SimpleCompute12.h

//--------------------------------------------------------------------------------------
// SimpleCompute12.h
//
// Advanced Technology Group (ATG)
// Copyright (C) Microsoft Corporation. All rights reserved.
//--------------------------------------------------------------------------------------

#pragma once

#include "DeviceResources.h"
#include "StepTimer.h"
#include "ControllerHelp.h"

class SmoothedFPS
{
public:
    SmoothedFPS(uint32_t frameInterval = 100)
    {
        Initialize(frameInterval);
    }

    void Initialize(uint32_t frameInterval = 100)
    {
        m_frameInterval = frameInterval;
        m_timeAccumulator = 0.0f;
        m_frameAccumulator = 0;
        m_smoothedFPS = 0.0f;
    }

    void Tick(float DeltaTime)
    {
        m_timeAccumulator += DeltaTime;
        ++m_frameAccumulator;

        if (m_frameAccumulator >= m_frameInterval)
        {
            m_smoothedFPS = (float)m_frameInterval / m_timeAccumulator;
            m_timeAccumulator = 0.0f;
            m_frameAccumulator = 0;
        }
    }

    float GetFPS() const { return m_smoothedFPS; }

private:
    float m_smoothedFPS;
    float m_timeAccumulator;
    uint32_t m_frameAccumulator;
    uint32_t m_frameInterval;
};

// A basic sample implementation that creates a D3D12 device and
// provides a render loop.
class Sample
{
public:

    Sample() noexcept(false);
    ~Sample() = default;

    Sample(Sample&&) = delete;
    Sample& operator= (Sample&&) = delete;

    Sample(Sample const&) = delete;
    Sample& operator= (Sample const&) = delete;

    // Initialization and management
    void Initialize(IUnknown* window);

    // Basic Sample loop
    void Tick();

    // Messages
    void OnSuspending();
    void OnResuming();

    // Properties
    bool RequestHDRMode() const noexcept { return m_deviceResources ? (m_deviceResources->GetDeviceOptions() & DX::DeviceResources::c_EnableHDR) != 0 : false; }

private:
    void Update(DX::StepTimer const& timer);
    void Render();

    void Clear();

    void CreateDeviceDependentResources();
    void CreateWindowSizeDependentResources();

    void ResetWindow();
    void UpdateFractalData();
        // called by compute side of work, updates the window parameters

    bool EnsureResourceState(_In_range_(0, 1) uint32_t index, D3D12_RESOURCE_STATES afterState);

    void AsyncComputeThreadProc();

    uint32_t ComputeIndex()  const { return 1 - m_renderIndex; }
    uint32_t RenderIndex() const { return m_renderIndex; }
    void SwapRenderComputeIndex() { m_renderIndex = 1 - m_renderIndex; }

    // Device resources.
    std::unique_ptr<DX::DeviceResources>				m_deviceResources;

    // Rendering loop timer.
    uint64_t											m_frame;
    DX::StepTimer										m_timer;

    // on-screen help
    std::unique_ptr<ATG::Help>                          m_help;
    bool                                                m_showHelp;

    // Input devices.
    std::unique_ptr<DirectX::GamePad>					m_gamePad;
    DirectX::GamePad::ButtonStateTracker				m_gamePadButtons;

    // Compute dat
    uint32_t                                            m_ThreadGroupX;
    uint32_t                                            m_ThreadGroupY;

    SmoothedFPS                                         m_renderFPS;
    SmoothedFPS                                         m_computeFPS;

    std::atomic<bool>                                   m_terminateThread;
    std::atomic<bool>                                   m_suspendThread;
    std::thread *                                       m_computeThread;

    std::atomic<uint32_t>                               m_renderIndex;              // which bank of fractal data the renderer is using, the value is either 0 or 1, compute is using the inverse

    DirectX::XMFLOAT4									m_window;                   // the bounds for the Mandelbrot set being calculated on the CPU
    uint32_t                                            m_fractalMaxIterations;	    // number of iterations when calculating the Mandelbrot set on the CPU
    std::atomic<bool>                                   m_windowUpdated;

