Adding drawable to CRD andorid and iOS gl rendering pipeline.

remoting/client/display/canvas.h

Index: remoting/client/display/canvas.h
diff --git a/remoting/client/display/gl_canvas.h b/remoting/client/display/canvas.h
similarity index 59%
copy from remoting/client/display/gl_canvas.h
copy to remoting/client/display/canvas.h
index 975d79bc9f981b0b691fa91ca846b11b877be416..f83b464f94b3cd1a0fa11c930658fa9fc6f38440 100644
--- a/remoting/client/display/gl_canvas.h
+++ b/remoting/client/display/canvas.h
@@ -2,8 +2,8 @@
 // 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>
 
@@ -15,14 +15,14 @@ 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(){};

[joedow, 2017/01/10 00:19:43]

please run clang format to fix some spacing nits (i.e. space between () and {})

[nicholss, 2017/01/10 16:58:34]

It does not work on mac.

[joedow, 2017/01/10 18:49:27]

Weird, ok then add a space manually between parens and curly braces.

Is there an infrastructure bug open to get git cl format (clang format) working
for mac?

[Sergey Ulanov, 2017/01/10 23:07:18]

I'm pretty sure 'git cl format' should work on mac. Scott, what's the result you
get when running 'git cl format'. In this case you don't need ';' at the end.
Same for the destructor. Otherwise clang-format doesn't format it correctly.

 
-  ~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.
@@ -37,10 +37,10 @@ class GlCanvas {
   // 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.
@@ -52,43 +52,21 @@ class GlCanvas {
   // 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.

[joedow, 2017/01/10 00:19:43]

I could see this returning the OpenGL version for that impl but what does
version mean for other impls?  The caller would necessarily know what
implementation they are calling into so how would Version be used in an
impl-agnostic fashion?

[nicholss, 2017/01/10 16:58:34]

It is up to the impl. It is not a real concern here because we just have OpenGL
but I am attempting to remove the GL references from the interface. So I guess
it is TBD when that bridge needs crossing.

[joedow, 2017/01/10 18:49:27]

This still seem confusing to have on an interface for the canvas.  Can you
update the comment so you are explicit about what Version is used for?  I'm
trying to think of how this interface would be used and it isn't apparent what
Version means just by looking at the interface documentation.

[Yuwei, 2017/01/10 19:36:10]

GetGlVersion is only used by GlRenderLayer to decide whether ES3 optimization
should be applied. GlRenderLayer seems to be an implementation detail of
GlCanvas so alternatively you can have a CreateRenderLayer() function and return
a constructed object with the right version set up. Doesn't need to do it in
this CL though.

+  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;
-
- 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_;
+  virtual int GetMaxTextureSize() const = 0;
 
-  DISALLOW_COPY_AND_ASSIGN(GlCanvas);
+  DISALLOW_COPY_AND_ASSIGN(Canvas);

[joedow, 2017/01/10 00:19:43]

Add 'private:' above this line.  It was removed in the code deletion.

[nicholss, 2017/01/10 21:43:10]

Done.

 };
 
 }  // namespace remoting
 
-#endif  // REMOTING_CLIENT_DISPLAY_GL_CANVAS_H_
+#endif  // REMOTING_CLIENT_DISPLAY_CANVAS_H_