLOR
 
@@ -120,6 +123,8 @@ func _draw() -> void:
 				_draw_marker_polygon(_regular_polygon(marker.position, 7.0, 4, 0.0), marker.color)
 			GameState.BUILDING_TRANSPORT_HUB:
 				_draw_marker_polygon(_regular_polygon(marker.position, 7.5, 8, PI / 8.0), marker.color)
+			GameState.BUILDING_SHIP_LAB:
+				_draw_marker_polygon(_regular_polygon(marker.position, 7.5, 3, -PI / 2.0), marker.color)
 			_:
 				_draw_marker_polygon(_regular_polygon(marker.position, 6.0, 4, PI / 4.0), marker.color)
 

tests/_ingame_buildings_preview.gd

@@ -16,6 +16,7 @@ func _ready() -> void:
 	GameState.add_building(GameState.BUILDING_MOTHERSHIP, Vector2(-330.0, 0.0))
 	GameState.add_building(GameState.BUILDING_SHIP_CRAFTER, Vector2(140.0, 0.0))
 	GameState.add_building(GameState.BUILDING_TRANSPORT_HUB, Vector2(480.0, 0.0))
+	GameState.add_building(GameState.BUILDING_SHIP_LAB, Vector2(820.0, 0.0))
 
 	var main: Node = load("res://Main.tscn").instantiate()
 	add_child(main)
@@ -23,6 +24,6 @@ func _ready() -> void:
 	main.get_node("EnemySpawner").set_process(false)
 	# Park the fleet below the pair so the camera frames both, and zoom out
 	# far enough to see them whole.
-	main.get_node("Fleet").move_to(Vector2(0.0, 210.0))
+	main.get_node("Fleet").move_to(Vector2(240.0, 260.0))
 	var cam: Camera2D = main.get_node("Camera2D")
-	cam.zoom = Vector2(1.0, 1.0)
+	cam.zoom = Vector2(0.78, 0.78)

tests/_lab_menu_preview.gd

@@ -0,0 +1,25 @@
+extends Node2D
+
+# Preview, not a test. The ship lab's upgrade screen (#5), so its layout can
+# be checked on a real viewport - headless draws no pixels.
+#
+#   bash tests/screenshot.sh res://tests/_lab_menu_preview.tscn /tmp/lab.png 20 720x1280
+
+
+func _ready() -> void:
+	GameState.buildings.clear()
+	GameState.extractors.clear()
+	GameState.transporters.clear()
+	GameState.reset_progression()
+	GameState.rocks = 240
+	GameState.unlocked = ["shipyards", "vessel_science"]
+	var main: Node = load("res://Main.tscn").instantiate()
+	add_child(main)
+	main.get_node("BuildingField").place(GameState.BUILDING_SHIP_LAB, Vector2(400.0, 0.0))
+	# A level already bought, so the list shows both a researched and an
+	# unresearched line rather than a uniform page of zeroes.
+	GameState.vessel_levels["int_damage"] = 1
+	var bc: Node = main.get_node("BuildController")
+	main.get_node("UI/LabMenu").visible = true
+	bc.lab_vessel = GameState.VESSEL_INTERCEPTOR
+	bc._refresh_lab()

tests/_lab_menu_preview.gd.uid

@@ -0,0 +1 @@
+uid://dlueabpa84uyf

tests/_lab_menu_preview.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://tests/_lab_menu_preview.gd" id="1"]
+
+[node name="LabMenuPreview" type="Node2D"]
+script = ExtResource("1")

