gfx/vr/FxROutputHandler.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "FxROutputHandler.h"
   7 #include "mozilla/Assertions.h"
   8 #include "moz_external_vr.h"
   9 #include "VRShMem.h"
  10
  11 // TryInitialize is responsible for associating this output handler with the
  12 // calling window's swapchain for subsequent updates. This also creates a
  13 // texture that can be shared across processes and updates VRShMem with the
  14 // shared texture handle.
  15 // See nsFxrCommandLineHandler::Handle for more information about the
  16 // bootstrap process.
  17 bool FxROutputHandler::TryInitialize(IDXGISwapChain* aSwapChain,
  18                                      ID3D11Device* aDevice) {
  19   if (mSwapChain == nullptr) {
  20     RefPtr<ID3D11Texture2D> texOrig = nullptr;
  21     HRESULT hr =
  22         aSwapChain->GetBuffer(0, IID_ID3D11Texture2D, getter_AddRefs(texOrig));
  23     if (hr != S_OK) {
  24       return false;
  25     }
  26
  27     // Create shareable texture, which will be copied to
  28     D3D11_TEXTURE2D_DESC descOrig = {0};
  29     texOrig->GetDesc(&descOrig);
  30     descOrig.MiscFlags |=
  31         D3D11_RESOURCE_MISC_SHARED_NTHANDLE | D3D11_RESOURCE_MISC_SHARED;
  32     hr = aDevice->CreateTexture2D(&descOrig, nullptr,
  33                                   mTexCopy.StartAssignment());
  34     if (hr != S_OK) {
  35       return false;
  36     }
  37
  38     // Now, share the texture to a handle that can be marshaled to another
  39     // process
  40     HANDLE hCopy = nullptr;
  41     RefPtr<IDXGIResource1> texResource;
  42     hr = mTexCopy->QueryInterface(IID_IDXGIResource1,
  43                                   getter_AddRefs(texResource));
  44     if (hr != S_OK) {
  45       return false;
  46     }
  47
  48     hr = texResource->CreateSharedHandle(
  49         nullptr, DXGI_SHARED_RESOURCE_READ | DXGI_SHARED_RESOURCE_WRITE,
  50         nullptr, &hCopy);
  51     if (hr != S_OK) {
  52       return false;
  53     }
  54
  55     // The texture is successfully created and shared, so cache a
  56     // pointer to the swapchain to indicate this success.
  57     mSwapChain = aSwapChain;
  58
  59     // Finally, marshal the shared texture handle via VRShMem
  60     mozilla::gfx::VRShMem shmem(nullptr, true /*aRequiresMutex*/);
  61     if (shmem.JoinShMem()) {
  62       mozilla::gfx::VRWindowState windowState = {0};
  63       shmem.PullWindowState(windowState);
  64
  65       // The CLH should have populated hwndFx first
  66       MOZ_ASSERT(windowState.hwndFx != 0);
  67       MOZ_ASSERT(windowState.textureFx == nullptr);
  68
  69       windowState.textureFx = (HANDLE)hCopy;
  70
  71       shmem.PushWindowState(windowState);
  72       shmem.LeaveShMem();
  73
  74       // Notify the waiting host process that the data is now available
  75       HANDLE hSignal = ::OpenEventA(EVENT_ALL_ACCESS,       // dwDesiredAccess
  76                                     FALSE,                  // bInheritHandle
  77                                     windowState.signalName  // lpName
  78       );
  79       ::SetEvent(hSignal);
  80       ::CloseHandle(hSignal);
  81     }
  82   } else {
  83     MOZ_ASSERT(aSwapChain == mSwapChain);
  84   }
  85
  86   return mSwapChain != nullptr && aSwapChain == mSwapChain;
  87 }
  88
  89 // Update the contents of the shared texture.
  90 void FxROutputHandler::UpdateOutput(ID3D11DeviceContext* aCtx) {
  91   MOZ_ASSERT(mSwapChain != nullptr);
  92
  93   ID3D11Texture2D* texOrig = nullptr;
  94   HRESULT hr = mSwapChain->GetBuffer(0, IID_PPV_ARGS(&texOrig));
  95   if (hr == S_OK) {
  96     aCtx->CopyResource(mTexCopy, texOrig);
  97     texOrig->Release();
  98   }
  99 }