fix: Changing prices and dynamics in revenus

public/js/engine/formulas.js

@@ -36,15 +36,19 @@ export function materialUnitPrice(mm, totalProduced) {
 }
 
 /**
- * What one purchase of material looks like. The lot grows with the operation
- * (a share of everything produced so far, or `batchSecondsOfProduction` of
- * current output), in doubling steps so the price stays readable.
- * `factor` is the market's current noise, `discount` comes from upgrades.
+ * What one purchase of material looks like.
+ *
+ * The lot covers `batchSecondsOfProduction` of current output (in doubling
+ * steps, never below `minBatch`), times `sizeMultiplier` from the "bigger
+ * stacks" upgrades. The price of a lot is proportional to its size: a bigger
+ * stack costs more in total, while the price PER UNIT keeps falling with scale
+ * (see materialUnitPrice). `factor` is the market's current noise and
+ * `discount` comes from upgrades. Cost is exact to the cent.
  */
-export function materialBatch(mm, totalProduced, rate, factor, discount) {
-  const basis = Math.max(totalProduced * mm.batchShareOfTotal, rate * mm.batchSecondsOfProduction);
+export function materialBatch(mm, totalProduced, rate, factor, discount, sizeMultiplier = 1) {
+  const basis = rate * mm.batchSecondsOfProduction;
   const doublings = Math.max(0, Math.floor(Math.log2(Math.max(1, basis / mm.minBatch))));
-  const size = mm.minBatch * 2 ** doublings;
+  const size = mm.minBatch * 2 ** doublings * sizeMultiplier;
   const cents = size * materialUnitPrice(mm, totalProduced) * factor * discount;
   return { size, cost: Math.max(0.01, Math.round(cents * 100) / 100) };
 }