    // shared data
    std::unique_ptr<DirectX::DescriptorHeap>            m_SRVDescriptorHeap;        // shader resource views for the fractal texture and data
    std::unique_ptr<DirectX::DescriptorHeap>            m_samplerDescriptorHeap;    // shader resource views for the samplers used by the compute shader
    DirectX::SharedGraphicsResource                     m_renderHeap;               // renderer version of the fractal constant data
    DirectX::SharedGraphicsResource                     m_computeHeap;              // async compute version of the fractal constant data

    // fractal texture data
    Microsoft::WRL::ComPtr<ID3D12Resource>              m_fractalColorMap[2];       // the textures used by the sampler for coloring the computed fractal, one for sync, one for async
    Microsoft::WRL::ComPtr<ID3D12Resource>              m_fractalTexture[2];        // the actual texture generated by the compute shader, double buffered, async and render operating on opposite textures
    D3D12_RESOURCE_STATES                               m_resourceStateFractalTexture[2];   // current state of the fractal texture, unordered or texture view
    Microsoft::WRL::ComPtr<ID3D12Fence>                 m_renderResourceFence;      // fence used by async compute to start once it's texture has changed to unordered access
    uint64_t                                            m_renderResourceFenceValue;

    // compute data
    std::atomic<bool>                                   m_usingAsyncCompute;

    Microsoft::WRL::ComPtr<ID3D12PipelineState>         m_computePSO;
    Microsoft::WRL::ComPtr<ID3D12RootSignature>         m_computeRootSignature;
    Microsoft::WRL::ComPtr<ID3D12CommandAllocator>      m_computeAllocator;
    Microsoft::WRL::ComPtr<ID3D12CommandQueue>          m_computeCommandQueue;
    Microsoft::WRL::ComPtr<ID3D12GraphicsCommandList>   m_computeCommandList;

    Microsoft::WRL::ComPtr<ID3D12Fence>                 m_computeFence;             // fence used by the async compute shader to stall waiting for task is complete, so it can signal render when it's done
    uint64_t                                            m_computeFenceValue;
    Microsoft::WRL::Wrappers::Event                     m_computeFenceEvent;

    Microsoft::WRL::Wrappers::Event                     m_computeResumeSignal;

    // DirectXTK objects.
    std::unique_ptr<DirectX::DescriptorHeap>            m_resourceDescriptors;
    std::unique_ptr<DirectX::SpriteBatch>               m_spriteBatch;
    std::unique_ptr<DirectX::GraphicsMemory>            m_graphicsMemory;
    std::unique_ptr<DirectX::SpriteFont>                m_font;
    std::unique_ptr<DirectX::SpriteFont>                m_ctrlFont;

    enum Descriptors
    {
        TextFont,
        ControllerFont,
        Count
    };

    enum ResourceBufferState : uint32_t
    {
        ResourceState_ReadyCompute,
        ResourceState_Computing,    // async is currently running on this resource buffer
        ResourceState_Computed,     // async buffer has been updated, no one is using it, moved to this state by async thread, only render will access in this state
        ResourceState_Switching,    // switching buffer from texture to unordered, from render to compute access
        ResourceState_Rendering,    // buffer is currently being used by the render system for the frame
        ResourceState_Rendered      // render frame finished for this resource. possible to switch to computing by render thread if needed
    };

    std::atomic<ResourceBufferState> m_resourceState[2];

    // Indexes for the root parameter table
    enum RootParameters : uint32_t
    {
        e_rootParameterCB = 0,
        e_rootParameterSampler,
        e_rootParameterSRV,
        e_rootParameterUAV,
        e_numRootParameters
    };

    // indexes of resources into the descriptor heap
    enum DescriptorHeapCount : uint32_t
    {
        e_cCB = 10,
        e_cUAV = 2,
        e_cSRV = 4,
    };
    enum DescriptorHeapIndex : uint32_t
    {
        e_iCB = 0,
        e_iUAV = e_iCB + e_cCB,
        e_iSRV = e_iUAV + e_cUAV,
        e_iHeapEnd = e_iSRV + e_cSRV
    };
};