Introduction to 3D Game …ogramming with DirectX 12/Introduction-to-3D-Game-Programming-with-DirectX-12.ISO/Code.Textures/Chapter 16 Instancing and Frustum Culling/InstancingAndCulling/InstancingAndCullingApp.cpp

C/C++ Source or Header | 2016-03-02 | 35.7 KB | 1,022 lines

//***************************************************************************************
// InstancingAndCullingApp.cpp by Frank Luna (C) 2015 All Rights Reserved.
//***************************************************************************************

#include "../../Common/d3dApp.h"
#include "../../Common/MathHelper.h"
#include "../../Common/UploadBuffer.h"
#include "../../Common/GeometryGenerator.h"
#include "../../Common/Camera.h"
#include "FrameResource.h"

using Microsoft::WRL::ComPtr;
using namespace DirectX;
using namespace DirectX::PackedVector;

#pragma comment(lib, "d3dcompiler.lib")
#pragma comment(lib, "D3D12.lib")

const int gNumFrameResources = 3;

// Lightweight structure stores parameters to draw a shape.  This will
// vary from app-to-app.
struct RenderItem
{
    RenderItem() = default;
    RenderItem(const RenderItem& rhs) = delete;

    // World matrix of the shape that describes the object's local space
    // relative to the world space, which defines the position, orientation,
    // and scale of the object in the world.
    XMFLOAT4X4 World = MathHelper::Identity4x4();

    XMFLOAT4X4 TexTransform = MathHelper::Identity4x4();

    // Dirty flag indicating the object data has changed and we need to update the constant buffer.
    // Because we have an object cbuffer for each FrameResource, we have to apply the
    // update to each FrameResource.  Thus, when we modify obect data we should set
    // NumFramesDirty = gNumFrameResources so that each frame resource gets the update.
    int NumFramesDirty = gNumFrameResources;

    // Index into GPU constant buffer corresponding to the ObjectCB for this render item.
    UINT ObjCBIndex = -1;

    Material* Mat = nullptr;
    MeshGeometry* Geo = nullptr;

    // Primitive topology.
    D3D12_PRIMITIVE_TOPOLOGY PrimitiveType = D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST;

    BoundingBox Bounds;
    std::vector<InstanceData> Instances;

    // DrawIndexedInstanced parameters.
    UINT IndexCount = 0;
    UINT InstanceCount = 0;
    UINT StartIndexLocation = 0;
    int BaseVertexLocation = 0;
};

class InstancingAndCullingApp : public D3DApp
{
public:
    InstancingAndCullingApp(HINSTANCE hInstance);
    InstancingAndCullingApp(const InstancingAndCullingApp& rhs) = delete;
    InstancingAndCullingApp& operator=(const InstancingAndCullingApp& rhs) = delete;
    ~InstancingAndCullingApp();

    virtual bool Initialize()override;

private:
    virtual void OnResize()override;
    virtual void Update(const GameTimer& gt)override;
    virtual void Draw(const GameTimer& gt)override;

    virtual void OnMouseDown(WPARAM btnState, int x, int y)override;
    virtual void OnMouseUp(WPARAM btnState, int x, int y)override;
    virtual void OnMouseMove(WPARAM btnState, int x, int y)override;

    void OnKeyboardInput(const GameTimer& gt);
    void AnimateMaterials(const GameTimer& gt);
    void UpdateInstanceData(const GameTimer& gt);
    void UpdateMaterialBuffer(const GameTimer& gt);
    void UpdateMainPassCB(const GameTimer& gt);

    void LoadTextures();
    void BuildRootSignature();
    void BuildDescriptorHeaps();
    void BuildShadersAndInputLayout();
    void BuildSkullGeometry();
    void BuildPSOs();
    void BuildFrameResources();
    void BuildMaterials();
    void BuildRenderItems();
    void DrawRenderItems(ID3D12GraphicsCommandList* cmdList, const std::vector<RenderItem*>& ritems);

    std::array<const CD3DX12_STATIC_SAMPLER_DESC, 6> GetStaticSamplers();

private:

    std::vector<std::unique_ptr<FrameResource>> mFrameResources;
    FrameResource* mCurrFrameResource = nullptr;
    int mCurrFrameResourceIndex = 0;

    UINT mCbvSrvDescriptorSize = 0;

    ComPtr<ID3D12RootSignature> mRootSignature = nullptr;

