Fix the stop stutter, and hide unresearched buildings from the menu

Forgejo #13: releasing the stick paused, then moved again before
settling. stop() aims each ship at a braking point ahead of it, but the
ship's own velocity was ~0 - the anchor had been carrying it - so it
started from REST, accelerated into its own stopping distance, and
halted a second time. Measured: 0 -> 45 -> 90 -> 135 -> 180 -> brake.
stop() now hands the fleet's motion to the ship, so the release is one
continuous decelerating coast (222 -> 0) to the identical endpoint.
test_joystick_control now asserts the speed one frame after release is a
real fraction of cruise, and never rises afterwards.

Forgejo #21: unresearched structures are no longer listed greyed out.
They are hidden, and the menu repacks around what is left - a fixed grid
with entries hidden would otherwise leave holes where they used to be.
An entry alone on its row is centred rather than hanging in the left
column. Researched-but-not-usable is still shown greyed: an extractor
with no planet under the fleet is "not now", not "not yet".

This reverses a documented decision (the old comment argued that always
listing everything stops the player wondering whether the game has it at
all), so test_skill_tree's matching assertion was updated from
greyed-but-listed to hidden. The gate itself is unchanged and still
refuses a build forced past the menu.

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

BuildController.gd

@@ -28,6 +28,18 @@ 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_menu_entries: Array = [
+	[GameState.BUILDING_MOTHERSHIP, build_mothership_button,
+		get_node("../UI/BuildMenu/MothershipLabel"), get_node("../UI/BuildMenu/MothershipCost")],
+	[GameState.BUILDING_SHIP_CRAFTER, build_crafter_button,
+		get_node("../UI/BuildMenu/CrafterLabel"), get_node("../UI/BuildMenu/CrafterCost")],
+	[GameState.BUILDING_COMMAND_CENTER, build_command_button,
+		get_node("../UI/BuildMenu/CommandLabel"), get_node("../UI/BuildMenu/CommandCost")],
+	[GameState.BUILDING_EXTRACTOR, build_extractor_button,
+		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")],
+]
 @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")
@@ -185,6 +197,7 @@ func _process(delta: float) -> void:
 		# a planet lights the option up without reopening it.
 		build_extractor_button.enabled = _planet_under_fleet() != null \
 			and GameState.is_building_unlocked(GameState.BUILDING_EXTRACTOR)
+		build_extractor_button.queue_redraw()
 
 	if craft_menu.visible:
 		# Live, so a delivery arriving while the menu is open visibly works
@@ -266,14 +279,58 @@ func _planet_under_fleet() -> Node2D:
 	return planet_field.get_planet_fleet_is_on()
 
