feat: New theme + wire price adjustement

public/js/engine/engine.js

@@ -3,7 +3,7 @@
 // browser and in Node (tests, balance simulations).
 
 import { computeModifiers } from './effects.js';
-import { bulkCost, clamp, demandPerSecond, maxAffordable } from './formulas.js';
+import { bulkCost, clamp, demandPerSecond, materialBatch, maxAffordable } from './formulas.js';
 
 const MAX_STEP_SECONDS = 1;
 
@@ -38,6 +38,13 @@ export function derive(state, ctx) {
   }
 
   const demandMultiplier = mods.demand * rules.marketing.demandPerLevel ** state.marketing;
+  const batch = materialBatch(
+    rules.materialMarket,
+    state.totalProduced,
+    rate,
+    state.materialFactor,
+    mods.batchDiscount,
+  );
   return {
     clickYield: rules.click.yield * mods.click,
     perGenerator,
@@ -46,8 +53,8 @@ export function derive(state, ctx) {
     demand: demandPerSecond(rules.market, state.price, demandMultiplier),
     valueMultiplier: mods.value,
     materialPerUnit: rules.unit.materialPerUnit / mods.materialEfficiency,
-    batchSize: rules.materialMarket.batchSize,
-    batchCost: Math.ceil(rules.materialMarket.basePrice * state.materialFactor * mods.batchDiscount),
+    batchSize: batch.size,
+    batchCost: batch.cost,
     autoBuyMaterial: mods.autoBuyMaterial,
     marketingCost: Math.ceil(rules.marketing.baseCost * rules.marketing.costGrowth ** state.marketing),
   };
@@ -121,9 +128,12 @@ function stepMaterialMarket(state, ctx, dt, rng) {
   state.materialTimer += dt;
   while (state.materialTimer >= m.updateEverySeconds) {
     state.materialTimer -= m.updateEverySeconds;
-    const shock = 1 + (rng() - 0.5) * 2 * m.volatility;
+    let shock = 1 + (rng() - 0.5) * 2 * m.volatility;
+    if (rng() < m.spikeChance) shock *= rng() < 0.5 ? m.spikeSize : 1 / m.spikeSize; // shortage or glut
     const pulled = state.materialFactor + (1 - state.materialFactor) * m.reversion;
-    state.materialFactor = clamp(pulled * shock, m.minFactor, m.maxFactor);
+    const next = clamp(pulled * shock, m.minFactor, m.maxFactor);
+    state.materialTrend = Math.sign(next - state.materialFactor);
+    state.materialFactor = next;
   }
 }
 
@@ -137,9 +147,11 @@ function step(state, ctx, dt, rng, totals) {
   state.units += made;
   state.totalProduced += made;
 
-  // Automatic restock when the stock runs low.
-  if (d.autoBuyMaterial && state.material < d.batchSize / 2 && state.funds >= d.batchCost) {
-    buyMaterial(state, ctx);
+  // Automatic restock: patient while the price is high, urgent when nearly out.
+  if (d.autoBuyMaterial && state.funds >= d.batchCost) {
+    const { autoBuyBelowFactor } = ctx.rules.materialMarket;
+    const low = state.material < d.batchSize / 2 && state.materialFactor <= autoBuyBelowFactor;
+    if (low || state.material < d.batchSize / 10) buyMaterial(state, ctx);
   }
 
   // Customers buy what they want, up to what is in stock.