Adding drawable to CRD andorid and iOS gl rendering pipeline.

remoting/client/display/canvas.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_DISPLAY_GL_CANVAS_H_
-#define REMOTING_CLIENT_DISPLAY_GL_CANVAS_H_
+#ifndef REMOTING_CLIENT_DISPLAY_CANVAS_H_
+#define REMOTING_CLIENT_DISPLAY_CANVAS_H_
 
 #include <array>
 
 #include "base/macros.h"
-#include "base/threading/thread_checker.h"
 #include "remoting/client/display/sys_opengl.h"
 
 namespace remoting {
 
 // This class holds zoom and pan configurations of the canvas and is used to
 // draw textures on the canvas.
-// Must be constructed after the OpenGL surface is created and destroyed before
-// the surface is destroyed.
-class GlCanvas {
+class Canvas {
  public:
-  // gl_version: version number of the OpenGL ES context. Either 2 or 3.
-  GlCanvas(int gl_version);
+  Canvas(){};
 
-  ~GlCanvas();
+  virtual ~Canvas(){};
+
+  // Clears the frame.
+  virtual void Clear() = 0;
 
   // Sets the transformation matrix. This matrix defines how the canvas should
   // be shown on the view.
   // 3 by 3 transformation matrix, [ m0, m1, m2, m3, m4, m5, m6, m7, m8 ].
   // The matrix will be multiplied with the positions (with projective space,
   // (x, y, 1)) to draw the textures with the right zoom and pan configuration.
   //
   // | m0, m1, m2, |   | x |
   // | m3, m4, m5, | * | y |
   // | m6, m7, m8  |   | 1 |
   //
   // For a typical transformation matrix such that m1=m3=m6=m7=0 and m8=1, m0
   // and m4 defines the scaling factor of the canvas and m2 and m5 defines the
   // offset of the upper-left corner in pixel.
-  void SetTransformationMatrix(const std::array<float, 9>& matrix);
+  virtual void SetTransformationMatrix(const std::array<float, 9>& matrix) = 0;
 
   // Sets the size of the view in pixels.
-  void SetViewSize(int width, int height);
+  virtual void SetViewSize(int width, int height) = 0;
 
   // Draws the texture on the canvas. Nothing will happen if
   // SetNormalizedTransformation() has not been called.
   // vertex_buffer: reference to the 2x4x2 float vertex buffer.
   //                [ four (x, y) position of the texture vertices in pixel
   //                              with respect to the canvas,
   //                  four (x, y) position of the vertices in percentage
   //                              defining the visible area of the texture ]
   // alpha_multiplier: Will be multiplied with the alpha channel of the texture.
   //                   Passing 1 means no change of the transparency of the
   //                   texture.
-  void DrawTexture(int texture_id,
-                   GLuint texture_handle,
-                   GLuint vertex_buffer,
-                   float alpha_multiplier);
+  virtual void DrawTexture(int texture_id,
+                           GLuint texture_handle,
+                           GLuint vertex_buffer,
+                           float alpha_multiplier) = 0;
 
-  // Returns the version number of current OpenGL ES context. Either 2 or 3.
-  int GetGlVersion() const;
+  // Version if applicable to implementation.
+  virtual int GetVersion() const = 0;
 
   // Returns the maximum texture resolution limitation. Neither the width nor
   // the height of the texture can exceed this limitation.
-  int GetMaxTextureSize() const;
+  virtual int GetMaxTextureSize() const = 0;
 
- private:
-  int gl_version_;
-
-  int max_texture_size_ = 0;
-  bool transformation_set_ = false;
-  bool view_size_set_ = false;
-
-  // Handles.
-  GLuint vertex_shader_;
-  GLuint fragment_shader_;
-  GLuint program_;
-
-  // Locations of the corresponding shader attributes.
-  GLuint transform_location_;
-  GLuint view_size_location_;
-  GLuint texture_location_;
-  GLuint alpha_multiplier_location_;
-  GLuint position_location_;
-  GLuint tex_cord_location_;
-
-  base::ThreadChecker thread_checker_;
-
-  DISALLOW_COPY_AND_ASSIGN(GlCanvas);
+  DISALLOW_COPY_AND_ASSIGN(Canvas);
 };
 
 }  // namespace remoting
 
-#endif  // REMOTING_CLIENT_DISPLAY_GL_CANVAS_H_
+#endif  // REMOTING_CLIENT_DISPLAY_CANVAS_H_