P4 hazards: food spoilage with rot speed setting, smoking rack and salt, food poisoning, harsher blizzards, hard winters with lake ice, lightning on trees, snow on roofs (protocol 11)

scripts/world/weather.gd

@@ -11,6 +11,11 @@ extends Node
 ## (and a storm becomes a blizzard). Above the snowline it always snows.
 ## Outputs ease toward the state's targets over about a minute, so fronts
 ## roll in rather than switching.
+##
+## P4 (docs/PROGRESSION_DESIGN.md §5): every 12 days a hard winter, three
+## bitter cold days in a row (hard_winter()), colder still, with more snow and
+## blizzards. A blizzard cuts visibility right down and its wind strips the
+## warmth from anyone out in it (blizzard_chill(); a shelter keeps it out).
 
 signal state_changed(state: String)
 
@@ -30,12 +35,18 @@ const TARGETS := {
 	"rain":     {"clouds": 0.92, "precip": 0.6, "wind": 0.60, "light": 0.50, "fog": 2.2, "warmth": -6.0},
 	"storm":    {"clouds": 1.00, "precip": 1.0, "wind": 1.00, "light": 0.30, "fog": 3.0, "warmth": -12.0},
 	"snow":     {"clouds": 0.90, "precip": 0.6, "wind": 0.35, "light": 0.68, "fog": 2.6, "warmth": -14.0},
-	"blizzard": {"clouds": 1.00, "precip": 1.0, "wind": 0.90, "light": 0.45, "fog": 4.5, "warmth": -24.0},
+	"blizzard": {"clouds": 1.00, "precip": 1.0, "wind": 1.00, "light": 0.40, "fog": 7.0, "warmth": -24.0},
 }
 const COLD_DAY_WARMTH := -8.0
 const BLEND_SECONDS := 50.0      ## time for outputs to cross from one state to another
 const CALM_START := 600.0        ## a new world's first 10 minutes are always clear
 const COLD_DAY_CHANCE := 0.25
+const HARD_WINTER_EVERY := 12     ## days 12-14, 24-26, ...
+const HARD_WINTER_DAYS := 3
+const HARD_WINTER_WARMTH := -8.0  ## on top of a cold day's
+const BLIZZARD_CHILL := 18.0      ## more warmth lost out in a blizzard's wind (a hard winter's freezes you by day)
+## In a hard winter the weather leans wet (more snow and blizzards).
+const HARD_WINTER_FRONT := -0.18
 
 var world_seed := 1337
 var day_night: Node
@@ -76,9 +87,22 @@ func setup(seed: int, dn: Node) -> void:
 func world_seconds() -> float:
 	return (float(day_night.day - 1) + float(day_night.time)) * float(day_night.day_length)
 
+## Day `day` is one of a hard winter's three bitter days.
+static func hard_winter(day: int) -> bool:
+	return day >= HARD_WINTER_EVERY and (day - HARD_WINTER_EVERY) % HARD_WINTER_EVERY < HARD_WINTER_DAYS
+
+## The first day of the next hard winter on or after `day`.
+static func next_hard_winter(day: int) -> int:
+	var d := maxi(day, HARD_WINTER_EVERY)
+	while not hard_winter(d):
+		d += 1
+	return d
+
 func is_cold_day(day: int) -> bool:
 	if day <= 1:
 		return false
+	if hard_winter(day):
+		return true
 	return float(absi(hash(Vector2i(world_seed, day))) % 10000) / 10000.0 < COLD_DAY_CHANCE
 
 ## The raw front value at an absolute time (higher = fairer).
@@ -100,7 +124,7 @@ func _state_for(v: float, cold: bool) -> String:
 ## The state at an absolute time, ignoring smoothing and overrides.
 func state_at(t: float) -> String:
 	var day := int(floor(t / float(day_night.day_length))) + 1
-	return _state_for(front_at(t), is_cold_day(day))
+	return _state_for(front_at(t) + (HARD_WINTER_FRONT if hard_winter(day) else 0.0), is_cold_day(day))
 
 func force(s: String) -> void:
 	override = s
@@ -116,7 +140,7 @@ func snap() -> void:
 	wind = tg.wind
 	light = tg.light
 	fog = tg.fog
-	warmth = tg.warmth + (COLD_DAY_WARMTH if cold_day else 0.0)
+	warmth = tg.warmth + _cold_extra()
 	ground_wet = 1.0 if state in ["rain", "storm"] else 0.0
 	snow_cover = 0.7 if state in ["snow", "blizzard"] else (0.25 if cold_day else 0.0)
 
@@ -128,7 +152,7 @@ func _pick_state() -> void:
 	if frozen and s.is_empty():
 		s = "clear"
 	if s.is_empty():
-		s = _state_for(front_at(world_seconds()), cold_day)
+		s = _state_for(front_at(world_seconds()) + (HARD_WINTER_FRONT if hard_winter(day_night.day) else 0.0), cold_day)
 	if s != state:
 		state = s
 		state_changed.emit(state)
@@ -145,7 +169,7 @@ func step(dt: float) -> void:
 	wind = move_toward(wind, tg.wind, k)
 	light = move_toward(light, tg.light, k * 0.8)
 	fog = move_toward(fog, tg.fog, k * 3.0)
-	warmth = move_toward(warmth, tg.warmth + (COLD_DAY_WARMTH if cold_day else 0.0), k * 20.0)
+	warmth = move_toward(warmth, tg.warmth + _cold_extra(), k * 20.0)
 	# The ground soaks in a couple of minutes of rain and dries over ten.
 	var raining := precip > 0.2 and not snowing_globally()
 	ground_wet = move_toward(ground_wet, 1.0 if raining else 0.0, dt / (120.0 if raining else 600.0))
@@ -163,6 +187,22 @@ func step(dt: float) -> void:
 			flash = 1.0
 			lightning_count += 1
 
+## Extra cold from the day: a cold day, and a hard winter on top.
+func _cold_extra() -> float:
+	if not cold_day:
+		return 0.0
+	return COLD_DAY_WARMTH + (HARD_WINTER_WARMTH if day_night != null and hard_winter(day_night.day) else 0.0)
+
+func in_hard_winter() -> bool:
+	return day_night != null and hard_winter(day_night.day)
+
+## Extra warmth lost by someone out in a blizzard's wind (0 when sheltered or
+## when it isn't blowing).
+func blizzard_chill(sheltered: bool) -> float:
+	if sheltered or state != "blizzard":
+		return 0.0
+	return BLIZZARD_CHILL * clampf(precip, 0.0, 1.0)
+
 func snowing_globally() -> bool:
 	return state in ["snow", "blizzard"]
 
@@ -188,4 +228,6 @@ func label() -> String:
 	var s: String = names[state]
 	if cold_day and state in ["clear", "cloudy"]:
 		s += ", cold"
+	if in_hard_winter():
+		s += " (hard winter)"
 	return s