HMDState* HMDState::CreateHMDState(NetClient* client, const HMDNetworkInfo& netInfo)
{
    // HMDState works through a handle to service HMD....
    HMDInfo hinfo;
    if (!client->Hmd_GetHmdInfo(netInfo.NetId, &hinfo))
    {
        OVR_DEBUG_LOG(("[HMDState] Unable to get HMD info"));
        return nullptr;
    }

#if !defined(HEADLESS_APP)
#ifdef OVR_OS_WIN32
    OVR_DEBUG_LOG(("[HMDState] Setting up display shim"));

    // Initialize the display shim before reporting the display to the user code
    // so that this will happen before the D3D display object is created.
    Win32::DisplayShim::GetInstance().Update(&hinfo.ShimInfo);
#endif
#endif /* !defined(HEADLESS_APP) */

    Ptr<Profile> pDefaultProfile = *ProfileManager::GetInstance()->GetDefaultUserProfile(&hinfo);
    OVR_DEBUG_LOG(("[HMDState] Using profile %s", pDefaultProfile->GetValue(OVR_KEY_USER)));

    HMDState* hmds = new HMDState(hinfo, pDefaultProfile, &netInfo, client);

    if (!hmds->InitializeSharedState())
    {
        delete hmds;
        return nullptr;
    }

    return hmds;
}

HMDState* HMDState::CreateHMDState(NetClient* client, const HMDNetworkInfo& netInfo)
{
    // HMDState works through a handle to service HMD....
    HMDInfo hinfo;
    if (!client->Hmd_GetHmdInfo(netInfo.NetId, &hinfo))
    {
        OVR_DEBUG_LOG(("[HMDState] Unable to get HMD info"));
        return NULL;
    }

#ifdef OVR_OS_WIN32
    OVR_DEBUG_LOG(("Setting up display shim"));

    // Initialize the display shim before reporting the display to the user code
    // so that this will happen before the D3D display object is created.
    Win32::DisplayShim::GetInstance().Update(&hinfo.ShimInfo);
#endif

    Ptr<Profile> pDefaultProfile = *ProfileManager::GetInstance()->GetDefaultUserProfile(&hinfo);
    OVR_DEBUG_LOG(("Using profile %s", pDefaultProfile->GetValue(OVR_KEY_USER)));

    HMDState* hmds = new HMDState(netInfo, hinfo, pDefaultProfile, client);

    if (!hmds->SharedStateReader.Open(netInfo.SharedMemoryName.ToCStr()))
    {
        delete hmds;
        return NULL;
    }

    hmds->TheSensorStateReader.SetUpdater(hmds->SharedStateReader.Get());
    hmds->TheLatencyTestStateReader.SetUpdater(hmds->SharedStateReader.Get());

    return hmds;
}

void OculusWorldDemoApp::InitMainFilePath()
{
    // We try alternative relative locations for the file.
    const String contentBase = pPlatform->GetContentDirectory() + "/" + WORLDDEMO_ASSET_PATH;
    const char* baseDirectories[] = { "",
                                      contentBase.ToCStr(),
                                      #ifdef SHRDIR
                                          #define STR1(x) #x
                                          #define STR(x)  STR1(x)
                                          STR(SHRDIR) "/OculusWorldDemo/Assets/Tuscany/"
                                      #endif
                                      };
    String newPath;

    for(size_t i = 0; i < OVR_ARRAY_COUNT(baseDirectories); ++i)
    {
        newPath  = baseDirectories[i];
        newPath += WORLDDEMO_ASSET_FILE;

        OVR_DEBUG_LOG(("Trying to load the scene at: %s...", newPath.ToCStr()));

        if (SysFile(newPath).IsValid())
        {
            OVR_DEBUG_LOG(("Success loading %s", newPath.ToCStr()));
            MainFilePath = newPath;
            return;
        }
    }

