LookingGlass/idd/LGIdd/CSwapChainProcessor.h

/**
 * Looking Glass
 * Copyright © 2017-2023 The Looking Glass Authors
 * https://looking-glass.io
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#pragma once

#include "Direct3DDevice.h"
#include "CIndirectDeviceContext.h"

#include <Windows.h>
#include <wrl.h>
#include <IddCx.h>
#include <memory>

using namespace Microsoft::WRL;

#define STAGING_TEXTURES 3

class CSwapChainProcessor
{
private:
  CIndirectDeviceContext        * m_devContext;
  IDDCX_SWAPCHAIN                 m_hSwapChain;
  std::shared_ptr<Direct3DDevice> m_device;
  HANDLE                          m_newFrameEvent;

  Wrappers::HandleT<Wrappers::HandleTraits::HANDLENullTraits> m_thread[2];
  Wrappers::Event m_terminateEvent;

  static DWORD CALLBACK _SwapChainThread(LPVOID arg);
  static DWORD CALLBACK _FrameThread(LPVOID arg);

  void SwapChainThread();
  void SwapChainThreadCore();
  void SwapChainNewFrame(ComPtr<IDXGIResource> acquiredBuffer);

  void FrameThread();

  struct StagingTexture
  {
    volatile LONG lock = 0;

    int         width  = 0;
    int         height = 0;
    DXGI_FORMAT format = DXGI_FORMAT_UNKNOWN;
    Microsoft::WRL::ComPtr<ID3D11Texture2D> tex;
    D3D11_MAPPED_SUBRESOURCE map = {};
  };

  StagingTexture m_cpuTex[STAGING_TEXTURES] = {};
  volatile LONG m_copyCount   = 0;
  volatile LONG m_contextLock = 0;
  int m_texRIndex = 0;
  int m_texWIndex = 0;
  int m_lastIndex = 0;

  bool SetupStagingTexture(StagingTexture & st, int width, int height, DXGI_FORMAT format);

public:
  CSwapChainProcessor(CIndirectDeviceContext * devContext, IDDCX_SWAPCHAIN hSwapChain,
    std::shared_ptr<Direct3DDevice> device, HANDLE newFrameEvent);
  ~CSwapChainProcessor();

  void ResendLastFrame();
};