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src/game-loop/agent-population.test.ts

@@ -0,0 +1,86 @@
+import { vec2 } from 'gl-matrix';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+vi.hoisted(() => {
+  Object.defineProperty(globalThis, 'localStorage', {
+    configurable: true,
+    value: {
+      getItem: vi.fn(() => null),
+      setItem: vi.fn(),
+    },
+  });
+});
+
+import { appConfig } from '../config';
+import { AgentGenerationPipeline } from '../pipelines/agents/agent-generation/agent-generation-pipeline';
+import { settings } from '../settings';
+import { AgentPopulation } from './agent-population';
+
+const originalAgentBudgetMax = settings.agentBudgetMax;
+const originalBrushSize = settings.brushSize;
+const originalSelectedColorIndex = settings.selectedColorIndex;
+const originalSpawnPerPixel = settings.spawnPerPixel;
+
+const createPopulation = () => {
+  const pipeline = {
+    maxAgentCount: 10_000_000,
+    writeAgents: vi.fn(),
+    resizeAgents: vi.fn(),
+    compactAgents: vi.fn(),
+  } as unknown as AgentGenerationPipeline;
+
+  return new AgentPopulation(pipeline);
+};
+
+const setPopulationCounts = (
+  population: AgentPopulation,
+  activeCount: number,
+  targetBudget: number
+) => {
+  Object.assign(population as unknown as Record<string, number>, {
+    activeCount,
+    targetBudget,
+  });
+};
+
+describe('AgentPopulation adaptive budget', () => {
+  beforeEach(() => {
+    settings.agentBudgetMax = 1_000_000;
+    settings.brushSize = 1;
+    settings.selectedColorIndex = 0;
+    settings.spawnPerPixel = 1;
+  });
+
+  afterEach(() => {
+    settings.agentBudgetMax = originalAgentBudgetMax;
+    settings.brushSize = originalBrushSize;
+    settings.selectedColorIndex = originalSelectedColorIndex;
+    settings.spawnPerPixel = originalSpawnPerPixel;
+  });
+
+  it('expands beyond the 1M start cap only when new agents arrive under healthy FPS', () => {
+    const population = createPopulation();
+    setPopulationCounts(population, 1_000_000, 1_000_000);
+
+    population.growBudget(1 / 60, 60, 60);
+    population.spawnStrokeAgents(vec2.fromValues(0, 0), vec2.fromValues(16, 0));
+
+    expect(settings.agentBudgetMax).toBeGreaterThan(1_000_000);
+    expect(population.activeAgentCount).toBeGreaterThan(1_000_000);
+    expect(settings.agentBudgetMax).toBeLessThanOrEqual(
+      appConfig.simulation.globalAgentCap
+    );
+  });
+
+  it('decreases the cap and active count slowly when FPS falls below the threshold', () => {
+    const population = createPopulation();
+    setPopulationCounts(population, 1_000_000, 1_000_000);
+
+    population.growBudget(10, 50, 60);
+
+    expect(settings.agentBudgetMax).toBe(appConfig.simulation.budget.adaptiveCapMin);
+    expect(population.activeAgentCount).toBe(
+      appConfig.simulation.budget.adaptiveCapMin
+    );
+  });
+});