/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "VRLayerChild.h"

#include "gfxPlatform.h"

#include "GLScreenBuffer.h"

#include "mozilla/layers/TextureClientSharedSurface.h"

#include "SharedSurface.h"                // for SharedSurface

#include "SharedSurfaceGL.h"              // for SharedSurface

#include "mozilla/layers/LayersMessages.h" // for TimedTexture

#include "nsICanvasRenderingContextInternal.h"

#include "mozilla/dom/HTMLCanvasElement.h"

#include "mozilla/layers/SyncObject.h" // for SyncObjectClient

namespace mozilla {

namespace gfx {

VRLayerChild::VRLayerChild()

  : mCanvasElement(nullptr)

  , mIPCOpen(false)

  , mLastSubmittedFrameId(0)

{

  MOZ_COUNT_CTOR(VRLayerChild);

}

VRLayerChild::~VRLayerChild()

{

  ClearSurfaces();

  MOZ_COUNT_DTOR(VRLayerChild);

}

void

VRLayerChild::Initialize(dom::HTMLCanvasElement* aCanvasElement,

                         const gfx::Rect& aLeftEyeRect, const gfx::Rect& aRightEyeRect)

{

  MOZ_ASSERT(aCanvasElement);

  mLeftEyeRect = aLeftEyeRect;

  mRightEyeRect = aRightEyeRect;

  if (mCanvasElement == nullptr) {

    mCanvasElement = aCanvasElement;

    VRManagerChild *vrmc = VRManagerChild::Get();

    vrmc->RunFrameRequestCallbacks();

  } else {

    mCanvasElement = aCanvasElement;

  }

}

void

VRLayerChild::SubmitFrame(const VRDisplayInfo& aDisplayInfo)

{

  uint64_t frameId = aDisplayInfo.GetFrameId();

  // aFrameId will not increment unless the previuosly submitted

  // frame was received by the VR thread and submitted to the VR

  // compositor.  We early-exit here in the event that SubmitFrame

  // was called twice for the same aFrameId.

  if (!mCanvasElement || frameId == mLastSubmittedFrameId) {

    return;

  }

  // Keep the SharedSurfaceTextureClient alive long enough for

  // 1 extra frame, accomodating overlapped asynchronous rendering.

  mLastFrameTexture = mThisFrameTexture;

#if defined(MOZ_WIDGET_ANDROID)

  /**

   * Do not blit WebGL to a SurfaceTexture until the last submitted frame is already processed

   * and the new frame poses are ready. SurfaceTextures need to be released in the VR render thread 

   * in order to allow to be used again in the WebGLContext GLScreenBuffer producer.

   * Not doing so causes some freezes, crashes or other undefined behaviour.

   */

  if (!mThisFrameTexture || aDisplayInfo.mDisplayState.mLastSubmittedFrameId == mLastSubmittedFrameId) {

      mThisFrameTexture = mCanvasElement->GetVRFrame();

  }

#else

  mThisFrameTexture = mCanvasElement->GetVRFrame();

#endif // defined(MOZ_WIDGET_ANDROID)

  mLastSubmittedFrameId = frameId;

  if (!mThisFrameTexture) {

    return;

  }

  VRManagerChild* vrmc = VRManagerChild::Get();

  layers::SyncObjectClient* syncObject = vrmc->GetSyncObject();

  mThisFrameTexture->SyncWithObject(syncObject);

  if (!gfxPlatform::GetPlatform()->DidRenderingDeviceReset()) {

    if (syncObject && syncObject->IsSyncObjectValid()) {

      syncObject->Synchronize();

    }

  }

  gl::SharedSurface* surf = mThisFrameTexture->Surf();

  if (surf->mType == gl::SharedSurfaceType::Basic) {

    gfxCriticalError() << "SharedSurfaceType::Basic not supported for WebVR";

    return;

  }

  layers::SurfaceDescriptor desc;

  if (!surf->ToSurfaceDescriptor(&desc)) {

    gfxCriticalError() << "SharedSurface::ToSurfaceDescriptor failed in VRLayerChild::SubmitFrame";

    return;

  }

  SendSubmitFrame(desc, frameId, mLeftEyeRect, mRightEyeRect);

}

bool

VRLayerChild::IsIPCOpen()

{

  return mIPCOpen;

}

void

VRLayerChild::ClearSurfaces()

{

  mThisFrameTexture = nullptr;

  mLastFrameTexture = nullptr;

}

void

VRLayerChild::ActorDestroy(ActorDestroyReason aWhy)

{

  mIPCOpen = false;

}

// static

PVRLayerChild*

VRLayerChild::CreateIPDLActor()

{

  VRLayerChild* c = new VRLayerChild();

  c->AddIPDLReference();

  return c;

}

// static

bool

VRLayerChild::DestroyIPDLActor(PVRLayerChild* actor)

{

  static_cast<VRLayerChild*>(actor)->ReleaseIPDLReference();

  return true;

}

void

VRLayerChild::AddIPDLReference() {

  MOZ_ASSERT(mIPCOpen == false);

  mIPCOpen = true;

  AddRef();

}

void

VRLayerChild::ReleaseIPDLReference() {

  MOZ_ASSERT(mIPCOpen == false);

  Release();

}

} // namespace gfx

} // namespace mozilla