gpu: Add YCbCr 420v extension.

ui/gl/gl_helper.cc

Index: ui/gl/gl_helper.cc
diff --git a/ui/gl/gl_helper.cc b/ui/gl/gl_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..edf5f53afbaeb4188b03c733c3727c4071bcdf6e
--- /dev/null
+++ b/ui/gl/gl_helper.cc
@@ -0,0 +1,73 @@
+// Copyright 2015 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 "ui/gl/gl_helper.h"
+
+#include <fstream>

[reveman, 2015/10/27 19:31:54]

fstream? what is this for?

[Daniele Castagna, 2015/10/29 20:09:04]

Leftover since I had a function to save the output to png. Removed.

+#include <string>
+
+#include "base/memory/scoped_ptr.h"

[reveman, 2015/10/27 19:31:54]

why this include? not seeing any use of scoped_ptr here

[Daniele Castagna, 2015/10/29 20:09:04]

Leftover.

+#include "ui/gfx/geometry/size.h"

[reveman, 2015/10/27 19:31:54]

this doesn't seem to be used either but it looks like a base/logging.h include
is missing 

[Daniele Castagna, 2015/10/29 20:09:04]

Removed size.h and added base/logging.h

+
+namespace gfx {
+
+// static
+GLuint GLHelper::CompileShader(GLenum type, const char* src) {
+  GLuint shader = glCreateShader(type);
+  // Load the shader source.
+  glShaderSource(shader, 1, &src, nullptr);
+  // Compile the shader.
+  glCompileShader(shader);
+  return shader;
+}
+
+// static
+GLuint GLHelper::LoadShader(GLenum type, const char* src) {
+  GLuint shader = CompileShader(type, src);
+
+  // Check the compile status.
+  GLint value = 0;
+  glGetShaderiv(shader, GL_COMPILE_STATUS, &value);
+  if (!value) {
+    char buffer[1024];
+    GLsizei length = 0;
+    glGetShaderInfoLog(shader, sizeof(buffer), &length, buffer);
+    std::string log(buffer, length);
+    DCHECK_EQ(1, value) << "Error compiling shader: " << log;
+    glDeleteShader(shader);
+    shader = 0;
+  }
+  return shader;
+}
+
+// static
+GLuint GLHelper::LinkProgram(GLuint vertex_shader, GLuint fragment_shader) {
+  // Create the program object.
+  GLuint program = glCreateProgram();
+  glAttachShader(program, vertex_shader);
+  glAttachShader(program, fragment_shader);
+  // Link the program.
+  glLinkProgram(program);
+  return program;
+}
+
+// static
+GLuint GLHelper::SetupProgram(GLuint vertex_shader, GLuint fragment_shader) {
+  GLuint program = LinkProgram(vertex_shader, fragment_shader);
+  // Check the link status.
+  GLint linked = 0;
+  glGetProgramiv(program, GL_LINK_STATUS, &linked);
+  if (!linked) {
+    char buffer[1024];
+    GLsizei length = 0;
+    glGetProgramInfoLog(program, sizeof(buffer), &length, buffer);
+    std::string log(buffer, length);
+    DCHECK_EQ(1, linked) << "Error linking program: " << log;
+    glDeleteProgram(program);
+    program = 0;
+  }
+  return program;
+}
+
+}  // namespace gfx