    OVR_DEBUG_LOG(("Unable to find any version of %s. Do you have your working directory set right?", WORLDDEMO_ASSET_FILE));
}

void PerformanceTimer::Initialize()
{
    #if defined(OVR_OS_WIN32) // Desktop Windows only
        // The following has the effect of setting the NT timer resolution (NtSetTimerResolution) to 1 millisecond.
        MMRESULT mmr = timeBeginPeriod(1);
        OVR_ASSERT(TIMERR_NOERROR == mmr);
        OVR_UNUSED(mmr);
    #endif

    InitializeCriticalSection(&TimeCS);
    MMTimeWrapCounter = 0;
    getFrequency();

    #if defined(OVR_OS_WIN32) // Desktop Windows only
	    // Set Vista flag.  On Vista, we can just use QPC() without all the extra work
        OSVERSIONINFOEX ver;
	    ZeroMemory(&ver, sizeof(OSVERSIONINFOEX));
	    ver.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
	    ver.dwMajorVersion = 6; // Vista+

        DWORDLONG condMask = 0;
        VER_SET_CONDITION(condMask, VER_MAJORVERSION, VER_GREATER_EQUAL);

	    // VerifyVersionInfo returns true if the OS meets the conditions set above
	    UsingVistaOrLater = VerifyVersionInfo(&ver, VER_MAJORVERSION, condMask) != 0;
    #else
        UsingVistaOrLater = true;
    #endif

	OVR_DEBUG_LOG(("PerformanceTimer UsingVistaOrLater = %d", (int)UsingVistaOrLater));

    #if defined(OVR_BUILD_DEBUG) && defined(OVR_OS_WIN32)
        HMODULE hNtDll = LoadLibrary(L"NtDll.dll");
        if (hNtDll)
        {
            pNtQueryTimerResolution = (NtQueryTimerResolutionType)GetProcAddress(hNtDll, "NtQueryTimerResolution");
          //pNtSetTimerResolution = (NtSetTimerResolutionType)GetProcAddress(hNtDll, "NtSetTimerResolution");

            if(pNtQueryTimerResolution)
            {
                ULONG MinimumResolution; // in 100-ns units
                ULONG MaximumResolution;
                ULONG ActualResolution;
                pNtQueryTimerResolution(&MinimumResolution, &MaximumResolution, &ActualResolution);
	            OVR_DEBUG_LOG(("NtQueryTimerResolution = Min %ld us, Max %ld us, Current %ld us", MinimumResolution / 10, MaximumResolution / 10, ActualResolution / 10));
            }

            FreeLibrary(hNtDll);
        }
    #endif
}

//-----------------------------------------------------------------------------
bool HIDDevice::GetFeatureReport(UByte* data, UInt32 length)
{
    if (DeviceHandle < 0)
        return false;

	int skipped_report_id = 0;
	int report_number = data[0];

	if (report_number == 0x0) {
		/* Offset the return buffer by 1, so that the report ID
		   will remain in byte 0. */
		data++;
		length--;
		skipped_report_id = 1;
	}

	int r = hid_get_feature_report(DeviceHandle, data, length);
//  int r = ioctl(DeviceHandle, HIDIOCGFEATURE(length), data);

	if(r < 0)
	{
		OVR_DEBUG_LOG(("Error in LibOVR GetFeatureReport: %s",strerror(errno)));
	}

    return (r >= 0);
}

bool SensorFusion::AttachToSensor(SensorDevice* sensor)
{
    
    if (sensor != NULL)
    {
        MessageHandler* pCurrentHandler = sensor->GetMessageHandler();

        if (pCurrentHandler == &Handler)
        {
            Reset();
            return true;
        }

        if (pCurrentHandler != NULL)
        {
            OVR_DEBUG_LOG(
                ("SensorFusion::AttachToSensor failed - sensor %p already has handler", sensor));
            return false;
        }
    }

    if (Handler.IsHandlerInstalled())
    {
        Handler.RemoveHandlerFromDevices();
    }

    if (sensor != NULL)
    {
        sensor->SetMessageHandler(&Handler);
    }

    Reset();
    return true;
}

bool LatencyTest::SetDevice(LatencyTestDevice* device)
{

    if (device != Device)
    {
        if (device != NULL)
        {
            if (device->GetMessageHandler() != NULL)
            {
                OVR_DEBUG_LOG(
                    ("LatencyTest::AttachToDevice failed - device %p already has handler", device));
                return false;
            }
        }

        if (Device != NULL)
        {
            Device->SetMessageHandler(0);
        }
        Device = device;

        if (Device != NULL)
        {
            Device->SetMessageHandler(&Handler);