 
+# Grid geometry, shared with the layout below. Rows of two, and the menu is
+# rebuilt from whatever is currently researched (#21) rather than being a
+# fixed arrangement with holes punched in it.
+const MENU_ROW_TOPS: Array = [-300.0, -10.0, 280.0]
+const MENU_COL_X: float = 140.0
+const MENU_BUTTON_HALF: float = 64.0
+const MENU_BUTTON_H: float = 128.0
+const MENU_LABEL_HALF: float = 150.0
+const MENU_LABEL_H: float = 66.0
+const MENU_COST_HALF: float = 60.0
+const MENU_COST_H: float = 52.0
+
+
+func _place_entry(node: Control, cx: float, top: float, half: float, height: float) -> void:
+	node.offset_left = cx - half
+	node.offset_right = cx + half
+	node.offset_top = top
+	node.offset_bottom = top + height
+
+
+func _layout_build_menu() -> void:
+	# Structures the player has not researched are hidden outright (#21), and
+	# what remains is repacked so there are no gaps where they used to be.
+	# This reverses the earlier decision to always list everything greyed
+	# out; an option you cannot explain is apparently worse than one you
+	# cannot see yet.
+	var shown: Array = []
+	for entry in build_menu_entries:
+		var visible: bool = GameState.is_building_unlocked(entry[0])
+		entry[1].visible = visible
+		entry[2].visible = visible
+		entry[3].visible = visible
+		if visible:
+			shown.append(entry)
+
+	for i in range(shown.size()):
+		var row: int = i / 2
+		# Centred when it is the only one on its row, rather than hanging in
+		# the left column looking like something is missing beside it.
+		var alone: bool = (i == shown.size() - 1) and (i % 2 == 0)
+		var cx: float = 0.0 if alone else (-MENU_COL_X if i % 2 == 0 else MENU_COL_X)
+		var top: float = MENU_ROW_TOPS[mini(row, MENU_ROW_TOPS.size() - 1)]
+		_place_entry(shown[i][1], cx, top, MENU_BUTTON_HALF, MENU_BUTTON_H)
+		_place_entry(shown[i][2], cx, top + 134.0, MENU_LABEL_HALF, MENU_LABEL_H)
+		_place_entry(shown[i][3], cx, top + 204.0, MENU_COST_HALF, MENU_COST_H)
+
+
 func _refresh_build_status() -> void:
-	# Every option is always listed, greyed when it cannot be used - showing
-	# them only sometimes would leave the player wondering whether the game
-	# has them at all. Greyed buttons still emit `pressed`, so each one can
-	# 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)
+	_layout_build_menu()
+	# Researched but not usable right here is still shown, greyed: an
+	# extractor needs a planet under the fleet, which is a "not now" rather
+	# than a "not yet".
 	build_extractor_button.enabled = _planet_under_fleet() != null \
 		and GameState.is_building_unlocked(GameState.BUILDING_EXTRACTOR)
 

Fleet.gd

@@ -168,6 +168,14 @@ func stop() -> void:
 		# enough that ships always lag and always report motion, which is
 		# the only reason releasing the stick looked right.
 		var motion: Vector2 = ship.velocity + ship.fleet_velocity
+		# HAND THE FLEET'S MOTION TO THE SHIP. Until now the anchor was
+		# carrying it along and its own `velocity` was ~0, so aiming it at a
+		# braking point ahead made it start from REST: the fleet stopped
+		# dead, then accelerated into its own stopping distance and halted a
+		# second time. That is the "pause, then it moves again" stutter.
+		# Giving it the velocity it was actually travelling at makes the
+		# stop one continuous decelerating coast.
+		ship.velocity = motion
 		# Context that is no longer true: the fleet is not cruising any
 		# more, so leaving it set would have Ship face a heading it is not
 		# travelling on.

tests/_build_menu_preview.gd

@@ -14,7 +14,9 @@ func _ready() -> void:
 	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"]
+	# Partly researched, to show the menu repacking around what is hidden.
+	GameState.unlocked = ["shipyards", "logistics"]
 	var main: Node = load("res://Main.tscn").instantiate()
 	add_child(main)
 	main.get_node("UI/BuildMenu").visible = true
+	main.get_node("BuildController")._refresh_build_status()

