OffscreenBrowserCompositorOutputSurface for Unified Desktop

content/browser/compositor/offscreen_browser_compositor_output_surface.cc

+// 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 "content/browser/compositor/offscreen_browser_compositor_output_surface.h"
+
+#include "base/logging.h"
+#include "cc/output/compositor_frame.h"
+#include "cc/output/compositor_frame_ack.h"
+#include "cc/output/gl_frame_data.h"
+#include "cc/output/output_surface_client.h"
+#include "cc/resources/resource_provider.h"
+#include "content/browser/compositor/browser_compositor_overlay_candidate_validator.h"
+#include "content/browser/compositor/reflector_impl.h"
+#include "content/common/gpu/client/context_provider_command_buffer.h"
+#include "content/public/browser/browser_thread.h"
+#include "gpu/command_buffer/client/context_support.h"
+#include "gpu/command_buffer/client/gles2_interface.h"
+#include "third_party/khronos/GLES2/gl2.h"
+#include "third_party/khronos/GLES2/gl2ext.h"
+
+using cc::CompositorFrame;
+using cc::GLFrameData;
+using cc::ResourceProvider;
+using gpu::gles2::GLES2Interface;
+
+namespace content {
+
+OffscreenBrowserCompositorOutputSurface::
+    OffscreenBrowserCompositorOutputSurface(
+        const scoped_refptr<ContextProviderCommandBuffer>& context,
+        const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
+        scoped_ptr<BrowserCompositorOverlayCandidateValidator>
+            overlay_candidate_validator)
+    : BrowserCompositorOutputSurface(context,
+                                     vsync_manager,
+                                     overlay_candidate_validator.Pass()),
+      fbo_(0),
+      is_backbuffer_discarded_(false),
+      backing_texture_id_(0),
+      weak_ptr_factory_(this) {
+  capabilities_.max_frames_pending = 1;
+  capabilities_.uses_default_gl_framebuffer = false;
+}
+
+OffscreenBrowserCompositorOutputSurface::
+    ~OffscreenBrowserCompositorOutputSurface() {
+  DiscardBackbuffer();
+}
+
+void OffscreenBrowserCompositorOutputSurface::EnsureBackbuffer() {
+  is_backbuffer_discarded_ = false;
+
+  if (!backing_texture_id_) {
+    GLES2Interface* gl = context_provider_->ContextGL();
+    cc::ResourceFormat format = cc::RGBA_8888;
+
+    gl->GenTextures(1, &backing_texture_id_);
+    gl->BindTexture(GL_TEXTURE_2D, backing_texture_id_);
+    gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    gl->TexImage2D(GL_TEXTURE_2D, 0, GLInternalFormat(format),
+                   surface_size_.width(), surface_size_.height(), 0,
+                   GLDataFormat(format), GLDataType(format), nullptr);

[piman, 2015/04/28 18:38:13]

note: since you never use this one as a texture, only as a render target that
you render to and copy from, you can use a renderbuffer instead (it may be more
efficient).
Though if you are going to use this texture to avoid the copy, then it's fine to
leave as is.

[oshima, 2015/04/28 20:39:01]

Yes, I'm going to use this texture directly on the reflector's surface.

+  }
+}
+
+void OffscreenBrowserCompositorOutputSurface::DiscardBackbuffer() {
+  is_backbuffer_discarded_ = true;
+
+  GLES2Interface* gl = context_provider_->ContextGL();
+
+  if (backing_texture_id_) {
+    gl->DeleteTextures(1, &backing_texture_id_);
+    backing_texture_id_ = 0;
+  }
+
+  if (fbo_) {
+    gl->BindFramebuffer(GL_FRAMEBUFFER, fbo_);
+    gl->DeleteFramebuffers(1, &fbo_);
+    fbo_ = 0;
+  }
+}
+
+void OffscreenBrowserCompositorOutputSurface::Reshape(const gfx::Size& size,
+                                                      float scale_factor) {
+  if (size == surface_size_)
+    return;
+
+  surface_size_ = size;
+  device_scale_factor_ = scale_factor;
+  DiscardBackbuffer();
+  EnsureBackbuffer();
+}
+
+void OffscreenBrowserCompositorOutputSurface::BindFramebuffer() {
+  EnsureBackbuffer();
+  DCHECK(backing_texture_id_);
+
+  GLES2Interface* gl = context_provider_->ContextGL();
+
+  if (!fbo_)
+    gl->GenFramebuffers(1, &fbo_);
+  gl->BindFramebuffer(GL_FRAMEBUFFER, fbo_);
+  gl->FramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                           backing_texture_id_, 0);
+}
+
+void OffscreenBrowserCompositorOutputSurface::SwapBuffers(
+    cc::CompositorFrame* frame) {
+  // TODO(oshima): Pass the texture to the reflector so that the
+  // reflector can simply use and draw it on their surface instead of
+  // copying the texture.
+  if (reflector_) {
+    if (frame->gl_frame_data->sub_buffer_rect ==
+        gfx::Rect(frame->gl_frame_data->size))
+      reflector_->OnSourceSwapBuffers();
+    else
+      reflector_->OnSourcePostSubBuffer(frame->gl_frame_data->sub_buffer_rect);
+  }
+
+  client_->DidSwapBuffers();
+
+  // TODO(oshima): sync with the reflector's SwapBuffersComplete.
+  uint32_t sync_point =
+      context_provider_->ContextGL()->InsertSyncPointCHROMIUM();
+  context_provider_->ContextSupport()->SignalSyncPoint(
+      sync_point, base::Bind(&OutputSurface::OnSwapBuffersComplete,
+                             weak_ptr_factory_.GetWeakPtr()));
+}
+
+}  // namespace content