    ComPtr<ID3D12DescriptorHeap> mSrvDescriptorHeap = nullptr;

    std::unordered_map<std::string, std::unique_ptr<MeshGeometry>> mGeometries;
    std::unordered_map<std::string, std::unique_ptr<Material>> mMaterials;
    std::unordered_map<std::string, std::unique_ptr<Texture>> mTextures;
    std::unordered_map<std::string, ComPtr<ID3DBlob>> mShaders;
    std::unordered_map<std::string, ComPtr<ID3D12PipelineState>> mPSOs;

    std::vector<D3D12_INPUT_ELEMENT_DESC> mInputLayout;

    // List of all the render items.
    std::vector<std::unique_ptr<RenderItem>> mAllRitems;

    // Render items divided by PSO.
    std::vector<RenderItem*> mOpaqueRitems;

    bool mFrustumCullingEnabled = true;

    BoundingFrustum mCamFrustum;

    PassConstants mMainPassCB;

    Camera mCamera;

    POINT mLastMousePos;
};

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE prevInstance,
    PSTR cmdLine, int showCmd)
{
    // Enable run-time memory check for debug builds.
#if defined(DEBUG) | defined(_DEBUG)
    _CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF);
#endif

    try
    {
        InstancingAndCullingApp theApp(hInstance);
        if(!theApp.Initialize())
            return 0;

        return theApp.Run();
    }
    catch(DxException& e)
    {
        MessageBox(nullptr, e.ToString().c_str(), L"HR Failed", MB_OK);
        return 0;
    }
}

InstancingAndCullingApp::InstancingAndCullingApp(HINSTANCE hInstance)
    : D3DApp(hInstance)
{
}

InstancingAndCullingApp::~InstancingAndCullingApp()
{
    if(md3dDevice != nullptr)
        FlushCommandQueue();
}

bool InstancingAndCullingApp::Initialize()
{
    if(!D3DApp::Initialize())
        return false;

    // Reset the command list to prep for initialization commands.
    ThrowIfFailed(mCommandList->Reset(mDirectCmdListAlloc.Get(), nullptr));

    // Get the increment size of a descriptor in this heap type.  This is hardware specific,
    // so we have to query this information.
    mCbvSrvDescriptorSize = md3dDevice->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);

    mCamera.SetPosition(0.0f, 2.0f, -15.0f);

    LoadTextures();
    BuildRootSignature();
    BuildDescriptorHeaps();
    BuildShadersAndInputLayout();
    BuildSkullGeometry();
    BuildMaterials();
    BuildRenderItems();
    BuildFrameResources();
    BuildPSOs();

    // Execute the initialization commands.
    ThrowIfFailed(mCommandList->Close());
    ID3D12CommandList* cmdsLists[] = { mCommandList.Get() };
    mCommandQueue->ExecuteCommandLists(_countof(cmdsLists), cmdsLists);

    // Wait until initialization is complete.
    FlushCommandQueue();

    return true;
}

void InstancingAndCullingApp::OnResize()
{
    D3DApp::OnResize();

    mCamera.SetLens(0.25f*MathHelper::Pi, AspectRatio(), 1.0f, 1000.0f);

    BoundingFrustum::CreateFromMatrix(mCamFrustum, mCamera.GetProj());
}

void InstancingAndCullingApp::Update(const GameTimer& gt)
{
    OnKeyboardInput(gt);

    // Cycle through the circular frame resource array.
    mCurrFrameResourceIndex = (mCurrFrameResourceIndex + 1) % gNumFrameResources;
    mCurrFrameResource = mFrameResources[mCurrFrameResourceIndex].get();

    // Has the GPU finished processing the commands of the current frame resource?
    // If not, wait until the GPU has completed commands up to this fence point.
    if(mCurrFrameResource->Fence != 0 && mFence->GetCompletedValue() < mCurrFrameResource->Fence)
    {
        HANDLE eventHandle = CreateEventEx(nullptr, false, false, EVENT_ALL_ACCESS);
        ThrowIfFailed(mFence->SetEventOnCompletion(mCurrFrameResource->Fence, eventHandle));
        WaitForSingleObject(eventHandle, INFINITE);
        CloseHandle(eventHandle);
    }

    AnimateMaterials(gt);
    UpdateInstanceData(gt);
    UpdateMaterialBuffer(gt);
    UpdateMainPassCB(gt);
}

void InstancingAndCullingApp::Draw(const GameTimer& gt)
{
    auto cmdListAlloc = mCurrFrameResource->CmdListAlloc;