tests/test_shield_vessel.gd

@@ -0,0 +1,181 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_shield_vessel.gd
+# Forgejo #5: the shield vessel's shield absorbs a hit that would destroy any
+# other ship, and is then down until it cycles back up.
+#
+# The shield is PERSONAL - it protects the vessel carrying it and nothing
+# else. Ships have no health in this game: contact with an enemy or an
+# asteroid destroys them outright, so "absorbs a hit" means surviving the
+# collision that would otherwise have killed it.
+#
+# Verifies:
+#   1. an ordinary interceptor still dies to a rock (so the shield result
+#      below means something)
+#   2. a shield vessel survives the same rock, and the rock is destroyed
+#   3. its shield is then DOWN - a second rock while it is cycling kills it,
+#      or the shield would be permanent invulnerability
+#   4. the shield comes back on its own after the recharge time
+#   5. researched capacity lets it take more than one hit
+#   6. the recharge upgrade actually shortens the wait
+
+var game_state: Node
+var scene: Node
+var fleet: Node
+var interceptor: Node
+var shield_ship: Node
+var stage: int = 0
+var elapsed: float = 0.0
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+	game_state.buildings.clear()
+	game_state.extractors.clear()
+	game_state.transporters.clear()
+	game_state.vessels_owed.clear()
+	game_state.reset_progression()
+	game_state.rocks = 2000
+	scene = load("res://Main.tscn").instantiate()
+	root.add_child(scene)
+	fleet = scene.get_node("Fleet")
+
+
+func _rock_onto(ship: Node) -> void:
+	var rock: Area2D = load("res://Asteroid.tscn").instantiate()
+	rock.velocity = Vector2.ZERO
+	rock.global_position = ship.global_position
+	scene.add_child(rock)
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			scene.get_node("AsteroidField").set_process(false)
+			scene.get_node("EnemySpawner").set_process(false)
+			for a in get_nodes_in_group("asteroids"):
+				if is_instance_valid(a):
+					a.queue_free()
+			fleet.spawn_ships(1, Vector2.ZERO)
+			interceptor = fleet.ships[0]
+			# Well clear of the interceptor, or one rock hits both.
+			fleet.add_ship(GameState.VESSEL_SHIELD)
+			shield_ship = fleet.ships[1]
+			shield_ship.position = Vector2(2000.0, 0.0)
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			if elapsed < 0.2:
+				return false
+			if not shield_ship.has_shield():
+				print("TEST_SHIELD_VESSEL: FAIL (a fresh shield vessel has no shield)")
+				quit(1)
+				return true
+			# --- 1. the control: an interceptor dies --------------------
+			_rock_onto(interceptor)
+			elapsed = 0.0
+			stage = 2
+			return false
+		2:
+			if elapsed < 0.4:
+				return false
+			if is_instance_valid(interceptor):
+				print("TEST_SHIELD_VESSEL: FAIL (an ordinary interceptor survived a rock - the test proves nothing)")
+				quit(1)
+				return true
+			print("control: interceptor destroyed by a rock")
+
+			# --- 2. the shield vessel survives it -----------------------
+			_rock_onto(shield_ship)
+			elapsed = 0.0
+			stage = 3
+			return false
+		3:
+			if elapsed < 0.4:
+				return false
+			if not is_instance_valid(shield_ship):
+				print("TEST_SHIELD_VESSEL: FAIL (the shield did not absorb the hit)")
+				quit(1)
+				return true
+			if shield_ship.has_shield():
+				print("TEST_SHIELD_VESSEL: FAIL (shield still up after taking a hit - it never goes down)")
+				quit(1)
+				return true
+			print("shield vessel survived, shield now down")
+
+			# --- 3. defenceless while it cycles -------------------------
+			_rock_onto(shield_ship)
+			elapsed = 0.0
+			stage = 4
+			return false
+		4:
+			if elapsed < 0.4:
+				return false
+			if is_instance_valid(shield_ship):
+				print("TEST_SHIELD_VESSEL: FAIL (survived a second hit with the shield down - it is just invulnerable)")
+				quit(1)
+				return true
+			print("second hit while cycling destroyed it, as it should")
+
+			# --- 4 + 5. recharge, and researched capacity ---------------
+			game_state.vessel_levels["shd_hits"] = 1
+			fleet.add_ship(GameState.VESSEL_SHIELD)
+			shield_ship = fleet.ships[fleet.ships.size() - 1]
+			shield_ship.position = Vector2(-2000.0, 0.0)
+			elapsed = 0.0
+			stage = 5
+			return false
+		5:
+			if elapsed < 0.2:
+				return false
+			if shield_ship.shield_charges != game_state.shield_max_charges():
+				print("TEST_SHIELD_VESSEL: FAIL (researched capacity %d, vessel has %d)" % [
+					game_state.shield_max_charges(), shield_ship.shield_charges
+				])
+				quit(1)
+				return true
+			print("with Layered Emitters researched: %d charges" % shield_ship.shield_charges)
+			_rock_onto(shield_ship)
+			elapsed = 0.0
+			stage = 6
+			return false
+		6:
+			if elapsed < 0.4:
+				return false
+			if not is_instance_valid(shield_ship) or not shield_ship.has_shield():
+				print("TEST_SHIELD_VESSEL: FAIL (a two-charge shield did not survive one hit with a charge left)")
+				quit(1)
+				return true
+			print("two-charge shield took a hit and is still up (%d left)" % shield_ship.shield_charges)
+
+			# --- 6. the recharge upgrade shortens the wait --------------
+			var slow: float = game_state.shield_recharge_time()
+			game_state.vessel_levels["shd_recharge"] = 2
+			var fast: float = game_state.shield_recharge_time()
+			print("recharge %.1fs -> %.1fs with Fast Cycling" % [slow, fast])
+			if fast >= slow:
+				print("TEST_SHIELD_VESSEL: FAIL (the recharge upgrade did not shorten the wait)")
+				quit(1)
+				return true
+
+			# --- 4. it really does come back ----------------------------
+			shield_ship.shield_charges = 0
+			shield_ship.shield_recharge_left = 0.15
+			elapsed = 0.0
+			stage = 7
+			return false
+		7:
+			if elapsed < 0.6:
+				return false
+			if not shield_ship.has_shield():
+				print("TEST_SHIELD_VESSEL: FAIL (the shield never cycled back up)")
+				quit(1)
+				return true
+			print("shield cycled back up on its own")
+			print("TEST_SHIELD_VESSEL: PASS")
+			quit(0)
+			return true
+	return false

