[Chromoting] Implement GlRenderer

remoting/client/gl_canvas.cc

 // 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.
 
 #include "remoting/client/gl_canvas.h"
 
 #include "base/logging.h"
 #include "remoting/client/gl_helpers.h"
 
 namespace {
@@ skipping 66 matching lines @@
   glDisable(GL_BLEND);
   glDisableVertexAttribArray(tex_cord_location_);
   glDisableVertexAttribArray(position_location_);
   glDeleteProgram(program_);
   glDeleteShader(vertex_shader_);
   glDeleteShader(fragment_shader_);
 }
 
 void GlCanvas::SetNormalizedTransformation(const std::array<float, 9>& matrix) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  glUniformMatrix3fv(transform_location_, 1, GL_TRUE, matrix.data());

[Yuwei, 2016/07/25 22:13:55]

There was a bug in GlCanvas.

It turns out the ES 2 spec (terrible spec :( ) says the |transpose| argument of
glUniformMatrix3fv must be set to GL_FALSE, which mean we need to manually
transpose the matrix before sending it to GPU.

This bug doesn't appear on my Nexus 6P since it automatically uses the ES 3
lib...

+  glUniformMatrix3fv(transform_location_, 1, GL_FALSE, matrix.data());
   transformation_set_ = true;
 }
 
 void GlCanvas::DrawTexture(int texture_id,
                            GLuint texture_handle,
                            GLuint vertex_buffer,
                            float alpha_multiplier) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (!transformation_set_) {
     return;
@@ skipping 12 matching lines @@
   glDrawArrays(GL_TRIANGLE_STRIP, 0, kVertexCount);
   glBindBuffer(GL_ARRAY_BUFFER, 0);
   glBindTexture(GL_TEXTURE_2D, 0);
 }
 
 int GlCanvas::GetGlVersion() const {
   return gl_version_;
 }
 
 }  // namespace remoting