Re-land^2 WebVR compositor bypass via BrowserMain context + mailbox

chrome/browser/android/vr_shell/vr_shell_command_buffer_gl.cc

+// Copyright 2017 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 "chrome/browser/android/vr_shell/vr_shell_command_buffer_gl.h"
+
+#include "chrome/browser/android/vr_shell/vr_shell_gpu_renderer.h"
+#include "gpu/command_buffer/client/gles2_interface.h"
+#include "gpu/command_buffer/common/mailbox.h"
+#include "gpu/ipc/common/gpu_surface_tracker.h"
+#include "services/ui/public/cpp/gpu/context_provider_command_buffer.h"
+#include "ui/android/context_provider_factory.h"
+#include "ui/gl/android/surface_texture.h"
+
+#if defined(OS_ANDROID)

[mthiesse, 2017/03/02 15:55:16]

nit: Remove this for now? We're still in the Android directory.

[klausw, 2017/03/07 02:55:54]

Done.

+#include <android/native_window_jni.h>
+#endif
+namespace vr_shell {
+
+VrShellCommandBufferGl::VrShellCommandBufferGl() :
+    weak_ptr_factory_(this) {}
+
+VrShellCommandBufferGl::~VrShellCommandBufferGl() {}
+
+void VrShellCommandBufferGl::OnGpuChannelEstablished(
+    scoped_refptr<gpu::GpuChannelHost> gpu_channel_host,
+    ui::ContextProviderFactory::GpuChannelHostResult result) {
+
+  VLOG(1) << __FUNCTION__ << ";;;";
+  switch (result) {
+    // Don't retry if we are shutting down.

[mthiesse, 2017/03/02 15:55:16]

Also don't retry if initialization fails?

[klausw, 2017/03/07 02:55:55]

Moot, the switch no longer exists.

+    case ui::ContextProviderFactory::GpuChannelHostResult::
+        FAILURE_FACTORY_SHUTDOWN:
+      break;
+    case ui::ContextProviderFactory::GpuChannelHostResult::
+        FAILURE_GPU_PROCESS_INITIALIZATION_FAILED:
+      break;
+    case ui::ContextProviderFactory::GpuChannelHostResult::SUCCESS:
+      VLOG(1) << __FUNCTION__ << ";;; Success!";
+
+      const size_t full_screen_texture_size_in_bytes = 4000 * 3000 * 4;

[mthiesse, 2017/03/02 15:55:16]

Lots of magic numbers, where do these come from?

[klausw, 2017/03/07 02:55:54]

Replaced with gpu::SharedMemoryLimits::ForMailboxContext() at Brandon's
suggestion.

+      gpu::SharedMemoryLimits limits;
+      limits.command_buffer_size = 64 * 1024;
+      limits.start_transfer_buffer_size = 64 * 1024;
+      limits.min_transfer_buffer_size = 64 * 1024;
+      limits.max_transfer_buffer_size = full_screen_texture_size_in_bytes;
+      limits.mapped_memory_reclaim_limit = full_screen_texture_size_in_bytes;
+
+      gpu::gles2::ContextCreationAttribHelper attributes;
+      attributes.alpha_size = 0;
+      attributes.stencil_size = 0;
+      attributes.depth_size = 0;
+      attributes.samples = 0;
+      attributes.sample_buffers = 0;
+      attributes.bind_generates_resource = false;
+
+      bool automatic_flushes = false;
+      bool support_locking = false;
+      constexpr ui::ContextProviderCommandBuffer* shared_context_provider =
+          nullptr;
+      context_provider_command_buffer_ = make_scoped_refptr(
+          new ui::ContextProviderCommandBuffer(
+              std::move(gpu_channel_host), gpu::GPU_STREAM_DEFAULT,
+              gpu::GpuStreamPriority::NORMAL, surface_handle_,
+              GURL("chrome://gpu/MusContextFactory"), automatic_flushes,
+              support_locking, limits, attributes,
+              shared_context_provider,
+              ui::command_buffer_metrics::MUS_CLIENT_CONTEXT));
+
+      VLOG(1) << __FUNCTION__ << ";;; context_provider_command_buffer=" <<
+          context_provider_command_buffer_;
+      if (!context_provider_command_buffer_->BindToCurrentThread()) {
+        LOG(ERROR) << __FUNCTION__ << ";;; failed to init ContextProvider";
+        break;
+      }
+      VLOG(1) << __FUNCTION__ << ";;; bind succeeded";
+
+      gl_ = context_provider_command_buffer_->ContextGL();
+      VLOG(1) << __FUNCTION__ << ";;; gl_=" << gl_;
+
+      break;
+  }
+}
+
+void VrShellCommandBufferGl::CreateContext(
+    scoped_refptr<gl::SurfaceTexture> surface_texture) {
+  ANativeWindow* window = surface_texture->CreateSurface();
+  gpu::GpuSurfaceTracker* tracker = gpu::GpuSurfaceTracker::Get();
+  ANativeWindow_acquire(window);
+  // setBuffersGeometry seems optional, it uses the SurfaceTexture's
+  // default size by default?
+  // ANativeWindow_setBuffersGeometry(
+  //   window, 2048, 1024, WINDOW_FORMAT_RGBA_8888); // FIXME!
+  surface_handle_ = tracker->AddSurfaceForNativeWidget(window);
+  VLOG(1) << __FUNCTION__ << ";;;: surface_handle_=" << surface_handle_;
+
+  auto surface = base::MakeUnique<gl::ScopedJavaSurface>(surface_texture.get());
+  tracker->RegisterViewSurface(
+      surface_handle_, surface->j_surface().obj());
+  // When should this be released? Does registering it keep it alive?

