Transport Hub building

Forgejo #18, part 5 of #12. The building only - the vessels that do the
hauling are #19. Placeable, costed at 30, gated behind a new "Freight
Handling" research node hanging off Logistics, with its own info popup,
build-menu glyph and map marker.

Drawn as an octagonal dock ring with berth arms and a squared-off freight
core: deliberately radial-but-flat so it does not read as a small
mothership, which is the only structure with swept arms. Its stationed
transports are NeonPiece children of one rotating holder, per #10 - the
geometry is rasterised once and only the holder's rotation changes, so
the traffic costs no redraws.

Building._draw()'s match has a catch-all that renders anything
unrecognised as a ship crafter, so a missing case is silent and looks
almost right. The test checks for the hub's own _hub_traffic holder
rather than trusting that something plausible appeared - which caught
exactly that: a _ready() patch had silently not applied and the hub was
rendering through the crafter branch.

The build menu grew a third row. Every button, label and price moved:
the old row occupied 332px against a 372px pitch, and three of those do
not fit above a 1280px screen. Rows are now shorter (128px buttons, 40px
price digits) at a 290px pitch, ending at y=1176. Rendered and looked at
- the first attempt tightened the pitch alone and left every price
overlapping the row beneath it, which no headless test would have seen.

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

BuildController.gd

@@ -27,6 +27,7 @@ extends Node2D
 @onready var build_close_button: IconButton = get_node("../UI/BuildMenu/CloseButton")
 @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 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")
@@ -76,6 +77,10 @@ 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_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.",
+	},
 	GameState.BUILDING_EXTRACTOR: {
 		"title": "Extractor",
 		"body": "Mines a planet and runs a hauler to your mothership. It keeps earning while you are away.",
@@ -100,6 +105,7 @@ func _ready() -> void:
 	build_crafter_button.pressed.connect(_on_place_crafter)
 	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)
 	info_close_button.pressed.connect(_close_info)
 	info_build_button.pressed.connect(_confirm_build)
 
@@ -194,6 +200,8 @@ func _action_icon_for(type: String) -> int:
 	match type:
 		GameState.BUILDING_SHIP_CRAFTER:
 			return IconButton.Icon.SHIP
+		GameState.BUILDING_TRANSPORT_HUB:
+			return IconButton.Icon.TRANSPORT_HUB
 		GameState.BUILDING_MOTHERSHIP:
 			return IconButton.Icon.MOTHERSHIP
 		_:
@@ -243,6 +251,7 @@ func _refresh_build_status() -> void:
 	# explain itself in the info popup.
 	build_crafter_button.enabled = GameState.is_building_unlocked(GameState.BUILDING_SHIP_CRAFTER)
 	build_command_button.enabled = GameState.is_building_unlocked(GameState.BUILDING_COMMAND_CENTER)
+	build_hub_button.enabled = GameState.is_building_unlocked(GameState.BUILDING_TRANSPORT_HUB)
 	build_extractor_button.enabled = _planet_under_fleet() != null \
 		and GameState.is_building_unlocked(GameState.BUILDING_EXTRACTOR)
 
@@ -266,6 +275,10 @@ func _on_place_command_center() -> void:
 	_show_building_info(GameState.BUILDING_COMMAND_CENTER)
 
 
+func _on_place_transport_hub() -> void:
+	_show_building_info(GameState.BUILDING_TRANSPORT_HUB)
+
+
 func _on_place_extractor() -> void:
 	# The option stays pressable while greyed, so this is also how a
 	# not-over-a-planet extractor explains itself.
@@ -274,6 +287,8 @@ func _on_place_extractor() -> void:
 
 func cost_of(type: String) -> int:
 	match type:
+		GameState.BUILDING_TRANSPORT_HUB:
+			return GameState.TRANSPORT_HUB_COST
 		GameState.BUILDING_MOTHERSHIP:
 			return GameState.MOTHERSHIP_COST
 		GameState.BUILDING_SHIP_CRAFTER:

