--- title: VRDisplay.requestAnimationFrame() slug: Web/API/VRDisplay/requestAnimationFrame translation_of: Web/API/VRDisplay/requestAnimationFrame ---
{{APIRef("WebVR API")}}{{SeeCompatTable}}

Метод requestAnimationFrame() интерфейса {{domxref("VRDisplay")}} является специфичной реализацией метода {{domxref("Window.requestAnimationFrame")}} и принимает в качестве аргумента колбэк-функцию. Эта функция будет вызвана, когда объект типа VRDisplay будет готов отобразить новый кадр сцены:

Синтаксис

var handle = vrDisplayInstance.requestAnimationFrame(callback);

Параметры

callback
Колбэк-функция, которая будет вызвана когда объект типа VRDisplay будет готов отобразить новый кадр сцены.

Возвращаемое значение

A long representing the handle of the requestAnimationFrame() call. This can then be passed to a {{domxref("VRDisplay.cancelAnimationFrame()")}} call to unregister the callback.

Examples

var frameData = new VRFrameData();
var vrDisplay;

navigator.getVRDisplays().then(function(displays) {
  vrDisplay = displays[0];
  console.log('Display found');
  // Starting the presentation when the button is clicked: It can only be called in response to a user gesture
  btn.addEventListener('click', function() {
    vrDisplay.requestPresent([{ source: canvas }]).then(function() {
      drawVRScene();
    });
  });
});

// WebVR: Draw the scene for the WebVR display.
function drawVRScene() {
  // WebVR: Request the next frame of the animation
  vrSceneFrame = vrDisplay.requestAnimationFrame(drawVRScene);

  // Populate frameData with the data of the next frame to display
  vrDisplay.getFrameData(frameData);

  // You can get the position, orientation, etc. of the display from the current frame's pose
  var curFramePose = frameData.pose;
  var curPos = curFramePose.position;
  var curOrient = curFramePose.orientation;

  // Clear the canvas before we start drawing on it.

  gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

  // WebVR: Create the required projection and view matrix locations needed
  // for passing into the uniformMatrix4fv methods below

  var projectionMatrixLocation = gl.getUniformLocation(shaderProgram, "projMatrix");
  var viewMatrixLocation = gl.getUniformLocation(shaderProgram, "viewMatrix");

  // WebVR: Render the left eye’s view to the left half of the canvas
  gl.viewport(0, 0, canvas.width * 0.5, canvas.height);
  gl.uniformMatrix4fv(projectionMatrixLocation, false, frameData.leftProjectionMatrix);
  gl.uniformMatrix4fv(viewMatrixLocation, false, frameData.leftViewMatrix);
  drawGeometry();

  // WebVR: Render the right eye’s view to the right half of the canvas
  gl.viewport(canvas.width * 0.5, 0, canvas.width * 0.5, canvas.height);
  gl.uniformMatrix4fv(projectionMatrixLocation, false, frameData.rightProjectionMatrix);
  gl.uniformMatrix4fv(viewMatrixLocation, false, frameData.rightViewMatrix);
  drawGeometry();

  function drawGeometry() {
    // draw the view for each eye
  }

    ...

  // WebVR: Indicate that we are ready to present the rendered frame to the VR display
  vrDisplay.submitFrame();
}

Note: You can see this complete code at raw-webgl-example.

Specifications

Specification Status Comment
{{SpecName('WebVR 1.1', '#dom-vrdisplay-requestanimationframe', 'requestAnimationFrame()')}} {{Spec2('WebVR 1.1')}} Initial definition

Browser compatibility

{{Compat}}

See also