content/renderer/gpu/compositor_software_output_device_gl_adapter.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/renderer/gpu/compositor_software_output_device_gl_adapter.h"
   6
   7 #include "base/debug/trace_event.h"
   8 #include "base/logging.h"
   9 #include "third_party/skia/include/core/SkBitmap.h"
  10 #include "third_party/skia/include/core/SkPixelRef.h"
  11 #include "third_party/skia/include/core/SkDevice.h"
  12 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
  13 #include "third_party/WebKit/Source/Platform/chromium/public/WebSize.h"
  14
  15 #include <GLES2/gl2.h>
  16
  17 using WebKit::WebImage;
  18 using WebKit::WebGraphicsContext3D;
  19 using WebKit::WebSize;
  20
  21 namespace content {
  22
  23 //------------------------------------------------------------------------------
  24
  25 CompositorSoftwareOutputDeviceGLAdapter::
  26     CompositorSoftwareOutputDeviceGLAdapter(WebGraphicsContext3D* context3D)
  27     : initialized_(false),
  28       program_(0),
  29       vertex_shader_(0),
  30       fragment_shader_(0),
  31       vertex_buffer_(0),
  32       framebuffer_texture_id_(0),
  33       context3d_(context3D),
  34       locked_for_write_(false) {
  35 }
  36
  37 CompositorSoftwareOutputDeviceGLAdapter::
  38     ~CompositorSoftwareOutputDeviceGLAdapter() {
  39   Destroy();
  40 }
  41
  42 WebImage* CompositorSoftwareOutputDeviceGLAdapter::Lock(bool forWrite) {
  43   locked_for_write_ = forWrite;
  44   image_ = device_->accessBitmap(forWrite);
  45   return &image_;
  46 }
  47
  48 void CompositorSoftwareOutputDeviceGLAdapter::Unlock() {
  49   if (locked_for_write_)
  50     Draw(device_->accessBitmap(false).pixelRef()->pixels());
  51   image_.reset();
  52 }
  53
  54 void CompositorSoftwareOutputDeviceGLAdapter::DidChangeViewportSize(
  55     gfx::Size size) {
  56   if (!initialized_)
  57     Initialize();
  58
  59   if (framebuffer_texture_size_ != gfx::Size(size))
  60     Resize(size);
  61 }
  62
  63 void CompositorSoftwareOutputDeviceGLAdapter::Initialize() {
  64   // Vertex shader that flips the y axis.
  65   static const char g_vertex_shader[] =
  66     "attribute vec4 a_Position;"
  67     "attribute vec2 a_texCoord;"
  68     "varying vec2 v_texCoord;"
  69     "void main() {"
  70     "  gl_Position = a_Position;"
  71     "  gl_Position.y = -gl_Position.y;"
  72     "  v_texCoord = a_texCoord;"
  73     "}";
  74
  75   // Pixel shader that swizzles RGBA -> BGRA.
