M1b: survival stats, day/night, fire fuel, cooking, foraging, torches, death + grave

- Health, stamina, hunger, warmth and wet with HUD bars, status tags and clock
- 20-minute day/night cycle with moon, stars and lit clouds
- Campfire fuel (2 min start, 15 min max), heat radius, cooking needs a lit fire
- Berry bushes (regrow 10 min), mushrooms, roasted mushroom, torch
- Stamina costs for sprint, jump and harvest hits
- Death respawns at island start and leaves a grave bag
- Saves include stats, time of day, fire fuel, regrowth timers and graves
- New test_survival_stats suite; tests fail if a script error aborts them

scripts/building/campfire.gd

@@ -1,13 +1,24 @@
 extends "res://scripts/building/piece.gd"
-## Campfire: flickering light, flames, embers and smoke. A "campfire" station
-## (cooking arrives in M1b along with fuel and warmth).
+## Campfire: light, warmth and cooking, while it has fuel.
+##
+## Starts with a little kindling. E adds wood (or sticks) from your inventory;
+## it burns down in play time and goes out at zero. While lit it is a
+## "campfire" station (cooking) and a heat source (warmth within ~7 m).
 
+const MAX_FUEL := 900.0      ## 15 min
+const START_FUEL := 120.0
+const HEAT_RADIUS := 7.0
+
+var fuel := START_FUEL
 var _light: OmniLight3D
+var _fx: Array[CPUParticles3D] = []
 var _t := 0.0
 var _noise := FastNoiseLite.new()
+var _lit := true
 
 func _build() -> void:
 	add_to_group("station:campfire")
+	add_to_group("heat")
 	_noise.frequency = 2.5
 	_light = OmniLight3D.new()
 	_light.light_color = Color(1.0, 0.62, 0.3)
@@ -18,30 +29,76 @@ func _build() -> void:
 	_light.position = Vector3(0, 0.7, 0)
 	add_child(_light)
 
-	add_child(_particles("Flames", 26, 0.55, Vector3(0, 0.12, 0), 0.5, 1.0, 0.5, 0.9, _gradient([
+	_fx.append(_particles("Flames", 26, 0.55, Vector3(0, 0.12, 0), 0.5, 1.0, 0.5, 0.9, _gradient([
 		[0.0, Color(1.0, 0.8, 0.35, 0.0)], [0.15, Color(1.0, 0.62, 0.2, 0.75)],
 		[0.6, Color(0.95, 0.3, 0.06, 0.45)], [1.0, Color(0.5, 0.08, 0.02, 0.0)]]), true, 0.32, 0.12))
-	add_child(_particles("Embers", 10, 2.0, Vector3(0, 0.3, 0), 0.8, 2.0, 0.5, 1.0, _gradient([
+	_fx.append(_particles("Embers", 10, 2.0, Vector3(0, 0.3, 0), 0.8, 2.0, 0.5, 1.0, _gradient([
 		[0.0, Color(1.0, 0.75, 0.35, 1.0)], [1.0, Color(1.0, 0.3, 0.05, 0.0)]]), true, 0.04, 0.15))
-	var smoke := _particles("Smoke", 10, 5.0, Vector3(0, 1.0, 0), 0.6, 1.1, 0.6, 1.4, _gradient([
-		[0.0, Color(0.55, 0.54, 0.52, 0.0)], [0.25, Color(0.58, 0.57, 0.55, 0.07)],
-		[1.0, Color(0.7, 0.7, 0.7, 0.0)]]), false, 0.9, 0.15)
-	smoke.spread = 25.0
-	smoke.gravity = Vector3(0.35, 0.25, 0.1)   # drifts with the wind
-	# TODO(M1b): smoke renders as an opaque dark ball whatever its ramp colour
-	# (alpha-blended unshaded particles; additive flames are fine). Disabled
-	# until that's fixed, likely by moving to a small particle shader.
-	smoke.queue_free()
+	for p in _fx:
+		add_child(p)
+	# TODO: smoke. Alpha-blended unshaded particles rendered as an opaque dark
+	# ball whatever their ramp colour (additive flames are fine). Needs a small
+	# particle shader.
+	_set_lit(fuel > 0.0)
 
 func display_name() -> String:
 	return "Campfire"
 