Building.gd

@@ -28,6 +28,19 @@ extends Node2D
 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)
+
+# 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
+# small mothership - the mothership is the only thing with swept arms.
+const HUB_RING_RADIUS: float = 74.0
+const HUB_DECK_RADIUS: float = 54.0
+const HUB_CORE_RADIUS: float = 22.0
+const HUB_BERTH_COUNT: int = 8
+const HUB_BERTH_LENGTH: float = 20.0
+const HUB_DOCKED_COUNT: int = 3
+const HUB_DOCKED_ORBIT: float = 96.0
+const HUB_SPIN_SPEED: float = 0.22
 # The vessel on the assembly line is drawn in the fleet's own colour, so it
 # reads as "one of yours being built" rather than as shipyard machinery.
 const HULL_COLOR: Color = Color(0.25, 0.85, 1.0)
@@ -85,6 +98,8 @@ var _hoist: NeonPiece = null
 var _sparks: Node2D = null
 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
 var _flash_ring: NeonPiece = null
 var _wash: NeonPiece = null
 
@@ -103,6 +118,8 @@ func _ready() -> void:
 		_build_crafter_pieces()
 	elif building_type == GameState.BUILDING_MOTHERSHIP:
 		_build_mothership_pieces()
+	elif building_type == GameState.BUILDING_TRANSPORT_HUB:
+		_build_hub_pieces()
 	queue_redraw()
 
 
@@ -121,6 +138,8 @@ func apply_animation() -> void:
 			_animate_mothership()
 		GameState.BUILDING_SHIP_CRAFTER:
 			_animate_crafter()
+		GameState.BUILDING_TRANSPORT_HUB:
+			_animate_transport_hub()
 
 
 # Where the satellites are, and how open the reactor core is. Both are read
@@ -161,6 +180,8 @@ func _draw() -> void:
 			_draw_command_center()
 		GameState.BUILDING_MOTHERSHIP:
 			_draw_mothership_static(self)
+		GameState.BUILDING_TRANSPORT_HUB:
+			_draw_transport_hub_static(self)
 		_:
 			_draw_crafter_static(self)
 
@@ -203,6 +224,50 @@ const CMD_TOKEN_RADIUS: float = 9.0
 const CMD_STUD_RADIUS: float = 7.0
 
 
+# --- transport hub --------------------------------------------------------
+
+func _draw_transport_hub_static(target: CanvasItem) -> void:
+	var c: Color = TRANSPORT_HUB_COLOR
+
+	# Dock ring and the deck nested inside it.
+	NeonDraw.draw_glowing_polygon(target, _ring(Vector2.ZERO, HUB_RING_RADIUS, HUB_BERTH_COUNT, PI / 8.0), c, 1.0)
+	NeonDraw.draw_glowing_polygon(target, _ring(Vector2.ZERO, HUB_DECK_RADIUS, HUB_BERTH_COUNT, PI / 8.0), c, 0.45, NeonDraw.DEFAULT_CORE, 0.7)
+
+	# Freight core: a squared-off hold rather than a reactor, so it reads as
+	# storage and not as another power plant.
+	NeonDraw.draw_glowing_polygon(target, _ring(Vector2.ZERO, HUB_CORE_RADIUS, 4, PI / 4.0), c, 0.95)
+
+	for i in range(HUB_BERTH_COUNT):
+		var a: float = (float(i) / HUB_BERTH_COUNT) * TAU + PI / 8.0
+		var dir: Vector2 = Vector2(cos(a), sin(a))
+		NeonDraw.draw_glowing_line(target, dir * HUB_CORE_RADIUS, dir * HUB_DECK_RADIUS, c, 0.5, 0.32)
+		# Berth arm standing off the ring, where a transporter parks.
+		NeonDraw.draw_glowing_line(target, dir * HUB_RING_RADIUS,
+			dir * (HUB_RING_RADIUS + HUB_BERTH_LENGTH), c, 0.75, 0.38)
+
+
+func _build_hub_pieces() -> void:
+	# Stationed transports, as NeonPiece children of one holder that turns.
+	# Per #10 the geometry is rasterised once and only the holder's rotation
+	# changes, so the traffic costs no redraws at all.
+	_hub_traffic = Node2D.new()
+	add_child(_hub_traffic)
+	for i in range(HUB_DOCKED_COUNT):
+		var a: float = (float(i) / HUB_DOCKED_COUNT) * TAU
+		var at: Vector2 = Vector2(cos(a), sin(a)) * HUB_DOCKED_ORBIT
+		var piece: NeonPiece = NeonPiece.create(_hub_traffic, at, TRANSPORT_HUB_COLOR)
+		# A stubby freighter: blunt, boxy, nothing like the fleet's darts.
+		piece.add_polygon(PackedVector2Array([
+			Vector2(-9, -5), Vector2(9, -5), Vector2(12, 0), Vector2(9, 5), Vector2(-9, 5),
+		]))
+		piece.rotation = a + PI / 2.0
+		piece.queue_redraw()
+
+
+func _animate_transport_hub() -> void:
+	_hub_traffic.rotation = phase_time * HUB_SPIN_SPEED
+
+
 func _diamond(centre: Vector2, r: float) -> PackedVector2Array:
 	return PackedVector2Array([
 		centre + Vector2(0, -r), centre + Vector2(r, 0),