  76   static const char g_fragment_shader[] =
  77     "precision mediump float;"
  78     "varying vec2 v_texCoord;"
  79     "uniform sampler2D s_texture;"
  80     "void main() {"
  81     "  gl_FragColor = texture2D(s_texture, v_texCoord).bgra;"
  82     "}";
  83
  84   const GLfloat attribs[] = {
  85     -1.0f, -1.0f,
  86     1.0f, -1.0f,
  87     -1.0f, 1.0f,
  88     1.0f, 1.0f,
  89     0.0f, 0.0f,
  90     1.0f, 0.0f,
  91     0.0f, 1.0f,
  92     1.0f, 1.0f
  93   };
  94
  95   context3d_->makeContextCurrent();
  96
  97   vertex_shader_ = context3d_->createShader(GL_VERTEX_SHADER);
  98   context3d_->shaderSource(vertex_shader_, g_vertex_shader);
  99   context3d_->compileShader(vertex_shader_);
 100
 101   fragment_shader_ = context3d_->createShader(GL_FRAGMENT_SHADER);
 102   context3d_->shaderSource(fragment_shader_, g_fragment_shader);
 103   context3d_->compileShader(fragment_shader_);
 104
 105   program_ = context3d_->createProgram();
 106   context3d_->attachShader(program_, vertex_shader_);
 107   context3d_->attachShader(program_, fragment_shader_);
 108
 109   vertex_buffer_ = context3d_->createBuffer();
 110   context3d_->bindBuffer(GL_ARRAY_BUFFER, vertex_buffer_);
 111   context3d_->bufferData(GL_ARRAY_BUFFER, 16 * sizeof(float), attribs,
 112                          GL_STATIC_DRAW);
 113   context3d_->enableVertexAttribArray(0);
 114   context3d_->vertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);
 115   context3d_->bindAttribLocation(program_, 0, "a_Position");
 116   context3d_->enableVertexAttribArray(1);
 117   context3d_->vertexAttribPointer(
 118       1, 2, GL_FLOAT, GL_FALSE, 0, 8 * sizeof(GLfloat));
 119   context3d_->bindAttribLocation(program_, 1, "a_texCoord");
 120
 121   context3d_->linkProgram(program_);
 122   context3d_->useProgram(program_);
 123
 124   int texture_uniform = context3d_->getUniformLocation(program_, "s_texture");
 125   context3d_->uniform1i(texture_uniform, 0);
 126   context3d_->disable(GL_SCISSOR_TEST);
 127   context3d_->clearColor(0, 0, 1, 1);
 128
 129   initialized_ = true;
 130 }
 131
 132 void CompositorSoftwareOutputDeviceGLAdapter::Destroy() {
 133   if (!initialized_)
 134     return;
 135
 136   context3d_->makeContextCurrent();
 137   context3d_->deleteShader(vertex_shader_);
 138   context3d_->deleteShader(fragment_shader_);
 139   context3d_->deleteProgram(program_);
 140   context3d_->deleteBuffer(vertex_buffer_);
 141   if (framebuffer_texture_id_)
 142     context3d_->deleteTexture(framebuffer_texture_id_);
 143 }
 144
 145 void CompositorSoftwareOutputDeviceGLAdapter::Resize(
 146     const gfx::Size& viewport_size) {
 147   framebuffer_texture_size_ = viewport_size;
 148   device_.reset(new SkDevice(SkBitmap::kARGB_8888_Config,
 149       viewport_size.width(), viewport_size.height(), true));
 150
 151   context3d_->makeContextCurrent();
 152   context3d_->ensureBackbufferCHROMIUM();
 153   framebuffer_texture_id_ = context3d_->createTexture();
 154   context3d_->bindTexture(GL_TEXTURE_2D, framebuffer_texture_id_);
 155   context3d_->texParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 156   context3d_->texParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 157   context3d_->texParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 158   context3d_->texParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 159
 160   context3d_->viewport(0, 0, viewport_size.width(), viewport_size.height());
 161   context3d_->reshape(viewport_size.width(), viewport_size.height());
 162 }
 163
 164 void CompositorSoftwareOutputDeviceGLAdapter::Draw(void* pixels) {
 165   TRACE_EVENT0("renderer", "CompositorSoftwareOutputDeviceGLAdapter::Draw");
 166   if (!initialized_)
 167     NOTREACHED();
 168   if (!framebuffer_texture_id_)
 169     NOTREACHED();
 170
 171   context3d_->makeContextCurrent();
 172   context3d_->ensureBackbufferCHROMIUM();
 173   context3d_->clear(GL_COLOR_BUFFER_BIT);
 174
 175   context3d_->texImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
 176       framebuffer_texture_size_.width(), framebuffer_texture_size_.height(),
 177       0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
 178
 179   context3d_->drawArrays(GL_TRIANGLE_STRIP, 0, 4);
 180
 181   context3d_->prepareTexture();
 182 }
 183
 184 }  // namespace content