Moved Native App from master repository

4 files changed, 641 insertions, 0 deletions

diff --git a/NativeApp/src/UWP/Common/DeviceResources.cpp b/NativeApp/src/UWP/Common/DeviceResources.cpp
new file mode 100644
index 0000000..c111a54
--- /dev/null
+++ b/NativeApp/src/UWP/Common/DeviceResources.cpp
@@ -0,0 +1,328 @@
+
+#define NOMINIMAX
+#include <wrl.h>
+#include <wrl/client.h>
+#include <DirectXMath.h>
+#include <agile.h>
+
+#include <dxgi1_4.h>
+#include <d3d12.h>
+#include <d3d11.h>
+#include <pix.h>
+
+#if defined(_DEBUG)
+#   include <dxgidebug.h>
+#endif
+
+#include "DeviceResources.h"
+#include "DirectXHelper.h"
+
+
+using namespace DirectX;
+using namespace Microsoft::WRL;
+using namespace Windows::Foundation;
+using namespace Windows::Graphics::Display;
+using namespace Windows::UI::Core;
+using namespace Windows::UI::Xaml::Controls;
+using namespace Platform;
+
+namespace DisplayMetrics
+{
+    // High resolution displays can require a lot of GPU and battery power to render.
+    // High resolution phones, for example, may suffer from poor battery life if
+    // games attempt to render at 60 frames per second at full fidelity.
+    // The decision to render at full fidelity across all platforms and form factors
+    // should be deliberate.
+    static const bool SupportHighResolutions = false;
+
+    // The default thresholds that define a "high resolution" display. If the thresholds
+    // are exceeded and SupportHighResolutions is false, the dimensions will be scaled
+    // by 50%.
+    static const float DpiThreshold = 192.0f;		// 200% of standard desktop display.
+    static const float WidthThreshold = 1920.0f;	// 1080p width.
+    static const float HeightThreshold = 1080.0f;	// 1080p height.
+};
+
+// Constants used to calculate screen rotations.
+namespace ScreenRotation
+{
+    // 0-degree Z-rotation
+    static const XMFLOAT4X4 Rotation0(
+        1.0f, 0.0f, 0.0f, 0.0f,
+        0.0f, 1.0f, 0.0f, 0.0f,
+        0.0f, 0.0f, 1.0f, 0.0f,
+        0.0f, 0.0f, 0.0f, 1.0f
+        );
+
+    // 90-degree Z-rotation
+    static const XMFLOAT4X4 Rotation90(
+        0.0f, 1.0f, 0.0f, 0.0f,
+        -1.0f, 0.0f, 0.0f, 0.0f,
+        0.0f, 0.0f, 1.0f, 0.0f,
+        0.0f, 0.0f, 0.0f, 1.0f
+        );
+
+    // 180-degree Z-rotation
+    static const XMFLOAT4X4 Rotation180(
+        -1.0f, 0.0f, 0.0f, 0.0f,
+        0.0f, -1.0f, 0.0f, 0.0f,
+        0.0f, 0.0f, 1.0f, 0.0f,
+        0.0f, 0.0f, 0.0f, 1.0f
+        );
+
+    // 270-degree Z-rotation
+    static const XMFLOAT4X4 Rotation270(
+        0.0f, -1.0f, 0.0f, 0.0f,
+        1.0f, 0.0f, 0.0f, 0.0f,
+        0.0f, 0.0f, 1.0f, 0.0f,
+        0.0f, 0.0f, 0.0f, 1.0f
+        );
+};
+
+// Constructor for DeviceResources.
+DX::DeviceResources::DeviceResources(ID3D11Device *d3d11Device, ID3D12Device *d3d12Device) :
+    m_d3dRenderTargetSize(),
+    m_outputSize(),
+    m_logicalSize(),
+    m_nativeOrientation(DisplayOrientations::None),
+    m_currentOrientation(DisplayOrientations::None),
+    m_dpi(-1.0f),
+    m_deviceRemoved(false),
+    m_d3d11Device(d3d11Device),
+    m_d3d12Device(d3d12Device)
+{
+}
+
+
+void DX::DeviceResources::SetSwapChainRotation(IDXGISwapChain3 *swapChain)
+{
+    // Set the proper orientation for the swap chain, and generate
+    // 3D matrix transformations for rendering to the rotated swap chain.
+    // The 3D matrix is specified explicitly to avoid rounding errors.