tests/test_shield_vessel.gd.uid

@@ -0,0 +1 @@
+uid://bmhp0nqvetr56

tests/test_ship_lab.gd

@@ -0,0 +1,177 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_ship_lab.gd
+# Forgejo #5: the ship lab researches upgrades per vessel type and unlocks
+# new vessel types. The shield vessel is the first of those.
+#
+# Verifies:
+#   1. the lab is gated behind its own research node, like every structure
+#   2. upgrades cannot be bought without a lab built - it is a place you go,
+#      not a menu that exists once researched
+#   3. buying raises the level, charges the escalating price, and stops at
+#      max
+#   4. an upgrade improves the ships ALREADY FLYING, not just the next one
+#      built
+#   5. the shield vessel is unlocked at the lab, and only then can the
+#      crafter build one
+#   6. a shield vessel is what comes back from production - a typed order
+#      must not decay into an interceptor
+#   7. upgrades are per vessel type: an interceptor upgrade does not tune
+#      the transporter
+
+var game_state: Node
+var scene: Node
+var fleet: Node
+var field: Node
+var controller: Node
+var crafter_id: int = 0
+var stage: int = 0
+var elapsed: float = 0.0
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+	game_state.buildings.clear()
+	game_state.extractors.clear()
+	game_state.transporters.clear()
+	game_state.vessels_owed.clear()
+	game_state.reset_progression()
+	game_state.rocks = 1200
+	game_state.fleet_cargo = 0
+	scene = load("res://Main.tscn").instantiate()
+	root.add_child(scene)
+	fleet = scene.get_node("Fleet")
+	field = scene.get_node("BuildingField")
+	controller = scene.get_node("BuildController")
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			scene.get_node("AsteroidField").set_process(false)
+			scene.get_node("EnemySpawner").set_process(false)
+			for a in get_nodes_in_group("asteroids"):
+				if is_instance_valid(a):
+					a.queue_free()
+
+			# --- 1. gated behind research -------------------------------
+			if game_state.is_building_unlocked(GameState.BUILDING_SHIP_LAB):
+				print("TEST_SHIP_LAB: FAIL (lab buildable with no research)")
+				quit(1)
+				return true
+			var gate: String = game_state.research_for_building(GameState.BUILDING_SHIP_LAB)
+			if gate == "":
+				print("TEST_SHIP_LAB: FAIL (no research node gates the lab)")
+				quit(1)
+				return true
+			print("lab gated behind '%s'" % gate)
+
+			# --- 2. no lab, no upgrades ---------------------------------
+			if game_state.can_buy_upgrade("int_damage"):
+				print("TEST_SHIP_LAB: FAIL (upgrades purchasable with no lab built)")
+				quit(1)
+				return true
+			if game_state.buy_upgrade("int_damage"):
+				print("TEST_SHIP_LAB: FAIL (bought an upgrade with no lab built)")
+				quit(1)
+				return true
+			print("no lab -> no upgrades")
+
+			game_state.unlocked = ["shipyards", "vessel_science", "coordination", "wing", "squadron"]
+			field.place(GameState.BUILDING_SHIP_LAB, Vector2(-700.0, 0.0))
+			field.place(GameState.BUILDING_SHIP_CRAFTER, Vector2(700.0, 0.0))
+			crafter_id = int(game_state.buildings[-1].id)
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			if elapsed < 0.3:
+				return false
+			# --- 3. buying raises the level and charges ------------------
+			var before_rocks: int = game_state.rocks
+			var first_cost: int = game_state.upgrade_cost("int_damage")
