Release Healer Man 0.1.9

src/scene/frameRateGovernor.test.ts

@@ -0,0 +1,64 @@
+import { describe, expect, it } from "vitest";
+import {
+  createFrameRateGovernor,
+  resetFrameRateGovernor,
+  stepFrameRateGovernor,
+} from "./frameRateGovernor";
+
+function renderCount(targetFps: 30 | 60, sourceFps: number, durationMs = 1_000): number {
+  let state = createFrameRateGovernor(targetFps);
+  let renders = 0;
+  for (let timestamp = 0; timestamp <= durationMs; timestamp += 1_000 / sourceFps) {
+    const step = stepFrameRateGovernor(state, timestamp);
+    state = step.state;
+    if (step.shouldRender) renders += 1;
+  }
+  return renders;
+}
+
+describe("frame-rate governor", () => {
+  it("holds capped modes near their target on high-refresh displays", () => {
+    expect(renderCount(30, 144)).toBeGreaterThanOrEqual(30);
+    expect(renderCount(30, 144)).toBeLessThanOrEqual(31);
+    expect(renderCount(60, 240)).toBeGreaterThanOrEqual(60);
+    expect(renderCount(60, 240)).toBeLessThanOrEqual(61);
+  });
+
+  it("renders every source callback in display mode", () => {
+    let state = createFrameRateGovernor("display", 4);
+    for (const timestamp of [1_000, 1_008, 1_016]) {
+      const step = stepFrameRateGovernor(state, timestamp);
+      state = step.state;
+      expect(step.shouldRender).toBe(true);
+    }
+    expect(state.elapsedSeconds).toBeCloseTo(4.016);
+  });
+
+  it("skips missed deadlines without emitting a catch-up burst", () => {
+    let state = createFrameRateGovernor(60);
+    state = stepFrameRateGovernor(state, 0).state;
+    const delayed = stepFrameRateGovernor(state, 100);
+    expect(delayed.shouldRender).toBe(true);
+    expect(delayed.state.nextDeadlineMs).toBeGreaterThan(100);
+    const sameTimestamp = stepFrameRateGovernor(delayed.state, 100);
+    expect(sameTimestamp.shouldRender).toBe(false);
+  });
+
+  it("preserves elapsed time while resetting the wall-clock baseline", () => {
+    let state = createFrameRateGovernor(30, 2);
+    state = stepFrameRateGovernor(state, 1_000).state;
+    state = stepFrameRateGovernor(state, 1_034).state;
+    const reset = resetFrameRateGovernor(state, 60);
+    const resumed = stepFrameRateGovernor(reset, 90_000);
+    expect(resumed.shouldRender).toBe(true);
+    expect(resumed.elapsedSeconds).toBeCloseTo(state.elapsedSeconds);
+  });
+
+  it("never moves elapsed time backwards", () => {
+    let state = createFrameRateGovernor(60);
+    state = stepFrameRateGovernor(state, 20).state;
+    state = stepFrameRateGovernor(state, 40).state;
+    const backwards = stepFrameRateGovernor(state, 10);
+    expect(backwards.elapsedSeconds).toBe(state.elapsedSeconds);
+  });
+});