            // Set trigger threshold.
            LatencyTestConfiguration configuration(SENSOR_DETECT_THRESHOLD, false);     // No samples streaming.
            Device->SetConfiguration(configuration, true);
        }
    }

    return true;
}

bool Thread::Start(ThreadState initialState)
{
    if (initialState == NotRunning)
        return 0;
    if (GetThreadState() != NotRunning)
    {
        OVR_DEBUG_LOG(("Thread::Start failed - thread %p already running", this));
        return 0;
    }

    // Free old thread handle before creating the new one
    CleanupSystemThread();

    ExitCode        = NULL;
    ThreadFlags     = (initialState == Running) ? OVR_THREAD_STARTED : OVR_THREAD_START_SUSPENDED;
    ThreadHandle = (HANDLE) _beginthreadex(0, (unsigned)StackSize,
                                           Thread_Win32StartFn, this, 0, (unsigned*)&IdValue);

    // Failed? Fail the function
    if (ThreadHandle == 0)
    {
        ThreadFlags = 0;
        return 0;
    }
    return 1;
}

// Initializes System core, installing allocator.
void System::Init()
{
    #if defined(_MSC_VER)
        // Make it so that failure of the C malloc family of functions results in the same behavior as C++ operator new failure.
        // This allows us to throw exceptions for malloc usage the same as for operator new bad_alloc.
        _set_new_mode(1);

        // Tells the standard library to direct new (and malloc) failures to us. Normally we wouldn't need to do this, as the 
        // C++ Standard Library already throws std::bad_alloc on operator new failure. The problem is that the Standard Library doesn't
        // throw std::bad_alloc upon malloc failure, and we can only intercept malloc failure via this means. _set_new_handler specifies
        // a global handler for the current running Standard Library. If the Standard Library is being dynamically linked instead
        // of statically linked, then this is a problem because a call to _set_new_handler would override anything the application
        // has already set.
        _set_new_handler(OVRNewFailureHandler);
    #else
        // This allows us to throw OVR::bad_alloc instead of std::bad_alloc, which provides less information.
        // Question: Does this set the handler for all threads or just the current thread? The C++ Standard doesn't 
        // explicitly state this, though it may be implied from other parts of the Standard.
        std::set_new_handler(OVRNewFailureHandler);
    #endif

    if (++System_Init_Count == 1)
    {
        Timer::initializeTimerSystem();
    }
    else
    {
        OVR_DEBUG_LOG(("[System] Init recursively called; depth = %d", System_Init_Count));
    }
}

bool HIDDevice::openDevice()
{
    memset(&ReadOverlapped, 0, sizeof(OVERLAPPED));

    Device = HIDManager->CreateHIDFile(DevDesc.Path.ToCStr());
    if (Device == INVALID_HANDLE_VALUE)
    {
        OVR_DEBUG_LOG(("Failed 'CreateHIDFile' while opening device, error = 0x%X.",
                       ::GetLastError()));
        Device = 0;
        return false;
    }

    if (!HIDManager->HidD_SetNumInputBuffers(Device, 128))
    {
        OVR_ASSERT_LOG(false, ("Failed 'HidD_SetNumInputBuffers' while initializing device."));
        ::CloseHandle(Device);
        Device = 0;
        return false;
    }


    // Create a manual-reset non-signaled event.
    ReadOverlapped.hEvent = ::CreateEvent(0, TRUE, FALSE, 0);

    if (!ReadOverlapped.hEvent)
    {
        OVR_ASSERT_LOG(false, ("Failed to create event."));
        ::CloseHandle(Device);
        Device = 0;
        return false;
    }

    if (!initInfo())
    {
        OVR_ASSERT_LOG(false, ("Failed to get HIDDevice info."));

