// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

[DartPackage="mojo_services"]
module mojo.gfx.composition;

import "mojo/services/geometry/interfaces/geometry.mojom";
import "mojo/services/gfx/composition/interfaces/hit_tests.mojom";
import "mojo/services/gfx/composition/interfaces/scene_token.mojom";
import "mojo/services/gfx/composition/interfaces/scheduling.mojom";

// The renderer is a service which renders a scene graph to a display.
//
// Use |Compositor.CreateRenderer()| to create a renderer.
interface Renderer {
  // Sets the scene to be displayed by the renderer.
  //
  // The |size| specifies the size of the output.
  //
  // The |scene_token| specifies the scene which will be drawn as the
  // root of the scene graph.
  //
  // The |scene_version| specifies the version of the scene to render,
  // Use |kSceneVersionNone| to request the most recently published
  // version of the scene if synchronization is unimportant.
  //
  // The |viewport| specifies the portion of the scene to render in pixels.
  //
  // It is an error to create a renderer with an invalid |scene_token|
  // or |size|; the connection will be closed.
  // TODO: make this an event instead
  SetRootScene(SceneToken scene_token,
               uint32 scene_version,
               mojo.Rect viewport);

  // Dissociates the root scene from the renderer.
  ClearRootScene();

  // Gets a scheduler to receive frame timing information for the renderer.
  GetScheduler(FrameScheduler& scheduler);

  // Provides an interface which can be used to perform hit tests on the
  // contents of the renderer's scene graph.
  GetHitTester(HitTester& hit_tester);
};