GameState.gd

@@ -101,9 +101,13 @@ const BUILDING_COMMAND_CENTER: String = "command_center"
 # Extractors are not placed in space like the others - they are built ON a
 # planet's surface and tracked separately (see `extractors`).
 const BUILDING_EXTRACTOR: String = "extractor"
+# Hosts the transport vessels that supply other buildings (#18). Built in
+# space like the rest; it is the transporters (#19) that do the moving.
+const BUILDING_TRANSPORT_HUB: String = "transport_hub"
 
 const COMMAND_CENTER_COST: int = 15
 const EXTRACTOR_COST: int = 25
+const TRANSPORT_HUB_COST: int = 30
 
 var buildings: Array = []
 
@@ -136,6 +140,11 @@ const SKILL_TREE: Array = [
 		"x": 0.82, "unlocks": BUILDING_COMMAND_CENTER,
 		"desc": "Build command centers, where the fleet formation is arranged.",
 	},
+	{
+		"id": "freight", "name": "Freight Handling", "cost": 40, "requires": "logistics",
+		"x": 0.18, "unlocks": BUILDING_TRANSPORT_HUB,
+		"desc": "Build transport hubs, which supply your other buildings with ore.",
+	},
 	{
 		"id": "wing", "name": "Wing Doctrine", "cost": 30, "requires": "coordination",
 		"x": 0.82, "fleet_bonus": 1,

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,
+	MOTHERSHIP, CRAFTER, COMMAND_CENTER, EXTRACTOR, TRANSPORT_HUB,
 }
 
 # Size the glyphs were originally drawn against. Every glyph dimension is
@@ -119,6 +119,8 @@ func _draw() -> void:
 			_draw_command_icon(center, pulse, s)
 		Icon.EXTRACTOR:
 			_draw_extractor_icon(center, pulse, s)
+		Icon.TRANSPORT_HUB:
+			_draw_transport_hub_icon(center, pulse, s)
 
