<!DOCTYPE html>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>
<script src="file:///gen/layout_test_data/mojo/public/js/mojo_bindings.js"></script>
<script src="file:///gen/device/vr/public/mojom/vr_service.mojom.js"></script>
<script src="../external/wpt/resources/chromium/webxr-test.js"></script>
<script src="../external/wpt/webxr/resources/webxr_test_constants.js"></script>
<script src="../xr/resources/xr-test-utils.js"></script>
<canvas id="webgl-canvas"></canvas>

<script>
const TEN_SECONDS = 10000; // 10k ms in ten seconds
const ONE_MINUTE = 60000; // 60k ms in one minute

let testName = "XRFrame getViewerPose updates on the next frame";

let fakeDeviceInitParams = { supportsImmersive:true };

let requestSessionModes = [
  'inline',
  'immersive-vr',
];

let testFunction = function(session, t, fakeDeviceController) {
  // Session must have a baseLayer or else frame requests will be ignored.
  session.updateRenderState({
    baseLayer: new XRWebGLLayer(session, gl, {
        compositionDisabled: session.mode == 'inline' })
  });

  // Need to have a valid pose or input event's don't process.
  fakeDeviceController.setXRPresentationFrameData(
  VALID_POSE_MATRIX, [{
    eye:"left",
    projectionMatrix: VALID_PROJECTION_MATRIX,
    viewMatrix: VALID_VIEW_MATRIX
  }, {
    eye:"right",
    projectionMatrix: VALID_PROJECTION_MATRIX,
    viewMatrix: VALID_VIEW_MATRIX
  }]);

  return session.requestReferenceSpace('local')
    .then((referenceSpace) => new Promise((resolve, reject) => {
      let counter = 0;
      let windowFrameTime = 0;
      let frameTime = 0;

      function onFrameFirst(time, xrFrame) {
        frameTime = time;
        let now = performance.now();

        t.step( () => {
          // This callback must be the first one called.
          assert_equals(counter, 0);

          // window.requestAnimationFrame and session.requestAnimationFrame
          // should be providing timestamps that are on the same scale and
          // within a resonable margin of error of eachother. This means that
          // this frame's timestamp should be larger than one provided to a
          // previous window.requestAnimationFrame and should also be within
          // a sane delta of it. One minute is probably overly generous here,
          // but it will at least catch cases where the times are reported with
          // entirely different bases.
          assert_greater_than(frameTime, windowFrameTime);
          assert_approx_equals(frameTime, windowFrameTime, ONE_MINUTE);

          // There's going to be some disparity between performance.now() and
          // the timestamp passed into the callback, but it shouldn't be huge.
          // If they're more than ten seconds apart something has gone horribly
          // wrong.
          assert_approx_equals(frameTime, now, TEN_SECONDS);
        });

        counter++;
      }

      function onFrameSubsequent(time, xrFrame) {
        t.step( () => {
          // The timestamp passed to this callback should be exactly equal to
          // the one passed to the first callback in this set.
          assert_equals(time, frameTime);
        });

        counter++;
      }

      function onFrameLast(time, xrFrame) {
        t.step( () => {
          // Make sure all the previous callbacks fired as expected.
          assert_equals(counter, 11);
        });

        // Finished.
        resolve();
      }

      window.requestAnimationFrame((time) => {
        windowFrameTime = time;

        // Queue up several callbacks
        session.requestAnimationFrame(onFrameFirst);
        for (let i = 0; i < 10; ++i) {
          session.requestAnimationFrame(onFrameSubsequent);
        }
        session.requestAnimationFrame(onFrameLast);
      });

    }));
};

xr_session_promise_test(
  testFunction, fakeDeviceInitParams, requestSessionModes, testName);

</script>