Add a SpinningCube to Mojo's sample_app

mojo/examples/sample_app/spinning_cube.h

+// Copyright 2013 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.
+
+#ifndef MOJO_EXAMPLES_SAMPLE_APP_SPINNING_CUBE_H_
+#define MOJO_EXAMPLES_SAMPLE_APP_SPINNING_CUBE_H_
+
+#include "base/memory/scoped_ptr.h"
+
+namespace gpu {
+namespace gles2 {
+class GLES2Interface;
+}
+}
+
+namespace mojo {
+namespace examples {
+
+class SpinningCube {
+ public:
+  explicit SpinningCube(gpu::gles2::GLES2Interface* gl,
+                        int width,
+                        int height);
+  virtual ~SpinningCube();
+
+  void Update(float delta_time);
+  void Draw();

[jamesr, 2013/11/06 01:42:45]

what do you expect will call these functions?

[abarth-chromium, 2013/11/06 02:25:10]

Probably something in sample_app.cc.  Once we have a Graphics3DClient interface,
the sample_app can listen for OnSwapBuffersComplete and draw a new frame.

+
+ private:
+  class GLState;
+
+  void Initialize();
+
+  gpu::gles2::GLES2Interface* gl_;

[jamesr, 2013/11/06 01:42:45]

does this have some sort of ownership stake in the context?

[abarth-chromium, 2013/11/06 02:25:10]

We're probably going to end up calling static C functions to talk to GL, so this
pointer will go away.  We'll probably need to split this object into two pieces:
one that survives the destruction of the context and one that has the
context-specific state.

+  int width_;
+  int height_;
+
+  scoped_ptr<GLState> state_;
+};
+
+}  // namespace examples
+}  // namespace mojo
+
+#endif  // MOJO_EXAMPLES_SAMPLE_APP_SPINNING_CUBE_H_