+    DXGI_MODE_ROTATION displayRotation = ComputeDisplayRotation();
+    switch (displayRotation)
+    {
+    case DXGI_MODE_ROTATION_IDENTITY:
+        m_orientationTransform3D = ScreenRotation::Rotation0;
+        break;
+
+    case DXGI_MODE_ROTATION_ROTATE90:
+        m_orientationTransform3D = ScreenRotation::Rotation270;
+        break;
+
+    case DXGI_MODE_ROTATION_ROTATE180:
+        m_orientationTransform3D = ScreenRotation::Rotation180;
+        break;
+
+    case DXGI_MODE_ROTATION_ROTATE270:
+        m_orientationTransform3D = ScreenRotation::Rotation90;
+        break;
+
+    default:
+        throw ref new FailureException();
+    }
+
+    DX::ThrowIfFailed(
+        swapChain->SetRotation(displayRotation)
+    );
+}
+
+// Determine the dimensions of the render target and whether it will be scaled down.
+void DX::DeviceResources::UpdateRenderTargetSize()
+{
+    m_effectiveDpi = m_dpi;
+
+    // To improve battery life on high resolution devices, render to a smaller render target
+    // and allow the GPU to scale the output when it is presented.
+    if (!DisplayMetrics::SupportHighResolutions && m_dpi > DisplayMetrics::DpiThreshold)
+    {
+        float width = DX::ConvertDipsToPixels(m_logicalSize.Width, m_dpi);
+        float height = DX::ConvertDipsToPixels(m_logicalSize.Height, m_dpi);
+
+        // When the device is in portrait orientation, height > width. Compare the
+        // larger dimension against the width threshold and the smaller dimension
+        // against the height threshold.
+        if (max(width, height) > DisplayMetrics::WidthThreshold && min(width, height) > DisplayMetrics::HeightThreshold)
+        {
+            // To scale the app we change the effective DPI. Logical size does not change.
+            m_effectiveDpi /= 2.0f;
+        }
+    }
+
+    // Calculate the necessary render target size in pixels.
+    m_outputSize.Width = DX::ConvertDipsToPixels(m_logicalSize.Width, m_effectiveDpi);
+    m_outputSize.Height = DX::ConvertDipsToPixels(m_logicalSize.Height, m_effectiveDpi);
+
+    // Prevent zero size DirectX content from being created.
+    m_outputSize.Width = max(m_outputSize.Width, 1);
+    m_outputSize.Height = max(m_outputSize.Height, 1);
+
+
+    // The width and height of the swap chain must be based on the window's
+    // natively-oriented width and height. If the window is not in the native
+    // orientation, the dimensions must be reversed.
+    DXGI_MODE_ROTATION displayRotation = ComputeDisplayRotation();
+
+    bool swapDimensions = displayRotation == DXGI_MODE_ROTATION_ROTATE90 || displayRotation == DXGI_MODE_ROTATION_ROTATE270;
+    auto fWidth = swapDimensions ? m_outputSize.Height : m_outputSize.Width;
+    auto fHeight = swapDimensions ? m_outputSize.Width : m_outputSize.Height;
+
+    m_backBufferWidth = lround(fWidth);
+    m_backBufferHeight = lround(fHeight);
+}
+
+// This method is called when the CoreWindow is created (or re-created).
+void DX::DeviceResources::SetWindow(CoreWindow^ window)
+{
+    DisplayInformation^ currentDisplayInformation = DisplayInformation::GetForCurrentView();
+
+    m_window = window;
+    m_logicalSize = Windows::Foundation::Size(window->Bounds.Width, window->Bounds.Height);
+    m_nativeOrientation = currentDisplayInformation->NativeOrientation;
+    m_currentOrientation = currentDisplayInformation->CurrentOrientation;
+    m_dpi = currentDisplayInformation->LogicalDpi;
+
+    //CreateWindowSizeDependentResources();
+}
+
+// This method is called in the event handler for the SizeChanged event.
+void DX::DeviceResources::SetLogicalSize(Windows::Foundation::Size logicalSize)
+{
+    if (m_logicalSize != logicalSize)
+    {
+        m_logicalSize = logicalSize;
+        //CreateWindowSizeDependentResources();
+    }
+}
+
+// This method is called in the event handler for the DpiChanged event.
+void DX::DeviceResources::SetDpi(float dpi)
+{
+    if (dpi != m_dpi)
+    {
+        m_dpi = dpi;
+
+        // When the display DPI changes, the logical size of the window (measured in Dips) also changes and needs to be updated.