[mthiesse, 2017/03/02 15:55:16]

Is this relevant?
https://codereview.chromium.org/2584343002/diff/60001/chrome/browser/android/...

[klausw, 2017/03/07 02:55:54]

It is indeed, added unregistration to destructor.

+  ANativeWindow_release(window);
+
+  VLOG(1) << __FUNCTION__ << ";;; RequestGpuChannelHost start";
+  ui::ContextProviderFactory::GetInstance()->RequestGpuChannelHost(base::Bind(
+      &VrShellCommandBufferGl::OnGpuChannelEstablished,
+      weak_ptr_factory_.GetWeakPtr()));
+  VLOG(1) << __FUNCTION__ << ";;; RequestGpuChannelHost end";
+}
+
+bool VrShellCommandBufferGl::CopyFrameToSurface(
+    int frame_index, const gpu::Mailbox& mailbox, bool discard) {
+  auto gl = GetContext();;
+  if (!gl) {
+    VLOG(1) << __FUNCTION__ << ";;; drop, no GL context";
+    return false;
+  }
+  VLOG(1) << __FUNCTION__ << ";;; frame=" << frame_index << " gl=" << gl;
+
+  // Default viewport size seems ok, don't set one here and leave it
+  // alone elsewhere.
+  // gl->Viewport(0, 0, 2560, 1440); // FIXME!
+
+  // TODO(klausw): make this a proper member
+  static GpuRenderer* copyRenderer = nullptr;
+  if (!copyRenderer) {
+    copyRenderer = new GpuRenderer(gl);
+  }
+
+  VLOG(1) << __FUNCTION__ << ";;; got mailbox, name=" <<
+      static_cast<int>(mailbox.name[0]) << "," <<
+      static_cast<int>(mailbox.name[1]) << "," <<
+      static_cast<int>(mailbox.name[2]) << "," <<
+      static_cast<int>(mailbox.name[3]) << "," <<
+      static_cast<int>(mailbox.name[4]) << "," <<
+      static_cast<int>(mailbox.name[5]) << "," <<
+      static_cast<int>(mailbox.name[6]) << "," <<
+      static_cast<int>(mailbox.name[7]) << "," <<
+      static_cast<int>(mailbox.name[8]) << "," <<
+      static_cast<int>(mailbox.name[9]) << "," <<
+      static_cast<int>(mailbox.name[10]) << "," <<
+      static_cast<int>(mailbox.name[11]) << "," <<
+      static_cast<int>(mailbox.name[12]) << "," <<
+      static_cast<int>(mailbox.name[13]) << "," <<
+      static_cast<int>(mailbox.name[14]) << "," <<
+      static_cast<int>(mailbox.name[15]);
+  GLuint vrSourceTexture = gl->CreateAndConsumeTextureCHROMIUM(
+      GL_TEXTURE_2D, mailbox.name);
+  VLOG(1) << __FUNCTION__ << ";;; vrSourceTexture=" << vrSourceTexture;
+
+  bool skip_this_frame = false;
+
+  if (discard) {
+    // We've consumed the texture, but we can't draw it to the surface, the
+    // previous one hasn't been consumed yet. Swapping twice loses frames.
+    // This should be rare, it's a waste of resources and can suppress useful
+    // frames.
+    VLOG(1) << __FUNCTION__ << ";;; Dropping frame, got one queued already.";
+    skip_this_frame = true;
+  }
+
+  VLOG(1) << __FUNCTION__ << ";;; Draw start";
+  copyRenderer->DrawQuad(gl, vrSourceTexture);
+  VLOG(1) << __FUNCTION__ << ";;; Draw done";
+
+  if (skip_this_frame) {
+    VLOG(1) << __FUNCTION__ << ";;; drop frame=" << frame_index;
+    return false;
+  }
+
+  // This is a load-bearing glFlush(). Removing it breaks rendering. WTF.
+  // FIXME: check if this is still true.
+  gl->Flush();
+  gl->SwapBuffers();
+  gl->Flush();
+  VLOG(1) << __FUNCTION__ << ";;; Swap/flush done";
+  return true;
+}
+
+} // namespace vr_shell