    // Reuse the memory associated with command recording.
    // We can only reset when the associated command lists have finished execution on the GPU.
    ThrowIfFailed(cmdListAlloc->Reset());

    // A command list can be reset after it has been added to the command queue via ExecuteCommandList.
    // Reusing the command list reuses memory.
    ThrowIfFailed(mCommandList->Reset(cmdListAlloc.Get(), mPSOs["opaque"].Get()));

    mCommandList->RSSetViewports(1, &mScreenViewport);
    mCommandList->RSSetScissorRects(1, &mScissorRect);

    // Indicate a state transition on the resource usage.
    mCommandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(CurrentBackBuffer(),
        D3D12_RESOURCE_STATE_PRESENT, D3D12_RESOURCE_STATE_RENDER_TARGET));

    // Clear the back buffer and depth buffer.
    mCommandList->ClearRenderTargetView(CurrentBackBufferView(), Colors::LightSteelBlue, 0, nullptr);
    mCommandList->ClearDepthStencilView(DepthStencilView(), D3D12_CLEAR_FLAG_DEPTH | D3D12_CLEAR_FLAG_STENCIL, 1.0f, 0, 0, nullptr);

    // Specify the buffers we are going to render to.
    mCommandList->OMSetRenderTargets(1, &CurrentBackBufferView(), true, &DepthStencilView());

    ID3D12DescriptorHeap* descriptorHeaps[] = { mSrvDescriptorHeap.Get() };
    mCommandList->SetDescriptorHeaps(_countof(descriptorHeaps), descriptorHeaps);

    mCommandList->SetGraphicsRootSignature(mRootSignature.Get());

    // Bind all the materials used in this scene.  For structured buffers, we can bypass the heap and
    // set as a root descriptor.
    auto matBuffer = mCurrFrameResource->MaterialBuffer->Resource();
    mCommandList->SetGraphicsRootShaderResourceView(1, matBuffer->GetGPUVirtualAddress());

    auto passCB = mCurrFrameResource->PassCB->Resource();
    mCommandList->SetGraphicsRootConstantBufferView(2, passCB->GetGPUVirtualAddress());

    // Bind all the textures used in this scene.
    mCommandList->SetGraphicsRootDescriptorTable(3, mSrvDescriptorHeap->GetGPUDescriptorHandleForHeapStart());

    DrawRenderItems(mCommandList.Get(), mOpaqueRitems);

    // Indicate a state transition on the resource usage.
    mCommandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(CurrentBackBuffer(),
        D3D12_RESOURCE_STATE_RENDER_TARGET, D3D12_RESOURCE_STATE_PRESENT));

    // Done recording commands.
    ThrowIfFailed(mCommandList->Close());

    // Add the command list to the queue for execution.
    ID3D12CommandList* cmdsLists[] = { mCommandList.Get() };
    mCommandQueue->ExecuteCommandLists(_countof(cmdsLists), cmdsLists);

    // Swap the back and front buffers
    ThrowIfFailed(mSwapChain->Present(0, 0));
    mCurrBackBuffer = (mCurrBackBuffer + 1) % SwapChainBufferCount;

    // Advance the fence value to mark commands up to this fence point.
    mCurrFrameResource->Fence = ++mCurrentFence;

    // Add an instruction to the command queue to set a new fence point.
    // Because we are on the GPU timeline, the new fence point won't be
    // set until the GPU finishes processing all the commands prior to this Signal().
    mCommandQueue->Signal(mFence.Get(), mCurrentFence);
}

void InstancingAndCullingApp::OnMouseDown(WPARAM btnState, int x, int y)
{
    mLastMousePos.x = x;
    mLastMousePos.y = y;

    SetCapture(mhMainWnd);
}

void InstancingAndCullingApp::OnMouseUp(WPARAM btnState, int x, int y)
{
    ReleaseCapture();
}

void InstancingAndCullingApp::OnMouseMove(WPARAM btnState, int x, int y)
{
    if((btnState & MK_LBUTTON) != 0)
    {
        // Make each pixel correspond to a quarter of a degree.
        float dx = XMConvertToRadians(0.25f*static_cast<float>(x - mLastMousePos.x));
        float dy = XMConvertToRadians(0.25f*static_cast<float>(y - mLastMousePos.y));

        mCamera.Pitch(dy);
        mCamera.RotateY(dx);
    }

    mLastMousePos.x = x;
    mLastMousePos.y = y;
}

void InstancingAndCullingApp::OnKeyboardInput(const GameTimer& gt)
{
    const float dt = gt.DeltaTime();

