Initial checkin of the new Mozart compositor.

mojo/services/gfx/composition/interfaces/compositor.mojom

+// 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/gpu/interfaces/context_provider.mojom";
+import "mojo/services/gfx/composition/interfaces/scene_token.mojom";
+import "mojo/services/gfx/composition/interfaces/scenes.mojom";
+import "mojo/services/gfx/composition/interfaces/renderers.mojom";
+
+// Maximum length for a scene or renderer label.
+const uint32 kLabelMaxLength = 32;
+
+// The compositor manages scenes and scene graph renderers.
+//
+// Applications create scenes to describe graphical content they would like
+// to render, including references to other scenes they would like to compose.
+//
+// The system creates a renderer to bind a scene graph to a particular display.
+//
+// Refer to |Scene| and |Renderer| for more information about these objects.
+[ServiceName="mojo::gfx::composition::Compositor"]
+interface Compositor {
+  // Creates a scene.
+  //
+  // The |scene| is used to supply content for the scene.  The scene pipe
+  // is private to the scene and should not be shared with anyone else.
+  //
+  // The |scene_token| is used as a transferable reference which can be passed
+  // to owners of other scenes to allow them to embed this scene as a
+  // resource.  The compositor itself does not describe how this interaction
+  // should take place, only that the token may eventually be used to
+  // construct a |SceneResource|.
+  //
+  // The |label| is an optional name to associate with the view for
+  // diagnostic purposes.  The label will be truncated if it is longer
+  // than |kLabelMaxLength|.
+  //
+  // To unregister the scene, simply close the |scene| message pipe.
+  CreateScene(Scene& scene, string? label) => (SceneToken scene_token);
+
+  // Creates a scene graph renderer.
+  //
+  // The |context_provider| provides the GL Context to which the content
+  // should be rendered.  This will typically be a display.
+  //
+  // The |label| is an optional name to associate with the renderer for
+  // diagnostic purposes.  The label will be truncated if it is longer
+  // than |kLabelMaxLength|.
+  //
+  // To destroy the renderer, simply close the |renderer| message pipe.
+  CreateRenderer(mojo.ContextProvider context_provider,
+                 Renderer& renderer, string? label);
+};