+func is_lit() -> bool:
+	return _lit
+
+func station_active() -> bool:
+	return _lit
+
+## 0..1 warmth this fire gives at `pos`.
+func heat_at(pos: Vector3) -> float:
+	if not _lit:
+		return 0.0
+	return 1.0 - smoothstep(1.5, HEAT_RADIUS, pos.distance_to(global_position))
+
+func add_fuel(seconds: float) -> void:
+	fuel = minf(fuel + seconds, MAX_FUEL)
+	_set_lit(true)
+
+func interact_prompt(player: Node) -> String:
+	var has_fuel: bool = player.inventory.count("wood") + player.inventory.count("stick") > 0
+	if _lit:
+		var left := "%d:%02d" % [int(fuel) / 60, int(fuel) % 60]
+		return "Campfire (%s left)%s" % [left, "  [E] Add fuel" if has_fuel else "  (add wood or sticks)"]
+	return "Campfire (out)%s" % ("  [E] Add fuel to light" if has_fuel else "  (needs wood or sticks)")
+
+func interact(player: Node) -> void:
+	Actions.add_fuel(player, self)
+
 func _process(delta: float) -> void:
+	if not _lit:
+		return
+	fuel -= delta
+	if fuel <= 0.0:
+		fuel = 0.0
+		_set_lit(false)
+		return
 	_t += delta
 	var f := _noise.get_noise_1d(_t * 10.0)
-	_light.light_energy = 2.2 + f * 0.7
+	# Burns lower in its last minute.
+	var strength := clampf(fuel / 60.0, 0.35, 1.0)
+	_light.light_energy = (2.2 + f * 0.7) * strength
 	_light.position = Vector3(f * 0.05, 0.7 + f * 0.05, 0)
 
+func _set_lit(on: bool) -> void:
+	_lit = on
+	if _light != null:
+		_light.visible = on
+	for p in _fx:
+		p.emitting = on
+
+func save_extra() -> Dictionary:
+	return {"fuel": fuel}
+
+func load_extra(d: Dictionary) -> void:
+	fuel = float(d.get("fuel", fuel))
+	_set_lit(fuel > 0.0)
+
 static func _gradient(stops: Array) -> Gradient:
 	var g := Gradient.new()
 	g.offsets = PackedFloat32Array(stops.map(func(s): return s[0]))
@@ -61,7 +118,7 @@ static func _soft_dot() -> GradientTexture2D:
 	t.height = 64
 	return t
 
-func _particles(label: String, amount: int, lifetime: float, pos: Vector3, vmin: float, vmax: float,
+static func _particles(label: String, amount: int, lifetime: float, pos: Vector3, vmin: float, vmax: float,
 		smin: float, smax: float, ramp: Gradient, additive: bool, quad_size: float, radius: float) -> CPUParticles3D:
 	var p := CPUParticles3D.new()
 	p.name = label
@@ -81,7 +138,7 @@ func _particles(label: String, amount: int, lifetime: float, pos: Vector3, vmin:
 	# Flames shrink as they rise.
 	var curve := Curve.new()
 	curve.add_point(Vector2(0.0, 1.0))
-	curve.add_point(Vector2(1.0, 0.35 if additive else 1.6))
+	curve.add_point(Vector2(1.0, 0.35))
 	p.scale_amount_curve = curve
 	var quad := QuadMesh.new()
 	quad.size = Vector2.ONE * quad_size

scripts/building/grave.gd

@@ -0,0 +1,23 @@
+extends "res://scripts/building/piece.gd"
+## Grave: left where you died, holding everything you carried. Open it with E
+## to take your things back; it crumbles once empty.
+
+var inventory := Inventory.new(40)
+
+func _build() -> void:
+	inventory.changed.connect(_on_changed)
+
+func display_name() -> String:
+	return "Your grave"
+
+func interact_prompt(_player: Node) -> String:
+	return "Your grave  [E] Recover belongings"
+
+func interact(player: Node) -> void:
+	player.open_inventory(self)
+
+func _on_changed() -> void:
+	for s in inventory.slots:
+		if s != null:
+			return
+	queue_free.call_deferred()

scripts/building/grave.gd.uid

@@ -0,0 +1 @@
+uid://ok0js1e4pb4s