adrien
3e429ccb64
Production buildings are now independent private-sector agents: they keep what their output sells for, run only to the demand they can actually sell, and spend that cash on steel and high-tech upgrades when their demand grows. Grid power is a paid private flow between plants and their consumers, and regions synthesise the food their own harvest and the reachable market cannot supply. Island regions no longer famine: a region with no reachable supplier grows its whole shortfall from energy, and grid power now feeds cities and food before the converters, so a famine never waits on a factory. Bundles the in-progress tree cleanup that was already present in the working tree.
122 lines
4.6 KiB
JavaScript
122 lines
4.6 KiB
JavaScript
import { TestCase } from "./framework/test_case.js";
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import { smallState, cityOf } from "./framework/helpers.js";
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import { key } from "../shared/hex.js";
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import { RESOURCE_RULES } from "../shared/data.js";
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import {
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foodNeedPerDay,
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tileFoodOutput,
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foodSynthesisEnergy,
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foodSynthesisMarginalEnergy,
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synthesisedFoodFor,
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} from "../shared/resources.js";
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const Q = RESOURCE_RULES.foodSynthesisQuadratic;
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// The land's daily harvest in one region, exactly as the daily tick sums it.
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function regionFood(state, city) {
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let total = 0;
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for (const coords of state.regionTiles(city)) {
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const k = key(coords.x, coords.y);
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if ((state.tilePopulation.get(k) || 0) <= 0) continue;
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total += tileFoodOutput(state.tiles[k]) * state._regionFoodMultiplier(city);
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}
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return total;
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}
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export class FoodSynthesisMathTest extends TestCase {
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test_energy_for_extra_food_is_quadratic() {
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this.assertApprox(foodSynthesisEnergy(0), 0);
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this.assertApprox(foodSynthesisEnergy(10), Q * 100);
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this.assertApprox(foodSynthesisEnergy(20), 4 * foodSynthesisEnergy(10));
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}
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test_the_marginal_tonne_costs_more_than_the_last() {
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this.assertApprox(foodSynthesisMarginalEnergy(0), 0);
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this.assertApprox(foodSynthesisMarginalEnergy(10), 2 * Q * 10);
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this.assertGreater(
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foodSynthesisMarginalEnergy(20), foodSynthesisMarginalEnergy(10),
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"diminishing returns: the next tonne costs more"
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);
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}
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test_a_region_grows_until_energy_meets_the_market_price() {
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const foodPrice = 5100;
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const energyPrice = 0.051;
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const breakEven = foodPrice / (2 * Q * energyPrice);
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this.assertApprox(synthesisedFoodFor(foodPrice, energyPrice, 1e6), breakEven);
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// A shortfall smaller than the break-even caps the extra food.
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this.assertApprox(synthesisedFoodFor(foodPrice, energyPrice, 10), 10);
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// Cheap energy grows past a larger shortfall; dear energy grows almost none.
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this.assertGreater(synthesisedFoodFor(foodPrice, 0.0001, 1e6), breakEven);
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this.assertApprox(
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synthesisedFoodFor(foodPrice, 1000, 1e6), foodPrice / (2 * Q * 1000)
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);
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this.assertApprox(synthesisedFoodFor(foodPrice, 1e9, 1e6), foodPrice / (2 * Q * 1e9));
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}
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test_no_synthesis_without_a_price_or_a_shortfall() {
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this.assertApprox(synthesisedFoodFor(5100, 0, 1000), 0);
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this.assertApprox(synthesisedFoodFor(0, 0.05, 1000), 0);
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this.assertApprox(synthesisedFoodFor(5100, 0.05, 0), 0);
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this.assertApprox(synthesisedFoodFor(5100, 0.05, -10), 0);
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}
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test_the_region_grows_whatever_the_market_cannot_supply() {
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const foodPrice = 5100;
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const energyPrice = 0.051;
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const shortfall = 10_000;
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const breakEven = foodPrice / (2 * Q * energyPrice);
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// No reachable supplier: grow the whole shortfall.
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this.assertApprox(synthesisedFoodFor(foodPrice, energyPrice, shortfall, 0), shortfall);
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// A market that covers only part: grow the rest beyond the break-even.
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this.assertApprox(
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synthesisedFoodFor(foodPrice, energyPrice, shortfall, 4000),
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shortfall - 4000
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);
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// A market that covers the affordable portion: grow only the break-even.
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this.assertApprox(
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synthesisedFoodFor(foodPrice, energyPrice, shortfall, 9000),
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breakEven
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);
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this.assertGreater(breakEven, 0);
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}
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}
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export class FoodSynthesisModelTest extends TestCase {
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test_a_region_short_of_food_forces_extra_from_energy() {
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const state = smallState();
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const city = cityOf(state, 0);
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const shortfall = foodNeedPerDay(state.getCityEconomy(city).population) -
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regionFood(state, city);
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this.assertGreater(shortfall, 0, "the fixture region opens short of food");
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// Cheap energy against a dear market: force as much as the shortfall allows.
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state.setResourcePrice("energy", 0.00001);
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state.setResourcePrice("food", 1e9);
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state._tickResources();
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const extra = state._foodSynthesis.get(city.id) || 0;
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this.assertApprox(extra, shortfall, 1, "the whole shortfall is grown");
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}
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test_a_region_buys_instead_when_energy_is_dearer_than_food() {
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const state = smallState();
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const city = cityOf(state, 0);
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state.setResourcePrice("energy", 1e9);
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state.setResourcePrice("food", 1);
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state._tickResources();
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this.assertApprox(state._foodSynthesis.get(city.id) || 0, 0);
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}
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test_the_extra_food_lands_in_the_region_s_store() {
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const state = smallState();
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const city = cityOf(state, 0);
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state.setResourcePrice("energy", 0.00001);
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state.setResourcePrice("food", 1e9);
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state._tickResources();
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const produced = state.getCivResourceSummary(0).production.food;
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this.assertGreater(
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produced, regionFood(state, city),
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"the nation's food production includes the forced extra"
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);
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}
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}
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