[Chromoting] Implement GlRenderer

remoting/client/gl_renderer.h

+// Copyright 2016 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 REMOTING_CLIENT_GL_RENDERER_H_
+#define REMOTING_CLIENT_GL_RENDERER_H_
+
+#include <queue>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "remoting/client/gl_cursor.h"
+#include "remoting/client/gl_cursor_feedback.h"
+#include "remoting/client/gl_desktop.h"
+#include "remoting/proto/control.pb.h"
+
+namespace webrtc {
+class DesktopFrame;
+}  // namespace webrtc
+
+namespace remoting {
+
+namespace protocol {
+class CursorShapeInfo;
+}  // namespace protocol
+
+class GlCanvas;
+class GlRendererDelegate;
+
+// Renders desktop and cursor on the OpenGL surface. Can be created on any
+// thread but thereafter must be used and deleted on the same thread (usually
+// the display thread. Or any Chromium thread with a task runner attached to
+// it) unless otherwise noted.
+// The unit of all length arguments is pixel.
+class GlRenderer {
+ public:
+  explicit GlRenderer();
+  ~GlRenderer();
+
+  // The delegate can be set on any hread no more than once before calling any
+  // On* functions.
+  void SetDelegate(base::WeakPtr<GlRendererDelegate> delegate);
+
+  // Notifies the delegate with the current canvas size. Canvas size will be
+  // (0, 0) if no desktop frame is received yet.
+  // Caller can use this function to get the canvas size when the surface is
+  // recreated.
+  void RequestCanvasSize();
+
+  // Sets the pixel based transformation matrix related to the size of the
+  // canvas.
+  // 3 by 3 transformation matrix, [ m0, m1, m2, m3, m4, m5, m6, m7, m8 ].
+  //
+  // | m0, m1, m2, |   | x |
+  // | m3, m4, m5, | * | y |
+  // | m6, m7, m8  |   | 1 |
+  //
+  // The final size of the canvas will be (m0*canvas_width, m4*canvas_height)
+  // and the top-left corner will be (m2, m5) in pixel coordinates.
+  void OnPixelTransformationChanged(const std::array<float, 9>& matrix);
+
+  void OnCursorMoved(int x, int y);
+
+  void OnCursorInputFeedback(int x, int y, float diameter);
+
+  void OnCursorVisibilityChanged(bool visible);
+
+  // Called when a desktop frame is received.
+  // The size of the canvas is determined by the dimension of the desktop frame.
+  // |done| will be queued up and called on the display thread after the actual
+  // rendering happens.
+  void OnFrameReceived(std::unique_ptr<webrtc::DesktopFrame> frame,
+                       const base::Closure& done);
+
+  void OnCursorShapeChanged(const protocol::CursorShapeInfo& shape);
+
+  // Called after the EGL/EAGL context is established and the surface is created
+  // (or recreated). Previous desktop frame and canvas transformation will be
+  // lost after calling this function.
+  // Caller must call OnSurfaceDestroyed() before calling this function if the
+  // surface is recreated.
+  void OnSurfaceCreated(int gl_version);
+
+  // Sets the size of the view. Called right after OnSurfaceCreated() or
+  // whenever the view size is changed.
+  void OnSurfaceChanged(int view_width, int view_height);
+
+  // Called when the surface is destroyed.
+  void OnSurfaceDestroyed();
+
+  // Returns the weak pointer to be used on the display thread.
+  base::WeakPtr<GlRenderer> GetWeakPtr();
+
+ private:
+  // Post a rendering task to the task runner of current thread.
+  // Do nothing if render_callback_ is not set yet or an existing rendering task
+  // in the queue will cover changes before this function is called.
+  void RequestRender();
+
+  // Draws out everything on current OpenGL buffer and runs closures in
+  // |pending_done_callbacks_|.
+  // Nothing will be drawn nor the done callbacks will be run if |delegate_| is
+  // invalid or !delegate_.CanRenderFrame().
+  void OnRender();
+
+  base::WeakPtr<GlRendererDelegate> delegate_;
+
+  // Done callbacks from OnFrameReceived. Will all be called once rendering
+  // takes place.
+  std::queue<base::Closure> pending_done_callbacks_;
+
+  bool render_scheduled_ = false;
+
+  int view_width_ = 0;
+  int view_height_ = 0;
+  int canvas_width_ = 0;
+  int canvas_height_ = 0;
+
+  std::unique_ptr<GlCanvas> canvas_;
+
+  GlCursor cursor_;
+  GlCursorFeedback cursor_feedback_;
+  GlDesktop desktop_;
+
+  base::ThreadChecker thread_checker_;
+  base::WeakPtr<GlRenderer> weak_ptr_;
+  base::WeakPtrFactory<GlRenderer> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GlRenderer);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_CLIENT_GL_RENDERER_H_