Validate POC A and POC B foundations

src/survival_model.gd

@@ -0,0 +1,139 @@
+class_name SurvivalModel
+extends RefCounted
+
+enum AlertLevel {
+	NORMAL,
+	CAUTION,
+	RETURN,
+	CRITICAL,
+	EMPTY,
+}
+
+const DEFAULT_OXYGEN_SECONDS := 600.0
+const DEFAULT_BATTERY := 100.0
+const DEFAULT_HULL := 100.0
+const DEFAULT_NOMINAL_DEPTH := 60.0
+const DEFAULT_CRITICAL_DEPTH := 72.0
+const DEFAULT_CRUSH_DEPTH := 78.0
+
+var oxygen_max := DEFAULT_OXYGEN_SECONDS
+var battery_max := DEFAULT_BATTERY
+var hull_max := DEFAULT_HULL
+
+var oxygen := DEFAULT_OXYGEN_SECONDS
+var battery := DEFAULT_BATTERY
+var hull := DEFAULT_HULL
+
+var nominal_depth := DEFAULT_NOMINAL_DEPTH
+var critical_depth := DEFAULT_CRITICAL_DEPTH
+var crush_depth := DEFAULT_CRUSH_DEPTH
+
+var oxygen_drain_per_second := 1.0
+var battery_drain_per_second_at_full_thrust := 0.60
+
+
+func reset() -> void:
+	oxygen = oxygen_max
+	battery = battery_max
+	hull = hull_max
+
+
+func tick(delta: float, thrust_ratio: float, depth: float, collision_damage: float = 0.0) -> Dictionary:
+	if delta <= 0.0:
+		return snapshot(depth)
+
+	oxygen = maxf(0.0, oxygen - oxygen_drain_per_second * delta)
+	battery = maxf(
+		0.0,
+		battery - battery_drain_per_second_at_full_thrust * clampf(thrust_ratio, 0.0, 1.0) * delta
+	)
+
+	if depth > nominal_depth:
+		if depth >= crush_depth:
+			hull -= 25.0 * delta
+		else:
+			var pressure_range := maxf(critical_depth - nominal_depth, 0.001)
+			var pressure_ratio := clampf((depth - nominal_depth) / pressure_range, 0.0, 1.0)
+			var damage_rate := lerpf(0.15, 5.0, pressure_ratio * pressure_ratio)
+			if depth > critical_depth:
+				var critical_ratio := (depth - critical_depth) / maxf(crush_depth - critical_depth, 0.001)
+				damage_rate = lerpf(5.0, 18.0, clampf(critical_ratio, 0.0, 1.0))
+			hull -= damage_rate * delta
+
+	hull = clampf(hull - maxf(collision_damage, 0.0), 0.0, hull_max)
+	return snapshot(depth)
+
+
+func snapshot(depth: float) -> Dictionary:
+	return {
+		"oxygen": oxygen,
+		"oxygen_max": oxygen_max,
+		"oxygen_ratio": _ratio(oxygen, oxygen_max),
+		"battery": battery,
+		"battery_max": battery_max,
+		"battery_ratio": _ratio(battery, battery_max),
+		"hull": hull,
+		"hull_max": hull_max,
+		"hull_ratio": _ratio(hull, hull_max),
+		"depth": maxf(depth, 0.0),
+		"nominal_depth": nominal_depth,
+		"critical_depth": critical_depth,
+		"crush_depth": crush_depth,
+		"oxygen_alert": alert_level(oxygen, oxygen_max),
+		"battery_alert": alert_level(battery, battery_max),
+		"hull_alert": alert_level(hull, hull_max),
+		"depth_alert": depth_alert_level(depth),
+		"loss_reason": loss_reason(),
+	}
+
+
+func loss_reason() -> StringName:
+	if hull <= 0.0:
+		return &"hull_failure"
+	if oxygen <= 0.0:
+		return &"oxygen_depleted"
+	return &""
+
+
+func alert_level(value: float, maximum: float) -> AlertLevel:
+	var ratio := _ratio(value, maximum)
+	if ratio <= 0.0:
+		return AlertLevel.EMPTY
+	if ratio <= 0.05:
+		return AlertLevel.CRITICAL
+	if ratio <= 0.15:
+		return AlertLevel.RETURN
+	if ratio <= 0.30:
+		return AlertLevel.CAUTION
+	return AlertLevel.NORMAL
+
+
+func depth_alert_level(depth: float) -> AlertLevel:
+	if depth >= crush_depth:
+		return AlertLevel.EMPTY
+	if depth >= critical_depth:
+		return AlertLevel.CRITICAL
+	if depth > nominal_depth:
+		return AlertLevel.RETURN
+	if depth >= nominal_depth * 0.85:
+		return AlertLevel.CAUTION
+	return AlertLevel.NORMAL
+
+
+func estimated_return_energy(distance: float, vertical_gain: float = 0.0) -> float:
+	var seconds_at_cruise := maxf(distance, 0.0) / 6.0
+	var base_cost := seconds_at_cruise * battery_drain_per_second_at_full_thrust
+	var vertical_cost := maxf(vertical_gain, 0.0) * 0.035
+	return base_cost + vertical_cost
+
+
+func force_critical_state() -> void:
+	oxygen = minf(oxygen, 30.0)
+	battery = minf(battery, 12.0)
+	hull = minf(hull, 28.0)
+
+
+func _ratio(value: float, maximum: float) -> float:
+	if maximum <= 0.0:
+		return 0.0
+	return clampf(value / maximum, 0.0, 1.0)