    if(GetAsyncKeyState('W') & 0x8000)
        mCamera.Walk(20.0f*dt);

    if(GetAsyncKeyState('S') & 0x8000)
        mCamera.Walk(-20.0f*dt);

    if(GetAsyncKeyState('A') & 0x8000)
        mCamera.Strafe(-20.0f*dt);

    if(GetAsyncKeyState('D') & 0x8000)
        mCamera.Strafe(20.0f*dt);

    if(GetAsyncKeyState('1') & 0x8000)
        mFrustumCullingEnabled = true;

    if(GetAsyncKeyState('2') & 0x8000)
        mFrustumCullingEnabled = false;

    mCamera.UpdateViewMatrix();
}

void InstancingAndCullingApp::AnimateMaterials(const GameTimer& gt)
{

}

void InstancingAndCullingApp::UpdateInstanceData(const GameTimer& gt)
{
    XMMATRIX view = mCamera.GetView();
    XMMATRIX invView = XMMatrixInverse(&XMMatrixDeterminant(view), view);

    auto currInstanceBuffer = mCurrFrameResource->InstanceBuffer.get();
    for(auto& e : mAllRitems)
    {
        const auto& instanceData = e->Instances;

        int visibleInstanceCount = 0;

        for(UINT i = 0; i < (UINT)instanceData.size(); ++i)
        {
            XMMATRIX world = XMLoadFloat4x4(&instanceData[i].World);
            XMMATRIX texTransform = XMLoadFloat4x4(&instanceData[i].TexTransform);

            XMMATRIX invWorld = XMMatrixInverse(&XMMatrixDeterminant(world), world);

            // View space to the object's local space.
            XMMATRIX viewToLocal = XMMatrixMultiply(invView, invWorld);

            // Transform the camera frustum from view space to the object's local space.
            BoundingFrustum localSpaceFrustum;
            mCamFrustum.Transform(localSpaceFrustum, viewToLocal);

            // Perform the box/frustum intersection test in local space.
            if((localSpaceFrustum.Contains(e->Bounds) != DirectX::DISJOINT) || (mFrustumCullingEnabled==false))
            {
                InstanceData data;
                XMStoreFloat4x4(&data.World, XMMatrixTranspose(world));
                XMStoreFloat4x4(&data.TexTransform, XMMatrixTranspose(texTransform));
                data.MaterialIndex = instanceData[i].MaterialIndex;

                // Write the instance data to structured buffer for the visible objects.
                currInstanceBuffer->CopyData(visibleInstanceCount++, data);
            }
        }

        e->InstanceCount = visibleInstanceCount;

        std::wostringstream outs;
        outs.precision(6);
        outs << L"Instancing and Culling Demo" <<
            L"    " << e->InstanceCount <<
            L" objects visible out of " << e->Instances.size();
        mMainWndCaption = outs.str();
    }
}

void InstancingAndCullingApp::UpdateMaterialBuffer(const GameTimer& gt)
{
    auto currMaterialBuffer = mCurrFrameResource->MaterialBuffer.get();
    for(auto& e : mMaterials)
    {
        // Only update the cbuffer data if the constants have changed.  If the cbuffer
        // data changes, it needs to be updated for each FrameResource.
        Material* mat = e.second.get();
        if(mat->NumFramesDirty > 0)
        {
            XMMATRIX matTransform = XMLoadFloat4x4(&mat->MatTransform);

            MaterialData matData;
            matData.DiffuseAlbedo = mat->DiffuseAlbedo;
            matData.FresnelR0 = mat->FresnelR0;
            matData.Roughness = mat->Roughness;
            XMStoreFloat4x4(&matData.MatTransform, XMMatrixTranspose(matTransform));
            matData.DiffuseMapIndex = mat->DiffuseSrvHeapIndex;

            currMaterialBuffer->CopyData(mat->MatCBIndex, matData);

            // Next FrameResource need to be updated too.
            mat->NumFramesDirty--;
        }
    }
}

void InstancingAndCullingApp::UpdateMainPassCB(const GameTimer& gt)
{
    XMMATRIX view = mCamera.GetView();
    XMMATRIX proj = mCamera.GetProj();

    XMMATRIX viewProj = XMMatrixMultiply(view, proj);
    XMMATRIX invView = XMMatrixInverse(&XMMatrixDeterminant(view), view);
    XMMATRIX invProj = XMMatrixInverse(&XMMatrixDeterminant(proj), proj);
    XMMATRIX invViewProj = XMMatrixInverse(&XMMatrixDeterminant(viewProj), viewProj);