        ::CloseHandle(ReadOverlapped.hEvent);
        memset(&ReadOverlapped, 0, sizeof(OVERLAPPED));

        ::CloseHandle(Device);
        Device = 0;
        return false;
    }

    if (!initializeRead())
    {
        OVR_ASSERT_LOG(false, ("Failed to get intialize read for HIDDevice."));

        ::CloseHandle(ReadOverlapped.hEvent);
        memset(&ReadOverlapped, 0, sizeof(OVERLAPPED));

        ::CloseHandle(Device);
        Device = 0;
        return false;
    }

    return true;
}

int DeviceManagerThread::Run()
{
    ThreadCommand::PopBuffer command;

    SetThreadName("OVR::DeviceManagerThread");
    LogText("OVR::DeviceManagerThread - running (ThreadId=%p).\n", GetThreadId());
    

    while(!IsExiting())
    {
        // PopCommand will reset event on empty queue.
        if (PopCommand(&command))
        {
            command.Execute();
        }
        else
        {
            bool commands = 0;
            do
            {
                int n = poll(&PollFds[0], PollFds.GetSize(), -1);

                for (int i = 0; i < PollFds.GetSize(); i++)
                {
                    if (PollFds[i].revents & POLLERR)
                    {
                        OVR_DEBUG_LOG(("poll: error on [%d]: %d", i, PollFds[i].fd));
                    }
                    else if (PollFds[i].revents & POLLIN)
                    {
                        if (FdNotifiers[i])
                            FdNotifiers[i]->OnEvent(i, PollFds[i].fd);
                        else if (i == 0) // command
                        {
                            char dummy[128];                            
                            read(PollFds[i].fd, dummy, 128);
                            commands = 1;
                        }
                    }

                    if (PollFds[i].revents & POLLHUP)
                        PollFds[i].events = 0;

                    if (PollFds[i].revents != 0)
                    {
                        n--;
                        if (n == 0)
                            break;
                    }
                }                    
            } while (PollFds.GetSize() > 0 && !commands);
        }
    }

    LogText("OVR::DeviceManagerThread - exiting (ThreadId=%p).\n", GetThreadId());
    return 0;
}

bool HSWDisplay::Initialize(const ovrRenderAPIConfig* apiConfig)
{
    const ovrGLConfig* config = (const ovrGLConfig*)apiConfig;

    if(config)
    {
        // The following is essentially copied from CAPI_GL_DistortionRender.cpp's 
        // Initialize function. To do: Merge this to a central location.
        RenderParams.Multisample = config->OGL.Header.Multisample;
        RenderParams.RTSize      = config->OGL.Header.RTSize;

        #if defined(OVR_OS_WIN32)
            RenderParams.Window = (config->OGL.Window) ? config->OGL.Window : GetActiveWindow();
            RenderParams.DC     = config->OGL.DC;
        #elif defined(OVR_OS_LINUX)
            if (config->OGL.Disp)
                RenderParams.Disp = config->OGL.Disp;
            if (!RenderParams.Disp)
                RenderParams.Disp = XOpenDisplay(NULL);
            if (!RenderParams.Disp)
            {
                OVR_DEBUG_LOG(("XOpenDisplay failed."));
                return false;
            }

            if (config->OGL.Win)
                RenderParams.Win= config->OGL.Win;
            if (!RenderParams.Win)
                RenderParams.Win = glXGetCurrentDrawable();

            if (!RenderParams.Win)
            {
                OVR_DEBUG_LOG(("XGetInputFocus failed."));
                return false;
            }
        #endif
    }
    else
    {
        UnloadGraphics();
    }

    return true;
}

void RefCountNTSImplCore::checkInvalidDelete(RefCountNTSImplCore *pmem)
{
#ifdef OVR_BUILD_DEBUG    
    if (pmem->RefCount != 0)
	{
		OVR_DEBUG_LOG( ("Invalid delete call on ref-counted object at %p. Please use Release()", pmem) );
		OVR_ASSERT(0);
	}
#else
	OVR_UNUSED( pmem );
#endif
}

