South town MVP: world sim, seasons, granary, contrast test + findings

Godot 4.7 C# world simulation per SPEC.md (with 2026-07-21 amendments). 15 NPCs, 5-state machine, demand-driven work, soul-imprint triad data model, seasons with winter frost, granary, need-based gift economy, selfish-soul contrast wiring, daily/per-villager/gift CSV logging. FINDINGS.md documents the four soak experiments: the dead paradise, the buffers winning, the emergent hungry gap, and the contrast test proving the four-town thesis (and that selfishness wins until the soul-consequence layer exists). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-21 12:55:30 -04:00
commit 721acbd1aa
31 changed files with 5661 additions and 0 deletions
@@ -0,0 +1,64 @@
+namespace WorldSim;
+
+/// <summary>
+/// Trade evaluation and execution (SPEC §9). South MVP: generous, voluntary,
+/// no currency — a gift economy where the ratio favors the receiver.
+///
+/// Soul consequences: a generous completed exchange eases both parties'
+/// imprints (external perception — the world pressed kindly on them).
+/// Later soul types change the ratio logic only; the mechanism is shared.
+/// </summary>
+public static class TradeSystem
+{
+    /// <summary>Trades since the last daily stats snapshot.</summary>
+    public static int TradesToday;
+
+    /// <summary>
+    /// Need-based: the trigger is a person in need, not an inventory gap.
+    /// Food flows to the hungry first; raw material surplus vs. genuine
+    /// lack remains as a fallback.
+    /// </summary>
+    public static bool CanTrade(Npc giver, Npc receiver, out MaterialKind material)
+    {
+        material = MaterialKind.Food;
+
+        // The ungenerous do not give. Not from an empty pack — from a full one.
+        if (giver.Soul.Generosity < 0.3f) return false;
+
+        giver.Inventory.TryGetValue(MaterialKind.Food, out float giverFood);
+        receiver.Inventory.TryGetValue(MaterialKind.Food, out float receiverFood);
+        if (receiver.Nourishment < 0.6f && receiverFood < 2f && giverFood > 3f)
+            return true;
+
+        foreach (var kv in giver.Inventory)
+        {
+            bool receiverLacks = !receiver.Inventory.TryGetValue(kv.Key, out float has) || has < 2f;
+            if (kv.Value > 5f && receiverLacks) { material = kv.Key; return true; }
+        }
+        return false;
+    }
+
+    public static void Execute(Npc giver, Npc receiver, MaterialKind material)
+    {
+        TradesToday++;
+
+        // Generosity decides how much of the surplus is given.
+        float surplus = giver.Inventory[material] - 2f;
+        float given = surplus * giver.Soul.Generosity;
+
+        giver.Inventory[material] -= given;
+        receiver.Inventory.TryGetValue(material, out float has);
+        receiver.Inventory[material] = has + given;
+
+        StatsLogger.LogGift(giver, receiver, material, given);
+
+        // The kindness lands on both atmospheres — gently.
+        giver.Imprint.ExternalPerception    -= 0.002f;
+        receiver.Imprint.ExternalPerception -= 0.002f;
+        giver.Imprint.Clamp();
+        receiver.Imprint.Clamp();
+
+        // TODO(Week 3): soul-imprint-weighted PARTNER selection (trusted vs
+        // tainted history) — the constrained-emergence reference pattern (SPEC §7).
+    }
+}