 
 func _draw_close(center: Vector2, pulse: float, s: float) -> void:
@@ -204,6 +206,32 @@ func _draw_mothership_icon(center: Vector2, pulse: float, s: float) -> void:
 		NeonDraw.draw_glowing_polygon(self, ring, _active_color(), pulse, 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
+	# does, and shares no silhouette with the crafter's open cradle.
+	var ring_r: float = 11.0 * s
+	var ring: PackedVector2Array = PackedVector2Array()
+	for i in range(8):
+		var a: float = (float(i) / 8.0) * TAU + PI / 8.0
+		ring.append(center + Vector2(cos(a), sin(a)) * ring_r)
+	NeonDraw.draw_glowing_polygon(self, ring, _active_color(), pulse, core_color)
+
+	var box: float = 4.2 * s
+	NeonDraw.draw_glowing_polygon(self, PackedVector2Array([
+		center + Vector2(-box, -box), center + Vector2(box, -box),
+		center + Vector2(box, box), center + Vector2(-box, box),
+	]), _active_color(), pulse, core_color)
+
+	# Three stubby berths, so the ring reads as occupied rather than as a
+	# plain octagon.
+	for i in range(3):
+		var a: float = (float(i) / 3.0) * TAU - PI / 2.0
+		var dir: Vector2 = Vector2(cos(a), sin(a))
+		NeonDraw.draw_glowing_line(self, center + dir * (box * 1.5),
+			center + dir * (ring_r - 1.5 * s), _active_color(), pulse, 0.35 * s, core_color)
+
+
 func _draw_crafter_icon(center: Vector2, pulse: float, s: float) -> void:
 	# Reactor core, truss spine, and an open cradle holding a hull.
 	var core_centre: Vector2 = center + Vector2(-11, 0) * s

Main.tscn

@@ -270,10 +270,10 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = -214
+offset_left = -204
-offset_right = -66
+offset_right = -76
-offset_top = -254
+offset_top = -300
-offset_bottom = -106
+offset_bottom = -172
 script = ExtResource("10")
 icon = 8
 glow_color = Color(0.45, 0.9, 0.55, 1)
@@ -286,9 +286,9 @@ anchor_top = 0.5
 anchor_bottom = 0.5
 offset_left = -290
 offset_right = 10
-offset_top = -96
+offset_top = -166
-offset_bottom = 4
+offset_bottom = -100
-theme_override_font_sizes/font_size = 36
+theme_override_font_sizes/font_size = 32
 autowrap_mode = 2
 text = "Mothership"
 horizontal_alignment = 1
@@ -299,23 +299,23 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = -204
+offset_left = -200
-offset_right = -64
+offset_right = -80
-offset_top = 14
+offset_top = -96
-offset_bottom = 78
+offset_bottom = -44
 script = ExtResource("19")
 amount = 20
-digit_height = 52.0
+digit_height = 40.0
 
 [node name="CrafterButton" type="Control" parent="UI/BuildMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = 66
+offset_left = 76
-offset_right = 214
+offset_right = 204
-offset_top = -254
+offset_top = -300
-offset_bottom = -106
+offset_bottom = -172
 script = ExtResource("10")
 icon = 9
 glow_color = Color(1, 0.72, 0.25, 1)
@@ -328,9 +328,9 @@ anchor_top = 0.5
 anchor_bottom = 0.5
 offset_left = -10
 offset_right = 290
-offset_top = -96
+offset_top = -166
-offset_bottom = 4
+offset_bottom = -100
-theme_override_font_sizes/font_size = 36
+theme_override_font_sizes/font_size = 32
 autowrap_mode = 2
 text = "Ship Crafter"
 horizontal_alignment = 1
@@ -341,23 +341,23 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = 76
+offset_left = 80
-offset_right = 216
+offset_right = 200
-offset_top = 14
+offset_top = -96
-offset_bottom = 78
+offset_bottom = -44
 script = ExtResource("19")
 amount = 12
-digit_height = 52.0
+digit_height = 40.0
 
 [node name="CommandButton" type="Control" parent="UI/BuildMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = -214
+offset_left = -204
-offset_right = -66
+offset_right = -76
-offset_top = 118
+offset_top = -10
-offset_bottom = 266
+offset_bottom = 118
 script = ExtResource("10")
 icon = 10
 glow_color = Color(0.55, 0.6, 1, 1)
@@ -370,9 +370,9 @@ anchor_top = 0.5
 anchor_bottom = 0.5
 offset_left = -290
 offset_right = 10
-offset_top = 276
+offset_top = 124
-offset_bottom = 376
+offset_bottom = 190
-theme_override_font_sizes/font_size = 36
+theme_override_font_sizes/font_size = 32
 autowrap_mode = 2
 text = "Command Center"
 horizontal_alignment = 1
@@ -383,23 +383,23 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = -204
+offset_left = -200
-offset_right = -64
+offset_right = -80
-offset_top = 386
+offset_top = 194
-offset_bottom = 450
+offset_bottom = 246
 script = ExtResource("19")
 amount = 15
-digit_height = 52.0
+digit_height = 40.0
 
