WebVR compositor bypass via BrowserMain context + mailbox

chrome/browser/android/vr_shell/vr_shell_gl.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_
 
 #include <memory>
 #include <queue>
 #include <utility>
@@ skipping 19 matching lines @@
 class WebInputEvent;
 }
 
 namespace gl {
 class GLContext;
 class GLSurface;
 class ScopedJavaSurface;
 class SurfaceTexture;
 }
 
+namespace gpu {
+struct MailboxHolder;
+}
+
 namespace vr_shell {
 
 class UiScene;
 class VrController;
 class VrShell;
+class VrShellCommandBufferGl;
 class VrShellDelegate;
 class VrShellRenderer;
 struct ContentRectangle;
 
+class WebVrBounds {
+ public:
+  WebVrBounds(gvr::Rectf left, gvr::Rectf right, gvr::Sizei size)
+      : left_bounds(left), right_bounds(right), source_size(size) {}
+  gvr::Rectf left_bounds;
+  gvr::Rectf right_bounds;
+  gvr::Sizei source_size;
+};
+
 // This class manages all GLThread owned objects and GL rendering for VrShell.
 // It is not threadsafe and must only be used on the GL thread.
 class VrShellGl : public device::mojom::VRVSyncProvider {
  public:
   enum class InputTarget {
     NONE = 0,
     CONTENT,
     UI,
   };
 
   VrShellGl(const base::WeakPtr<VrShell>& weak_vr_shell,
             const base::WeakPtr<VrShellDelegate>& delegate_provider,
             scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
             gvr_context* gvr_api,
             bool initially_web_vr,
             bool reprojected_rendering);
   ~VrShellGl() override;
 
   void Initialize();
   void InitializeGl(gfx::AcceleratedWidget window);
 
   void OnTriggerEvent();
   void OnPause();
   void OnResume();
 
   void SetWebVrMode(bool enabled);
+  void CreateOrResizeWebVRSurface(const gvr::Sizei& size);
   void CreateContentSurface();
   void ContentBoundsChanged(int width, int height);
   void ContentPhysicalBoundsChanged(int width, int height);
   void UIBoundsChanged(int width, int height);
   void UIPhysicalBoundsChanged(int width, int height);
   base::WeakPtr<VrShellGl> GetWeakPtr();
 
   void UpdateWebVRTextureBounds(int16_t frame_index,
                                 const gvr::Rectf& left_bounds,
-                                const gvr::Rectf& right_bounds);
-  gvr::Sizei GetWebVRCompositorSurfaceSize();
+                                const gvr::Rectf& right_bounds,
+                                const gvr::Sizei& source_size);
 
   void UpdateScene(std::unique_ptr<base::ListValue> commands);
 
   void UpdateVSyncInterval(int64_t timebase_nanos, double interval_seconds);
 
   void OnRequest(device::mojom::VRVSyncProviderRequest request);
   void ResetPose();
   void CreateVRDisplayInfo(
       const base::Callback<void(device::mojom::VRDisplayInfoPtr)>& callback,
       uint32_t device_id);
+  void SubmitWebVRFrame(int16_t frame_index, const gpu::MailboxHolder& mailbox);
 
  private:
   void GvrInit(gvr_context* gvr_api);
   void InitializeRenderer();
-  void DrawFrame();
-  void DrawVrShell(const gvr::Mat4f& head_pose, gvr::Frame& frame);
+  void DrawFrame(int frame_index);
+  void DrawVrShellAndUnbind(const gvr::Mat4f& head_pose, gvr::Frame& frame);
   void DrawUiView(const gvr::Mat4f* head_pose,
                   const std::vector<const ContentRectangle*>& elements,
                   const gvr::Sizei& render_size,
                   int viewport_offset);
   void DrawElements(const gvr::Mat4f& view_proj_matrix,
                     const gvr::Mat4f& view_matrix,
                     const std::vector<const ContentRectangle*>& elements);
   std::vector<const ContentRectangle*> GetElementsInDrawOrder(
       const gvr::Mat4f& view_matrix,
       const std::vector<const ContentRectangle*>& elements);
   void DrawCursor(const gvr::Mat4f& render_matrix);
   void DrawWebVr();
   bool WebVrPoseByteIsValid(int pose_index_byte);
 
   void UpdateController(const gvr::Vec3f& forward_vector);
   void SendEventsToTarget(InputTarget input_target, int pixel_x, int pixel_y);
   void SendGesture(InputTarget input_target,
                    std::unique_ptr<blink::WebInputEvent> event);
   void CreateUiSurface();
   void OnUIFrameAvailable();
   void OnContentFrameAvailable();
+  void OnWebVRFrameAvailable();
   bool GetPixelEncodedFrameIndex(uint16_t* frame_index);
 
   void OnVSync();
 