tests/test_build_menu_hides_locked.gd

@@ -0,0 +1,135 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_build_menu_hides_locked.gd
+# Forgejo #21: a structure the player has not researched should not be in the
+# build menu at all, rather than sitting there greyed out.
+#
+# The menu is a fixed grid in Main.tscn, so simply hiding entries would leave
+# holes where they used to be - it is repacked from whatever is researched.
+#
+# Verifies:
+#   1. with nothing researched only the mothership is offered (it is
+#      deliberately never gated - it is where research happens)
+#   2. researching a structure adds it, and it is placed, not left at
+#      whatever offsets it happened to have in the scene file
+#   3. no gaps: what is shown occupies consecutive grid slots
+#   4. an entry alone on its row is centred, not hanging in the left column
+#   5. researched-but-not-usable is still shown greyed (an extractor with no
+#      planet under the fleet is "not now", not "not yet")
+
+var game_state: Node
+var scene: Node
+var controller: 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.reset_progression()
+	game_state.rocks = 500
+	scene = load("res://Main.tscn").instantiate()
+	root.add_child(scene)
+	controller = scene.get_node("BuildController")
+
+
+func _shown() -> Array:
+	var out: Array = []
+	for entry in controller.build_menu_entries:
+		if entry[1].visible:
+			out.append(entry)
+	return out
+
+
+func _slots() -> Array:
+	# (row, x) of every visible button, in menu order.
+	var out: Array = []
+	for entry in _shown():
+		var b: Control = entry[1]
+		out.append([b.offset_top, b.offset_left + (b.offset_right - b.offset_left) / 2.0])
+	return out
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			if elapsed < 0.2:
+				return false
+			scene.get_node("AsteroidField").set_process(false)
+			scene.get_node("EnemySpawner").set_process(false)
+
+			# --- 1. nothing researched ----------------------------------
+			controller._refresh_build_status()
+			var shown: Array = _shown()
+			if shown.size() != 1 or shown[0][0] != GameState.BUILDING_MOTHERSHIP:
+				var names: Array = []
+				for e in shown:
+					names.append(e[0])
+				print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (unresearched structures on offer: %s)" % [names])
+				quit(1)
+				return true
+			# --- 4. and it is centred, being alone on its row -----------
+			var only: Array = _slots()[0]
+			if absf(only[1]) > 0.01:
+				print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (the only entry sits at x=%.1f instead of centred)" % only[1])
+				quit(1)
+				return true
+			print("nothing researched -> only the mothership, centred")
+
+			# --- 2. research three more ---------------------------------
+			game_state.unlocked = ["shipyards", "logistics", "coordination"]
+			controller._refresh_build_status()
+			stage = 1
+			return false
+		1:
+			var shown2: Array = _shown()
+			if shown2.size() != 4:
+				print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (researched 3, expected 4 entries, got %d)" % shown2.size())
+				quit(1)
+				return true
+			for e in shown2:
+				if e[0] == GameState.BUILDING_TRANSPORT_HUB:
+					print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (the unresearched transport hub is still listed)")
+					quit(1)
+					return true
+
+			# --- 3. consecutive slots, no holes -------------------------
+			var slots: Array = _slots()
+			var rows: Array = controller.MENU_ROW_TOPS
+			for i in range(slots.size()):
+				var want_row: float = rows[i / 2]
+				if absf(slots[i][0] - want_row) > 0.01:
+					print("slot %d at y=%.1f, expected row %d at y=%.1f" % [i, slots[i][0], i / 2, want_row])
+					print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (a gap was left where a hidden entry used to be)")
+					quit(1)
+					return true
+				var want_x: float = -controller.MENU_COL_X if i % 2 == 0 else controller.MENU_COL_X
+				if absf(slots[i][1] - want_x) > 0.01:
+					print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (entry %d at x=%.1f, expected %.1f)" % [i, slots[i][1], want_x])
+					quit(1)
+					return true
+			print("4 entries packed into consecutive slots, no gaps")
+
+			# --- 5. researched but not usable is shown, greyed ----------
+			var extractor_shown: bool = false
+			for e in shown2:
+				if e[0] == GameState.BUILDING_EXTRACTOR:
+					extractor_shown = true
+					if e[1].enabled:
+						print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (extractor offered as usable with no planet under the fleet)")
+						quit(1)
+						return true
+			if not extractor_shown:
+				print("TEST_BUILD_MENU_HIDES_LOCKED: FAIL (researched extractor hidden - 'not now' is not 'not yet')")
+				quit(1)
+				return true
+			print("researched extractor shown but greyed, with no planet in reach")
+			print("TEST_BUILD_MENU_HIDES_LOCKED: PASS")
+			quit(0)
+			return true
+	return false

tests/test_joystick_control.gd

@@ -21,6 +21,11 @@ var elapsed: float = 0.0
 var start_centroid: Vector2
 var moving_centroid: Vector2
 var stop_check_frames: int = 0
+# Release-coast tracking (Forgejo #13).
+var released: bool = false
+var speed_at_release: float = 0.0
+var previous_speed: float = 0.0
+var accelerated_after_release: bool = false
 
 
 func _initialize() -> void:
@@ -54,8 +59,27 @@ func _release(local: Vector2) -> void:
 	joystick.handle_touch(ev)
 