+			if not game_state.buy_upgrade("int_damage"):
+				print("TEST_SHIP_LAB: FAIL (could not buy an upgrade with a lab built)")
+				quit(1)
+				return true
+			if game_state.upgrade_level("int_damage") != 1:
+				print("TEST_SHIP_LAB: FAIL (level did not rise)")
+				quit(1)
+				return true
+			if game_state.rocks != before_rocks - first_cost:
+				print("TEST_SHIP_LAB: FAIL (wrong price charged)")
+				quit(1)
+				return true
+			var second_cost: int = game_state.upgrade_cost("int_damage")
+			if second_cost <= first_cost:
+				print("TEST_SHIP_LAB: FAIL (level 2 costs %d, no more than level 1 at %d)" % [second_cost, first_cost])
+				quit(1)
+				return true
+			print("bought level 1 for %d, level 2 now costs %d" % [first_cost, second_cost])
+
+			# --- 4. it reaches ships already flying ----------------------
+			var flying: Node = fleet.ships[0]
+			if flying.projectile_damage != GameState.SHIP_BASE_DAMAGE + 1:
+				print("TEST_SHIP_LAB: FAIL (a ship already flying still does %d damage)" % flying.projectile_damage)
+				quit(1)
+				return true
+			print("ship already flying now does %d damage" % flying.projectile_damage)
+
+			# --- 7. per vessel type --------------------------------------
+			var trn_speed_before: float = game_state.transporter_speed()
+			game_state.buy_upgrade("int_speed")
+			if game_state.transporter_speed() != trn_speed_before:
+				print("TEST_SHIP_LAB: FAIL (an interceptor upgrade changed the transporter)")
+				quit(1)
+				return true
+			print("interceptor upgrades leave the transporter alone")
+
+			# --- 5. the shield vessel is unlocked at the lab -------------
+			if game_state.shield_vessel_unlocked():
+				print("TEST_SHIP_LAB: FAIL (shield vessel available before it was unlocked)")
+				quit(1)
+				return true
+			if game_state.queue_order(crafter_id, GameState.VESSEL_SHIELD):
+				print("TEST_SHIP_LAB: FAIL (crafter took a shield order before the type was unlocked)")
+				quit(1)
+				return true
+			if not game_state.unlock_shield_vessel():
+				print("TEST_SHIP_LAB: FAIL (could not unlock the shield vessel at the lab)")
+				quit(1)
+				return true
+			print("shield vessel unlocked at the lab")
+
+			# --- 6. a typed order comes back as that type ----------------
+			fleet.spawn_ships(1, Vector2.ZERO)
+			if not game_state.queue_order(crafter_id, GameState.VESSEL_SHIELD):
+				print("TEST_SHIP_LAB: FAIL (crafter refused a shield order after unlocking)")
+				quit(1)
+				return true
+			game_state.deposit_to_building(crafter_id, GameState.SHIELD_COST)
+			elapsed = 0.0
+			stage = 2
+			return false
+		2:
+			if elapsed < 0.6:
+				return false
+			var shield_ship: Node = null
+			for ship in fleet.ships:
+				if is_instance_valid(ship) and ship.vessel_type == GameState.VESSEL_SHIELD:
+					shield_ship = ship
+			if shield_ship == null:
+				print("TEST_SHIP_LAB: FAIL (the shield order produced no shield vessel: %d ships, owed %s)" % [
+					fleet.ships.size(), game_state.vessels_owed
+				])
+				quit(1)
+				return true
+			if not shield_ship.has_shield():
+				print("TEST_SHIP_LAB: FAIL (the shield vessel arrived with no shield up)")
+				quit(1)
+				return true
+			print("shield vessel built, shield up with %d charge(s)" % shield_ship.shield_charges)
+			print("TEST_SHIP_LAB: PASS")
+			quit(0)
+			return true
+	return false

tests/test_ship_lab.gd.uid

@@ -0,0 +1 @@
+uid://cwwl0p787wqdh