// Initializes System core, installing allocator.
void System::Init(Log* log, Allocator *palloc)
{    
    if (!Allocator::GetInstance())
    {
        Log::SetGlobalLog(log);
        Allocator::setInstance(palloc);
    }
    else
    {
        OVR_DEBUG_LOG(("[System] Init failed - duplicate call."));
    }
}

UInt64 Timer::GetTicksNanos()
{
    // Choreographer vsync timestamp is based on.
    struct timespec tp;
    const int       status = clock_gettime(CLOCK_MONOTONIC, &tp);

    if (status != 0)
    {
        OVR_DEBUG_LOG(("clock_gettime status=%i", status ));
    }
    const UInt64 result = (UInt64)tp.tv_sec * (UInt64)(1000 * 1000 * 1000) + UInt64(tp.tv_nsec);
    return result;
}

void LatencyTest::BeginTest()
{
     if (State == State_WaitingForButton)
    {
        // Set color to black and wait a while.
        RenderColor = CALIBRATE_BLACK;

        State = State_WaitingForSettlePreCalibrationColorBlack;
        OVR_DEBUG_LOG(("State_WaitingForButton -> State_WaitingForSettlePreCalibrationColorBlack."));

        setTimer(TIME_TO_WAIT_FOR_SETTLE_PRE_CALIBRATION);
    }
}

// The actual first function called on thread start
unsigned WINAPI Thread_Win32StartFn(void * phandle)
{
    Thread *   pthread = (Thread*)phandle;
    if (pthread->Processor != -1)
    {
        DWORD_PTR ret = SetThreadAffinityMask(GetCurrentThread(), (DWORD)pthread->Processor);
        if (ret == 0)
            OVR_DEBUG_LOG(("Could not set hardware processor for the thread"));
    }
    BOOL ret = ::SetThreadPriority(GetCurrentThread(), Thread::GetOSPriority(pthread->Priority));
    if (ret == 0)
        OVR_DEBUG_LOG(("Could not set thread priority"));
    OVR_UNUSED(ret);

    // Ensure that ThreadId is assigned once thread is running, in case
    // beginthread hasn't filled it in yet.
    pthread->IdValue = (ThreadId)::GetCurrentThreadId();

    pthread->PRun();
    // Signal the thread as done and release it atomically.
    pthread->Finish();
    return 0;
}

UInt16 SelectSensorRampValue(const UInt16* ramp, unsigned count,
                                    float val, float factor, const char* label)
{    
    UInt16 threshold = (UInt16)(val * factor);

    for (unsigned i = 0; i<count; i++)
    {
        if (ramp[i] >= threshold)
            return ramp[i];
    }
    OVR_DEBUG_LOG(("SensorDevice::SetRange - %s clamped to %0.4f",
                   label, float(ramp[count-1]) / factor));
    OVR_UNUSED2(factor, label);
    return ramp[count-1];
}

HWND RenderFocusReader::ReadActiveWindow()
{
    FocusState = Reader.Get();
    if (!FocusState || NoSharedMemory)
    {
        if (!Reader.Open(OVR_FOCUS_OBSERVER_SHARE_NAME))
        {
            OVR_DEBUG_LOG(("[Win32ShimFunctions] Unable to open the shared memory space"));
            // Note: This should only warn and not assert because it is normal behavior when the server is not running.
            NoSharedMemory = true;
            return 0;
        }

        FocusState = Reader.Get();
        if (!FocusState)
        {
            OVR_DEBUG_LOG(("[Win32ShimFunctions] Unable to get the shared memory space"));
            NoSharedMemory = true;
            return 0;
        }
    }

    return (HWND)Ptr64ToPtr(FocusState->ActiveWindowHandle);
}

// Initializes System core, installing allocator.
void System::Init(Log* log, Allocator *palloc)
{    
    if (!Allocator::GetInstance())
    {
        Log::SetGlobalLog(log);
        Timer::initializeTimerSystem();
        Allocator::setInstance(palloc);
		Display::Initialize();
		DirectDisplayInitialize();
    }
    else
    {
        OVR_DEBUG_LOG(("System::Init failed - duplicate call."));
    }
}