+        m_logicalSize = Windows::Foundation::Size(m_window->Bounds.Width, m_window->Bounds.Height);
+
+        //CreateWindowSizeDependentResources();
+    }
+}
+
+// This method is called in the event handler for the OrientationChanged event.
+void DX::DeviceResources::SetCurrentOrientation(DisplayOrientations currentOrientation)
+{
+    if (m_currentOrientation != currentOrientation)
+    {
+        m_currentOrientation = currentOrientation;
+        //CreateWindowSizeDependentResources();
+    }
+}
+
+// This method is called in the event handler for the DisplayContentsInvalidated event.
+void DX::DeviceResources::ValidateDevice()
+{
+    // The D3D Device is no longer valid if the default adapter changed since the device
+    // was created or if the device has been removed.
+
+    ComPtr<IDXGIDevice3> dxgiDevice;
+    if(m_d3d11Device)
+        DX::ThrowIfFailed(m_d3d11Device.As(&dxgiDevice));
+    else if(m_d3d12Device)
+        DX::ThrowIfFailed(m_d3d12Device.As(&dxgiDevice));
+
+    ComPtr<IDXGIAdapter> deviceAdapter;
+    DX::ThrowIfFailed(dxgiDevice->GetAdapter(&deviceAdapter));
+
+    ComPtr<IDXGIFactory2> deviceFactory;
+    DX::ThrowIfFailed(deviceAdapter->GetParent(IID_PPV_ARGS(&deviceFactory)));
+
+    // First, get the LUID for the default adapter from when the device was created.
+
+    DXGI_ADAPTER_DESC previousDesc;
+    {
+        ComPtr<IDXGIAdapter1> previousDefaultAdapter;
+        DX::ThrowIfFailed(deviceFactory->EnumAdapters1(0, &previousDefaultAdapter));
+
+        DX::ThrowIfFailed(previousDefaultAdapter->GetDesc(&previousDesc));
+    }
+
+    // Next, get the information for the current default adapter.
+
+    DXGI_ADAPTER_DESC currentDesc;
+    {
+        ComPtr<IDXGIFactory4> currentDxgiFactory;
+        DX::ThrowIfFailed(CreateDXGIFactory1(IID_PPV_ARGS(&currentDxgiFactory)));
+
+        ComPtr<IDXGIAdapter1> currentDefaultAdapter;
+        DX::ThrowIfFailed(currentDxgiFactory->EnumAdapters1(0, &currentDefaultAdapter));
+
+        DX::ThrowIfFailed(currentDefaultAdapter->GetDesc(&currentDesc));
+    }
+
+    // If the adapter LUIDs don't match, or if the device reports that it has been removed,
+    // a new D3D device must be created.
+
+    if (previousDesc.AdapterLuid.LowPart != currentDesc.AdapterLuid.LowPart ||
+        previousDesc.AdapterLuid.HighPart != currentDesc.AdapterLuid.HighPart ||
+        m_d3d11Device && FAILED(m_d3d11Device->GetDeviceRemovedReason()) || 
+        m_d3d12Device && FAILED(m_d3d12Device->GetDeviceRemovedReason()))
+    {
+        m_deviceRemoved = true;
+    }
+}
+
+// This method determines the rotation between the display device's native Orientation and the
+// current display orientation.
+DXGI_MODE_ROTATION DX::DeviceResources::ComputeDisplayRotation()
+{
+    DXGI_MODE_ROTATION rotation = DXGI_MODE_ROTATION_UNSPECIFIED;
+
+    // Note: NativeOrientation can only be Landscape or Portrait even though
+    // the DisplayOrientations enum has other values.