 [node name="ExtractorButton" type="Control" parent="UI/BuildMenu"]
 anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = 66
+offset_left = 76
-offset_right = 214
+offset_right = 204
-offset_top = 118
+offset_top = -10
-offset_bottom = 266
+offset_bottom = 118
 script = ExtResource("10")
 icon = 11
 glow_color = Color(0, 0.62, 0.7, 1)
@@ -412,9 +412,9 @@ anchor_top = 0.5
 anchor_bottom = 0.5
 offset_left = -10
 offset_right = 290
-offset_top = 276
+offset_top = 124
-offset_bottom = 376
+offset_bottom = 190
-theme_override_font_sizes/font_size = 36
+theme_override_font_sizes/font_size = 32
 autowrap_mode = 2
 text = "Extractor"
 horizontal_alignment = 1
@@ -425,13 +425,55 @@ anchor_left = 0.5
 anchor_right = 0.5
 anchor_top = 0.5
 anchor_bottom = 0.5
-offset_left = 76
+offset_left = 80
-offset_right = 216
+offset_right = 200
-offset_top = 386
+offset_top = 194
-offset_bottom = 450
+offset_bottom = 246
 script = ExtResource("19")
 amount = 25
-digit_height = 52.0
+digit_height = 40.0
+
+[node name="TransportHubButton" type="Control" parent="UI/BuildMenu"]
+anchor_left = 0.5
+anchor_right = 0.5
+anchor_top = 0.5
+anchor_bottom = 0.5
+offset_left = -64
+offset_right = 64
+offset_top = 280
+offset_bottom = 408
+script = ExtResource("10")
+icon = 12
+glow_color = Color(0.95, 0.55, 0.85, 1)
+
+[node name="TransportHubLabel" 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 = -150
+offset_right = 150
+offset_top = 414
+offset_bottom = 480
+theme_override_font_sizes/font_size = 32
+autowrap_mode = 2
+text = "Transport Hub"
+horizontal_alignment = 1
+
+[node name="TransportHubCost" 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 = -60
+offset_right = 60
+offset_top = 484
+offset_bottom = 536
+script = ExtResource("19")
+amount = 30
+digit_height = 40.0
 
 [node name="CloseButton" type="Control" parent="UI/BuildMenu"]
 anchor_left = 1.0

WorldMapContent.gd

@@ -10,6 +10,7 @@ const WORLD_TO_LOCAL: float = 0.04
 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)
 
 # 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,
@@ -50,6 +51,8 @@ func _building_marker_color(type: String) -> Color:
 			return MOTHERSHIP_MARKER_COLOR
 		GameState.BUILDING_SHIP_CRAFTER:
 			return CRAFTER_MARKER_COLOR
+		GameState.BUILDING_TRANSPORT_HUB:
+			return TRANSPORT_HUB_MARKER_COLOR
 		_:
 			return COMMAND_MARKER_COLOR
 
