Attach YUV420 to RGB converter to GLContext

ui/gl/yuv_to_rgb_converter.cc

Index: ui/gl/yuv_to_rgb_converter.cc
diff --git a/ui/gl/yuv_to_rgb_converter.cc b/ui/gl/yuv_to_rgb_converter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4c19b3685d0ceb1396c3c49b0f5b067f2bf26571
--- /dev/null
+++ b/ui/gl/yuv_to_rgb_converter.cc
@@ -0,0 +1,166 @@
+// 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 "ui/gl/yuv_to_rgb_converter.h"
+
+#include "base/strings/stringize_macros.h"
+#include "base/strings/stringprintf.h"
+#include "ui/gl/gl_helper.h"
+#include "ui/gl/gl_implementation.h"
+#include "ui/gl/scoped_api.h"
+#include "ui/gl/scoped_binders.h"
+
+namespace gl {
+namespace {
+
+const char kVertexHeaderCompatiblityProfile[] =
+    "#version 110\n"
+    "#define ATTRIBUTE attribute\n"
+    "#define VARYING varying\n";
+
+const char kVertexHeaderCoreProfile[] =
+    "#version 150\n"
+    "#define ATTRIBUTE in\n"
+    "#define VARYING out\n";
+
+const char kFragmentHeaderCompatiblityProfile[] =
+    "#version 110\n"
+    "#extension GL_ARB_texture_rectangle : require\n"
+    "#define VARYING varying\n"
+    "#define FRAGCOLOR gl_FragColor\n"
+    "#define TEX texture2DRect\n";
+
+const char kFragmentHeaderCoreProfile[] =
+    "#version 150\n"
+    "#define VARYING in\n"
+    "#define TEX texture\n"
+    "#define FRAGCOLOR frag_color\n"
+    "out vec4 FRAGCOLOR;\n";
+
+// clang-format off
+const char kVertexShader[] =
+STRINGIZE(
+  ATTRIBUTE vec2 a_position;
+  uniform vec2 a_texScale;
+  VARYING vec2 v_texCoord;
+  void main() {
+    gl_Position = vec4(a_position.x, a_position.y, 0.0, 1.0);
+    v_texCoord = (a_position + vec2(1.0, 1.0)) * 0.5 * a_texScale;
+  }
+);
+
+const char kFragmentShader[] =
+STRINGIZE(
+  uniform sampler2DRect a_y_texture;
+  uniform sampler2DRect a_uv_texture;
+  VARYING vec2 v_texCoord;
+  void main() {
+    vec3 yuv_adj = vec3(-0.0625, -0.5, -0.5);
+    mat3 yuv_matrix = mat3(vec3(1.164, 1.164, 1.164),
+                           vec3(0.0, -.391, 2.018),
+                           vec3(1.596, -.813, 0.0));
+    vec3 yuv = vec3(
+        TEX(a_y_texture, v_texCoord).r,
+        TEX(a_uv_texture, v_texCoord * 0.5).rg);
+    FRAGCOLOR = vec4(yuv_matrix * (yuv + yuv_adj), 1.0);
+  }
+);
+// clang-format on
+
+}  // namespace
+
+YUVToRGBConverter::YUVToRGBConverter() {
+  bool use_core_profile =
+      gfx::GetGLImplementation() == gfx::kGLImplementationDesktopGLCoreProfile;
+  gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
+  glGenFramebuffersEXT(1, &framebuffer_);
+  vertex_buffer_ = gfx::GLHelper::SetupQuadVertexBuffer();
+  vertex_shader_ = gfx::GLHelper::LoadShader(
+      GL_VERTEX_SHADER,
+      base::StringPrintf("%s\n%s",
+                         use_core_profile ? kVertexHeaderCoreProfile
+                                          : kVertexHeaderCompatiblityProfile,
+                         kVertexShader)
+          .c_str());
+  fragment_shader_ = gfx::GLHelper::LoadShader(
+      GL_FRAGMENT_SHADER,
+      base::StringPrintf("%s\n%s",
+                         use_core_profile ? kFragmentHeaderCoreProfile
+                                          : kFragmentHeaderCompatiblityProfile,
+                         kFragmentShader)
+          .c_str());
+  program_ = gfx::GLHelper::SetupProgram(vertex_shader_, fragment_shader_);
+
+  gfx::ScopedUseProgram use_program(program_);
+  size_location_ = glGetUniformLocation(program_, "a_texScale");
+  DCHECK_NE(-1, size_location_);
+  int y_sampler_location = glGetUniformLocation(program_, "a_y_texture");
+  DCHECK_NE(-1, y_sampler_location);
+  int uv_sampler_location = glGetUniformLocation(program_, "a_uv_texture");
+  DCHECK_NE(-1, uv_sampler_location);
+
+  glUniform1i(y_sampler_location, 0);
+  glUniform1i(uv_sampler_location, 1);
+}
+
+YUVToRGBConverter::~YUVToRGBConverter() {
+  gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
+  glDeleteProgram(program_);
+  glDeleteShader(vertex_shader_);
+  glDeleteShader(fragment_shader_);
+  glDeleteBuffersARB(1, &vertex_buffer_);
+  glDeleteFramebuffersEXT(1, &framebuffer_);
+}
+
+void YUVToRGBConverter::CopyYUV420ToRGB(unsigned target,
+                                        unsigned y_texture,
+                                        unsigned uv_texture,
+                                        const gfx::Size& size,
+                                        unsigned rgb_texture) {
+  // Only support for rectangle targets exists so far.
+  DCHECK_EQ(static_cast<GLenum>(GL_TEXTURE_RECTANGLE_ARB), target);
+  gfx::ScopedSetGLToRealGLApi scoped_set_gl_api;
+
+  // Note that state restoration is done explicitly instead of scoped binders to
+  // avoid https://crbug.com/601729.
+  GLint old_active_texture = -1;
+  glGetIntegerv(GL_ACTIVE_TEXTURE, &old_active_texture);
+  GLint old_texture0_binding = -1;
+  glActiveTexture(GL_TEXTURE0);
+  glGetIntegerv(GL_TEXTURE_BINDING_RECTANGLE_ARB, &old_texture0_binding);
+  GLint old_texture1_binding = -1;
+  glActiveTexture(GL_TEXTURE1);
+  glGetIntegerv(GL_TEXTURE_BINDING_RECTANGLE_ARB, &old_texture1_binding);
+
+  // Allocate the rgb texture.
+  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, rgb_texture);
+  glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGB, size.width(), size.height(),
+               0, GL_RGB, GL_UNSIGNED_BYTE, nullptr);
+
+  // Set up and issue the draw call.
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, y_texture);
+  glActiveTexture(GL_TEXTURE1);
+  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, uv_texture);
+  gfx::ScopedFrameBufferBinder framebuffer_binder(framebuffer_);
+  gfx::ScopedViewport viewport(0, 0, size.width(), size.height());
+  glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                            GL_TEXTURE_RECTANGLE_ARB, rgb_texture, 0);
+  DCHECK_EQ(static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE),
+            glCheckFramebufferStatusEXT(GL_FRAMEBUFFER));
+  gfx::ScopedUseProgram use_program(program_);
+  glUniform2f(size_location_, size.width(), size.height());
+  gfx::GLHelper::DrawQuad(vertex_buffer_);
+
+  // Restore previous state.
+  glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                            GL_TEXTURE_RECTANGLE_ARB, 0, 0);
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, old_texture0_binding);
+  glActiveTexture(GL_TEXTURE1);
+  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, old_texture1_binding);
+  glActiveTexture(old_active_texture);
+}
+
+}  // namespace gl