   // VRVSyncProvider
   void GetVSync(const GetVSyncCallback& callback) override;
 
   void ForceExitVr();
 
   void SendVSync(base::TimeDelta time, const GetVSyncCallback& callback);
 
   // samplerExternalOES texture data for UI content image.
   int ui_texture_id_ = 0;
   // samplerExternalOES texture data for main content image.
   int content_texture_id_ = 0;
+  // samplerExternalOES texture data for WebVR content image.
+  int webvr_texture_id_ = 0;
 
   std::unique_ptr<UiScene> scene_;
 
   scoped_refptr<gl::GLSurface> surface_;
   scoped_refptr<gl::GLContext> context_;
   scoped_refptr<gl::SurfaceTexture> ui_surface_texture_;
   scoped_refptr<gl::SurfaceTexture> content_surface_texture_;
+  scoped_refptr<gl::SurfaceTexture> webvr_surface_texture_;
 
   std::unique_ptr<gl::ScopedJavaSurface> ui_surface_;
   std::unique_ptr<gl::ScopedJavaSurface> content_surface_;
+  std::unique_ptr<gl::ScopedJavaSurface> webvr_surface_;
 
   std::unique_ptr<gvr::GvrApi> gvr_api_;
   std::unique_ptr<gvr::BufferViewportList> buffer_viewport_list_;
   std::unique_ptr<gvr::BufferViewport> buffer_viewport_;
   std::unique_ptr<gvr::BufferViewport> headlocked_left_viewport_;
   std::unique_ptr<gvr::BufferViewport> headlocked_right_viewport_;
   std::unique_ptr<gvr::BufferViewport> webvr_left_viewport_;
   std::unique_ptr<gvr::BufferViewport> webvr_right_viewport_;
   std::unique_ptr<gvr::SwapChain> swap_chain_;
-  using BoundsPair = std::pair<gvr::Rectf, gvr::Rectf>;
-  std::queue<std::pair<uint8_t, BoundsPair>> pending_bounds_;
+  std::queue<std::pair<uint8_t, WebVrBounds>> pending_bounds_;
+  int premature_received_frames_ = 0;
+  std::queue<uint16_t> pending_frames_;
+  std::unique_ptr<VrShellCommandBufferGl> command_buffer_gl_;
 
   // Current sizes for the render buffers.
   gvr::Sizei render_size_primary_;
   gvr::Sizei render_size_headlocked_;
 
+  // Intended render_size_primary_ for use by VrShell, so that it
+  // can be restored after exiting WebVR mode.
+  gvr::Sizei render_size_vrshell_;
+
   std::unique_ptr<VrShellRenderer> vr_shell_renderer_;
 
   bool touch_pending_ = false;
   gvr::Quatf controller_quat_;
 
   gvr::Vec3f target_point_;
   const ContentRectangle* target_element_ = nullptr;
   InputTarget current_input_target_ = InputTarget::NONE;
   InputTarget current_scroll_target = InputTarget::NONE;
   int ui_tex_css_width_ = 0;
   int ui_tex_css_height_ = 0;
   int content_tex_css_width_ = 0;
   int content_tex_css_height_ = 0;
   gvr::Sizei content_tex_physical_size_ = {0, 0};
+  gvr::Sizei webvr_surface_size_ = {0, 0};
   gvr::Sizei ui_tex_physical_size_ = {0, 0};
 
   std::vector<gvr::Mat4f> webvr_head_pose_;
-  int webvr_texture_id_ = 0;
   bool web_vr_mode_;
   bool ready_to_draw_ = false;
   bool surfaceless_rendering_;
 
   std::unique_ptr<VrController> controller_;
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   base::CancelableClosure vsync_task_;
   base::TimeTicks vsync_timebase_;
   base::TimeDelta vsync_interval_;
@@ skipping 13 matching lines @@
   uint16_t last_frame_index_ = -1;
 
   base::WeakPtrFactory<VrShellGl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VrShellGl);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_