@@ -115,6 +118,8 @@ func _draw() -> void:
 				_draw_marker_polygon(_regular_polygon(marker.position, 8.0, 6, PI / 6.0), marker.color)
 			GameState.BUILDING_SHIP_CRAFTER:
 				_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)
 			_:
 				_draw_marker_polygon(_regular_polygon(marker.position, 6.0, 4, PI / 4.0), marker.color)
 

tests/_build_menu_preview.gd

@@ -0,0 +1,20 @@
+extends Node2D
+
+# Preview, not a test. Opens the build menu itself, so the three-row layout
+# added for the Transport Hub (#18) can be checked for fit on the real phone
+# viewport - every button, label and price moved, and a bad offset is
+# invisible to a headless test.
+#
+#   bash tests/screenshot.sh res://tests/_build_menu_preview.tscn /tmp/menu.png 20 720x1280
+
+
+func _ready() -> void:
+	GameState.buildings.clear()
+	GameState.extractors.clear()
+	GameState.rocks = 500
+	# Everything researched, so nothing is greyed out and the whole menu is
+	# legible at full strength.
+	GameState.unlocked = ["shipyards", "logistics", "freight", "coordination"]
+	var main: Node = load("res://Main.tscn").instantiate()
+	add_child(main)
+	main.get_node("UI/BuildMenu").visible = true

tests/_build_menu_preview.tscn

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

tests/_ingame_buildings_preview.gd

@@ -13,8 +13,9 @@ func _ready() -> void:
 	GameState.buildings.clear()
 	GameState.extractors.clear()
 	GameState.reset_formation()
-	GameState.add_building(GameState.BUILDING_MOTHERSHIP, Vector2(-230.0, 0.0))
+	GameState.add_building(GameState.BUILDING_MOTHERSHIP, Vector2(-330.0, 0.0))
-	GameState.add_building(GameState.BUILDING_SHIP_CRAFTER, Vector2(240.0, 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))
 
 	var main: Node = load("res://Main.tscn").instantiate()
 	add_child(main)
@@ -24,4 +25,4 @@ func _ready() -> void:
 	# far enough to see them whole.
 	main.get_node("Fleet").move_to(Vector2(0.0, 210.0))
 	var cam: Camera2D = main.get_node("Camera2D")
-	cam.zoom = Vector2(1.35, 1.35)
+	cam.zoom = Vector2(1.0, 1.0)