+    switch (m_nativeOrientation)
+    {
+    case DisplayOrientations::Landscape:
+        switch (m_currentOrientation)
+        {
+        case DisplayOrientations::Landscape:
+            rotation = DXGI_MODE_ROTATION_IDENTITY;
+            break;
+
+        case DisplayOrientations::Portrait:
+            rotation = DXGI_MODE_ROTATION_ROTATE270;
+            break;
+
+        case DisplayOrientations::LandscapeFlipped:
+            rotation = DXGI_MODE_ROTATION_ROTATE180;
+            break;
+
+        case DisplayOrientations::PortraitFlipped:
+            rotation = DXGI_MODE_ROTATION_ROTATE90;
+            break;
+        }
+        break;
+
+    case DisplayOrientations::Portrait:
+        switch (m_currentOrientation)
+        {
+        case DisplayOrientations::Landscape:
+            rotation = DXGI_MODE_ROTATION_ROTATE90;
+            break;
+
+        case DisplayOrientations::Portrait:
+            rotation = DXGI_MODE_ROTATION_IDENTITY;
+            break;
+
+        case DisplayOrientations::LandscapeFlipped:
+            rotation = DXGI_MODE_ROTATION_ROTATE270;
+            break;
+
+        case DisplayOrientations::PortraitFlipped:
+            rotation = DXGI_MODE_ROTATION_ROTATE180;
+            break;
+        }
+        break;
+    }
+    return rotation;
+}
diff --git a/NativeApp/src/UWP/Common/DeviceResources.h b/NativeApp/src/UWP/Common/DeviceResources.h
new file mode 100644
index 0000000..69fa00c
--- /dev/null
+++ b/NativeApp/src/UWP/Common/DeviceResources.h
@@ -0,0 +1,72 @@
+#pragma once
+
+#include <dxgi1_4.h>
+#include <d3d12.h>
+#include <d3d11.h>
+#include <DirectXMath.h>
+#include <agile.h>
+
+namespace DX
+{
+    // Controls all the DirectX device resources.
+    class DeviceResources
+    {
+    public:
+        DeviceResources(ID3D11Device *d3d11Device, ID3D12Device *d3d12Device);
+
+        void SetWindow(Windows::UI::Core::CoreWindow^ window);
+        void SetLogicalSize(Windows::Foundation::Size logicalSize);
+        void SetCurrentOrientation(Windows::Graphics::Display::DisplayOrientations currentOrientation);
+        void SetDpi(float dpi);
+        void ValidateDevice();
+        void SetSwapChainRotation(IDXGISwapChain3 *swapChain);
+
+        // The size of the render target, in pixels.
+        Windows::Foundation::Size	GetOutputSize() const				{ return m_outputSize; }
+
+        // The size of the render target, in dips.
+        Windows::Foundation::Size	GetLogicalSize() const				{ return m_logicalSize; }
+
+        float						GetDpi() const						{ return m_effectiveDpi; }
+        bool						IsDeviceRemoved() const				{ return m_deviceRemoved; }
+
+        // D3D Accessors.
+        DirectX::XMFLOAT4X4			GetOrientationTransform3D() const	{ return m_orientationTransform3D; }
+
+        void UpdateRenderTargetSize();
+        UINT GetBackBufferWidth()  {return m_backBufferWidth;}
+        UINT GetBackBufferHeight() {return m_backBufferHeight;}
+
+        Windows::UI::Core::CoreWindow^ GetWindow(){return m_window.Get();}
+
+    private:
+        
+        
+        DXGI_MODE_ROTATION ComputeDisplayRotation();
+
+        bool											m_deviceRemoved;
+
+        // Direct3D objects.
+        Microsoft::WRL::ComPtr<ID3D12Device>			m_d3d12Device;
+        Microsoft::WRL::ComPtr<ID3D11Device>			m_d3d11Device;
+        
+        // Cached reference to the Window.
+        Platform::Agile<Windows::UI::Core::CoreWindow>	m_window;
+
+        // Cached device properties.
+        Windows::Foundation::Size						m_d3dRenderTargetSize;
+        Windows::Foundation::Size						m_outputSize;
+        Windows::Foundation::Size						m_logicalSize;
+        Windows::Graphics::Display::DisplayOrientations	m_nativeOrientation;
+        Windows::Graphics::Display::DisplayOrientations	m_currentOrientation;
+        float											m_dpi;
+        UINT                                            m_backBufferWidth  = 0;
+        UINT                                            m_backBufferHeight = 0;
+
+        // This is the DPI that will be reported back to the app. It takes into account whether the app supports high resolution screens or not.
+        float											m_effectiveDpi;
+
+        // Transforms used for display orientation.
+        DirectX::XMFLOAT4X4								m_orientationTransform3D;
+    };
+}
diff --git a/NativeApp/src/UWP/Common/DirectXHelper.h b/NativeApp/src/UWP/Common/DirectXHelper.h
new file mode 100644
index 0000000..7bfe36f
--- /dev/null
+++ b/NativeApp/src/UWP/Common/DirectXHelper.h
@@ -0,0 +1,58 @@
+#pragma once
+
+#include <ppltasks.h>	// For create_task
+
+namespace DX
+{
+    inline void ThrowIfFailed(HRESULT hr)
+    {
+        if (FAILED(hr))
+        {
+            // Set a breakpoint on this line to catch Win32 API errors.