 
+func _max_ship_speed() -> float:
+	var top: float = 0.0
+	for ship in fleet.ships:
+		top = maxf(top, ship.velocity.length())
+	return top
+
+
 func _process(delta: float) -> bool:
 	elapsed += delta
+
+	# Releasing the stick must be ONE continuous decelerating coast. It used
+	# to stop dead and then accelerate into its own stopping distance,
+	# halting a second time - felt in game as a pause followed by a small
+	# extra lurch (#13). The ships were being aimed at a braking point ahead
+	# while their own velocity was ~0, because the anchor had been carrying
+	# them, so they started from rest.
+	if released:
+		var now: float = _max_ship_speed()
+		if now > previous_speed + 1.0:
+			accelerated_after_release = true
+		previous_speed = now
 	match stage:
 		0:
 			main_scene.get_node("AsteroidField").set_process(false)
@@ -104,6 +128,9 @@ func _process(delta: float) -> bool:
 				return true
 
 			_release(joystick.size / 2.0)
+			released = true
+			speed_at_release = _max_ship_speed()
+			previous_speed = speed_at_release
 			if joystick.direction != Vector2.ZERO:
 				print("TEST_JOYSTICK_CONTROL: FAIL (direction not cleared on release)")
 				quit(1)
@@ -119,6 +146,20 @@ func _process(delta: float) -> bool:
 			var speed: float = 0.0
 			for ship in fleet.ships:
 				speed = max(speed, ship.velocity.length())
+			# Carrying the fleet's cruise speed, not starting from a standstill.
+			if speed_at_release < fleet.cruise_speed * 0.5:
+				print("speed one frame after release: %.1f (cruising at %.1f)" % [
+					speed_at_release, fleet.cruise_speed
+				])
+				print("TEST_JOYSTICK_CONTROL: FAIL (the fleet stopped dead on release instead of coasting)")
+				quit(1)
+				return true
+			if accelerated_after_release:
+				print("TEST_JOYSTICK_CONTROL: FAIL (the fleet sped up again after release - pause then lurch, #13)")
+				quit(1)
+				return true
+			print("release coast: %.1f -> 0 with no re-acceleration" % speed_at_release)
+
 			var stopped: bool = speed < 1.0
 			# Not merely "moved forward at all": the fleet cruises at
 			# cruise_speed and brakes at Ship.acceleration, so the coast is

tests/test_skill_tree.gd

@@ -8,8 +8,8 @@ extends SceneTree
 #
 # Verifies:
 #   1. from a fresh start only the mothership is buildable - the others are
-#      greyed, and pressing one explains which research opens it rather than
-#      silently failing
+#      not in the menu at all (#21 changed this from greyed-but-listed), and
+#      the gate still holds if the build is forced past the menu
 #   2. a locked option cannot be built even if the confirm is forced
 #   3. research costs rocks, needs its prerequisite, and unlocks its building
 #   4. the mothership's action button opens the tree (it used to have no
@@ -69,16 +69,16 @@ func _process(delta: float) -> bool:
 				return true
 
 			controller._on_build_pressed()
-			var greyed: bool = not scene.get_node("UI/BuildMenu/CrafterButton").enabled
+			# Since #21 an unresearched structure is not listed at all, rather
+			# than listed and greyed. It is therefore unreachable from the
+			# menu - but the popup must still refuse if something calls
+			# _on_place_crafter() by another route.
+			var hidden: bool = not scene.get_node("UI/BuildMenu/CrafterButton").visible
 			controller._on_place_crafter()
-			var explains: bool = popup.visible \
-				and "research" in popup.get_node("Panel/MessageLabel").text.to_lower()
 			var offered: bool = popup.get_node("Panel/BuildButton").visible
-			print("locked crafter: greyed=%s explains=%s confirm_offered=%s" % [
-				greyed, explains, offered
-			])
-			if not (greyed and explains) or offered:
-				print("TEST_SKILL_TREE: FAIL (locked option did not explain itself)")
+			print("locked crafter: hidden_from_menu=%s confirm_offered=%s" % [hidden, offered])
+			if not hidden or offered:
+				print("TEST_SKILL_TREE: FAIL (unresearched option still on offer)")
 				quit(1)
 				return true