tests/test_transport_hub_building.gd

@@ -0,0 +1,157 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_transport_hub_building.gd
+# Forgejo #18 (part 5 of #12): the Transport Hub is a placeable building of
+# its own. Only the building here - the vessels that do the hauling are #19.
+#
+# Verifies:
+#   1. it is gated behind its research node, like every other structure
+#   2. researching it makes it buildable, and placing it charges its cost
+#   3. it is drawn as ITSELF, not as the crafter - Building._draw()'s match
+#      has a catch-all that renders anything unrecognised as a ship crafter,
+#      so a missing case is silent and looks almost right
+#   4. its geometry is rasterised ONCE however long it animates (#10), and
+#      its stationed transports really do move
+#   5. it has its own build-menu icon and its own map marker rather than
+#      borrowing another building's - the menu was once unreadable because
+#      two buildings shared a glyph
+
+var game_state: Node
+var scene: Node
+var field: Node
+var controller: Node
+var map_content: Node2D
+var hub: Node2D
+var stage: int = 0
+var elapsed: float = 0.0
+var spin_at_start: float = 0.0
+
+const HUB_AT: Vector2 = Vector2(700.0, 0.0)
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+	game_state.buildings.clear()
+	game_state.extractors.clear()
+	game_state.reset_progression()
+	game_state.rocks = 500
+	game_state.fleet_cargo = 0
+	scene = load("res://Main.tscn").instantiate()
+	root.add_child(scene)
+	field = scene.get_node("BuildingField")
+	controller = scene.get_node("BuildController")
+	map_content = scene.get_node("UI/WorldMap/MapContent")
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			scene.get_node("AsteroidField").set_process(false)
+			scene.get_node("EnemySpawner").set_process(false)
+
+			# --- 1. locked until researched ------------------------------
+			if game_state.is_building_unlocked(GameState.BUILDING_TRANSPORT_HUB):
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (buildable with no research at all)")
+				quit(1)
+				return true
+			var gate: String = game_state.research_for_building(GameState.BUILDING_TRANSPORT_HUB)
+			if gate == "":
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (no research node gates it)")
+				quit(1)
+				return true
+			print("locked behind research: '%s'" % gate)
+
+			# --- 5. its own icon, distinct from every other building -----
+			var icons: Dictionary = {}
+			for type in [GameState.BUILDING_MOTHERSHIP, GameState.BUILDING_SHIP_CRAFTER,
+					GameState.BUILDING_COMMAND_CENTER, GameState.BUILDING_TRANSPORT_HUB]:
+				var icon: int = controller._action_icon_for(type)
+				if icons.has(icon):
+					print("TEST_TRANSPORT_HUB_BUILDING: FAIL (%s and %s share an icon)" % [type, icons[icon]])
+					quit(1)
+					return true
+				icons[icon] = type
+			print("action icons distinct across %d buildings" % icons.size())
+
+			# --- 2. research it, then build it ---------------------------
+			game_state.unlocked = ["shipyards", "logistics", "freight"]
+			if not game_state.is_building_unlocked(GameState.BUILDING_TRANSPORT_HUB):
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (still locked after researching '%s')" % gate)
+				quit(1)
+				return true
+			var before: int = game_state.rocks
+			field.place(GameState.BUILDING_TRANSPORT_HUB, HUB_AT)
+			game_state.spend(controller.cost_of(GameState.BUILDING_TRANSPORT_HUB))
+			if game_state.rocks != before - GameState.TRANSPORT_HUB_COST:
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (cost %d charged, expected %d)" % [
+					before - game_state.rocks, GameState.TRANSPORT_HUB_COST
+				])
+				quit(1)
+				return true
+			print("researched and placed for %d ore" % GameState.TRANSPORT_HUB_COST)
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			if elapsed < 0.3:
+				return false
+			for b in field.spawned:
+				if is_instance_valid(b) and b.building_type == GameState.BUILDING_TRANSPORT_HUB:
+					hub = b
+			if hub == null:
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (never spawned)")
+				quit(1)
+				return true
+
+			# --- 3. drawn as itself, not via the crafter catch-all -------
+			# _hub_traffic only exists if _ready() took the transport-hub
+			# branch; a missing case falls through to the crafter and would
+			# leave it null while still rendering something plausible.
+			if hub._hub_traffic == null:
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (rendered through the crafter catch-all, not as a hub)")
+				quit(1)
+				return true
+
+			# --- 5. its own map marker ----------------------------------
+			var markers: Array = map_content.building_markers()
+			var found: bool = false
+			for m in markers:
+				if m.type == GameState.BUILDING_TRANSPORT_HUB:
+					found = true
+					if m.color == map_content.CRAFTER_MARKER_COLOR \
+							or m.color == map_content.MOTHERSHIP_MARKER_COLOR \
+							or m.color == map_content.COMMAND_MARKER_COLOR:
+						print("TEST_TRANSPORT_HUB_BUILDING: FAIL (map marker reuses another building's colour)")
+						quit(1)
+						return true
+			if not found:
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (no map marker - see #11)")
+				quit(1)
+				return true
+			print("has its own map marker")
+
+			spin_at_start = hub._hub_traffic.rotation
+			elapsed = 0.0
+			stage = 2
+			return false
+		2:
+			# --- 4. animates without ever redrawing (#10) ----------------
+			if elapsed < 2.0:
+				return false
+			print("rasterisations after %.1fs: %d" % [elapsed, hub.draw_count])
+			if hub.draw_count != 1:
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (redrew its geometry %d times to animate)" % hub.draw_count)
+				quit(1)
+				return true
+			var spun: float = absf(hub._hub_traffic.rotation - spin_at_start)
+			print("stationed transports turned %.3f rad" % spun)
+			if spun < 0.05:
+				print("TEST_TRANSPORT_HUB_BUILDING: FAIL (nothing moved - a frozen hub trivially passes the redraw check)")
+				quit(1)
+				return true
+			print("TEST_TRANSPORT_HUB_BUILDING: PASS")
+			quit(0)
+			return true
+	return false