+            throw Platform::Exception::CreateException(hr);
+        }
+    }
+
+    // Function that reads from a binary file asynchronously.
+    inline Concurrency::task<std::vector<byte>> ReadDataAsync(const std::wstring& filename)
+    {
+        using namespace Windows::Storage;
+        using namespace Concurrency;
+
+        auto folder = Windows::ApplicationModel::Package::Current->InstalledLocation;
+
+        return create_task(folder->GetFileAsync(Platform::StringReference(filename.c_str()))).then([](StorageFile^ file)
+        {
+            return FileIO::ReadBufferAsync(file);
+        }).then([](Streams::IBuffer^ fileBuffer) -> std::vector<byte>
+        {
+            std::vector<byte> returnBuffer;
+            returnBuffer.resize(fileBuffer->Length);
+            Streams::DataReader::FromBuffer(fileBuffer)->ReadBytes(Platform::ArrayReference<byte>(returnBuffer.data(), fileBuffer->Length));
+            return returnBuffer;
+        });
+    }
+
+    // Converts a length in device-independent pixels (DIPs) to a length in physical pixels.
+    inline float ConvertDipsToPixels(float dips, float dpi)
+    {
+        static const float dipsPerInch = 96.0f;
+        return floorf(dips * dpi / dipsPerInch + 0.5f); // Round to nearest integer.
+    }
+
+    // Assign a name to the object to aid with debugging.
+#if defined(_DEBUG)
+    inline void SetName(ID3D12Object* pObject, LPCWSTR name)
+    {
+        pObject->SetName(name);
+    }
+#else
+    inline void SetName(ID3D12Object*, LPCWSTR)
+    {
+    }
+#endif
+}
+
+// Naming helper function for ComPtr<T>.
+// Assigns the name of the variable as the name of the object.
+#define NAME_D3D12_OBJECT(x) DX::SetName(x.Get(), L#x)
diff --git a/NativeApp/src/UWP/Common/StepTimer.h b/NativeApp/src/UWP/Common/StepTimer.h
new file mode 100644
index 0000000..c8addbc
--- /dev/null
+++ b/NativeApp/src/UWP/Common/StepTimer.h
@@ -0,0 +1,183 @@
+#pragma once
+
+#include <wrl.h>
+
+namespace DX
+{
+    // Helper class for animation and simulation timing.
+    class StepTimer
+    {
+    public:
+        StepTimer() : 
+            m_elapsedTicks(0),
+            m_totalTicks(0),
+            m_leftOverTicks(0),
+            m_frameCount(0),
+            m_framesPerSecond(0),
+            m_framesThisSecond(0),
+            m_qpcSecondCounter(0),
+            m_isFixedTimeStep(false),
+            m_targetElapsedTicks(TicksPerSecond / 60)
+        {
+            if (!QueryPerformanceFrequency(&m_qpcFrequency))
+            {
+                throw ref new Platform::FailureException();
+            }
+
+            if (!QueryPerformanceCounter(&m_qpcLastTime))
+            {
+                throw ref new Platform::FailureException();
+            }
+
+            // Initialize max delta to 1/10 of a second.
+            m_qpcMaxDelta = m_qpcFrequency.QuadPart / 10;
+        }
+
+        // Get elapsed time since the previous Update call.
+        uint64 GetElapsedTicks() const						{ return m_elapsedTicks; }
+        double GetElapsedSeconds() const					{ return TicksToSeconds(m_elapsedTicks); }
+
+        // Get total time since the start of the program.
+        uint64 GetTotalTicks() const						{ return m_totalTicks; }
+        double GetTotalSeconds() const						{ return TicksToSeconds(m_totalTicks); }
+
+        // Get total number of updates since start of the program.
+        uint32 GetFrameCount() const						{ return m_frameCount; }
+
+        // Get the current framerate.
+        uint32 GetFramesPerSecond() const					{ return m_framesPerSecond; }
+
+        // Set whether to use fixed or variable timestep mode.
+        void SetFixedTimeStep(bool isFixedTimestep)			{ m_isFixedTimeStep = isFixedTimestep; }
+
+        // Set how often to call Update when in fixed timestep mode.
+        void SetTargetElapsedTicks(uint64 targetElapsed)	{ m_targetElapsedTicks = targetElapsed; }
+        void SetTargetElapsedSeconds(double targetElapsed)	{ m_targetElapsedTicks = SecondsToTicks(targetElapsed); }
+
+        // Integer format represents time using 10,000,000 ticks per second.
+        static const uint64 TicksPerSecond = 10000000;
+
+        static double TicksToSeconds(uint64 ticks)			{ return static_cast<double>(ticks) / TicksPerSecond; }
+        static uint64 SecondsToTicks(double seconds)		{ return static_cast<uint64>(seconds * TicksPerSecond); }
+
+        // After an intentional timing discontinuity (for instance a blocking IO operation)
+        // call this to avoid having the fixed timestep logic attempt a set of catch-up 
+        // Update calls.
+
+        void ResetElapsedTime()
+        {
+            if (!QueryPerformanceCounter(&m_qpcLastTime))
+            {
+                throw ref new Platform::FailureException();
+            }
+
+            m_leftOverTicks = 0;
+            m_framesPerSecond = 0;
+            m_framesThisSecond = 0;
+            m_qpcSecondCounter = 0;
+        }
+
+        // Update timer state, calling the specified Update function the appropriate number of times.
+        template<typename TUpdate>
+        void Tick(const TUpdate& update)
+        {
+            // Query the current time.
+            LARGE_INTEGER currentTime;
+
+            if (!QueryPerformanceCounter(&currentTime))
+            {
+                throw ref new Platform::FailureException();
+            }
+
+            uint64 timeDelta = currentTime.QuadPart - m_qpcLastTime.QuadPart;
+
+            m_qpcLastTime = currentTime;
+            m_qpcSecondCounter += timeDelta;
+
+            // Clamp excessively large time deltas (e.g. after paused in the debugger).
+            if (timeDelta > m_qpcMaxDelta)
+            {
+                timeDelta = m_qpcMaxDelta;
+            }
+
+            // Convert QPC units into a canonical tick format. This cannot overflow due to the previous clamp.
+            timeDelta *= TicksPerSecond;
+            timeDelta /= m_qpcFrequency.QuadPart;
+
+            uint32 lastFrameCount = m_frameCount;
+
+            if (m_isFixedTimeStep)
+            {
+                // Fixed timestep update logic
+
+                // If the app is running very close to the target elapsed time (within 1/4 of a millisecond) just clamp
+                // the clock to exactly match the target value. This prevents tiny and irrelevant errors
+                // from accumulating over time. Without this clamping, a game that requested a 60 fps
+                // fixed update, running with vsync enabled on a 59.94 NTSC display, would eventually
+                // accumulate enough tiny errors that it would drop a frame. It is better to just round 
+                // small deviations down to zero to leave things running smoothly.
+
+                if (abs(static_cast<int64>(timeDelta - m_targetElapsedTicks)) < TicksPerSecond / 4000)
+                {
+                    timeDelta = m_targetElapsedTicks;
+                }
+
+                m_leftOverTicks += timeDelta;
+
+                while (m_leftOverTicks >= m_targetElapsedTicks)
+                {
+                    m_elapsedTicks = m_targetElapsedTicks;
+                    m_totalTicks += m_targetElapsedTicks;
+                    m_leftOverTicks -= m_targetElapsedTicks;
+                    m_frameCount++;
+
+                    update();
+                }
+            }
+            else
+            {
+                // Variable timestep update logic.
+                m_elapsedTicks = timeDelta;
+                m_totalTicks += timeDelta;
+                m_leftOverTicks = 0;
+                m_frameCount++;
+
+                update();
+            }
+
+            // Track the current framerate.
+            if (m_frameCount != lastFrameCount)
+            {
+                m_framesThisSecond++;
+            }
+
+            if (m_qpcSecondCounter >= static_cast<uint64>(m_qpcFrequency.QuadPart))
+            {
+                m_framesPerSecond = m_framesThisSecond;
+                m_framesThisSecond = 0;
+                m_qpcSecondCounter %= m_qpcFrequency.QuadPart;
+            }
+        }
+
+    private:
+        // Source timing data uses QPC units.
+        LARGE_INTEGER m_qpcFrequency;
+        LARGE_INTEGER m_qpcLastTime;
+        uint64 m_qpcMaxDelta;
+
+        // Derived timing data uses a canonical tick format.
+        uint64 m_elapsedTicks;
+        uint64 m_totalTicks;
+        uint64 m_leftOverTicks;
+
+        // Members for tracking the framerate.
+        uint32 m_frameCount;
+        uint32 m_framesPerSecond;
+        uint32 m_framesThisSecond;
+        uint64 m_qpcSecondCounter;
+
+        // Members for configuring fixed timestep mode.
+        bool m_isFixedTimeStep;
+        uint64 m_targetElapsedTicks;
+    };
+}