    XMStoreFloat4x4(&mMainPassCB.View, XMMatrixTranspose(view));
    XMStoreFloat4x4(&mMainPassCB.InvView, XMMatrixTranspose(invView));
    XMStoreFloat4x4(&mMainPassCB.Proj, XMMatrixTranspose(proj));
    XMStoreFloat4x4(&mMainPassCB.InvProj, XMMatrixTranspose(invProj));
    XMStoreFloat4x4(&mMainPassCB.ViewProj, XMMatrixTranspose(viewProj));
    XMStoreFloat4x4(&mMainPassCB.InvViewProj, XMMatrixTranspose(invViewProj));
    mMainPassCB.EyePosW = mCamera.GetPosition3f();
    mMainPassCB.RenderTargetSize = XMFLOAT2((float)mClientWidth, (float)mClientHeight);
    mMainPassCB.InvRenderTargetSize = XMFLOAT2(1.0f / mClientWidth, 1.0f / mClientHeight);
    mMainPassCB.NearZ = 1.0f;
    mMainPassCB.FarZ = 1000.0f;
    mMainPassCB.TotalTime = gt.TotalTime();
    mMainPassCB.DeltaTime = gt.DeltaTime();
    mMainPassCB.AmbientLight = { 0.25f, 0.25f, 0.35f, 1.0f };
    mMainPassCB.Lights[0].Direction = { 0.57735f, -0.57735f, 0.57735f };
    mMainPassCB.Lights[0].Strength = { 0.8f, 0.8f, 0.8f };
    mMainPassCB.Lights[1].Direction = { -0.57735f, -0.57735f, 0.57735f };
    mMainPassCB.Lights[1].Strength = { 0.4f, 0.4f, 0.4f };
    mMainPassCB.Lights[2].Direction = { 0.0f, -0.707f, -0.707f };
    mMainPassCB.Lights[2].Strength = { 0.2f, 0.2f, 0.2f };

    auto currPassCB = mCurrFrameResource->PassCB.get();
    currPassCB->CopyData(0, mMainPassCB);
}

void InstancingAndCullingApp::LoadTextures()
{
    auto bricksTex = std::make_unique<Texture>();
    bricksTex->Name = "bricksTex";
    bricksTex->Filename = L"../../Textures/bricks.dds";
    ThrowIfFailed(DirectX::CreateDDSTextureFromFile12(md3dDevice.Get(),
        mCommandList.Get(), bricksTex->Filename.c_str(),
        bricksTex->Resource, bricksTex->UploadHeap));

    auto stoneTex = std::make_unique<Texture>();
    stoneTex->Name = "stoneTex";
    stoneTex->Filename = L"../../Textures/stone.dds";
    ThrowIfFailed(DirectX::CreateDDSTextureFromFile12(md3dDevice.Get(),
        mCommandList.Get(), stoneTex->Filename.c_str(),
        stoneTex->Resource, stoneTex->UploadHeap));

    auto tileTex = std::make_unique<Texture>();
    tileTex->Name = "tileTex";
    tileTex->Filename = L"../../Textures/tile.dds";
    ThrowIfFailed(DirectX::CreateDDSTextureFromFile12(md3dDevice.Get(),
        mCommandList.Get(), tileTex->Filename.c_str(),
        tileTex->Resource, tileTex->UploadHeap));

    auto crateTex = std::make_unique<Texture>();
    crateTex->Name = "crateTex";
    crateTex->Filename = L"../../Textures/WoodCrate01.dds";
    ThrowIfFailed(DirectX::CreateDDSTextureFromFile12(md3dDevice.Get(),
        mCommandList.Get(), crateTex->Filename.c_str(),
        crateTex->Resource, crateTex->UploadHeap));

    auto iceTex = std::make_unique<Texture>();
    iceTex->Name = "iceTex";
    iceTex->Filename = L"../../Textures/ice.dds";
    ThrowIfFailed(DirectX::CreateDDSTextureFromFile12(md3dDevice.Get(),
        mCommandList.Get(), iceTex->Filename.c_str(),
        iceTex->Resource, iceTex->UploadHeap));

    auto grassTex = std::make_unique<Texture>();
    grassTex->Name = "grassTex";
    grassTex->Filename = L"../../Textures/grass.dds";
    ThrowIfFailed(DirectX::CreateDDSTextureFromFile12(md3dDevice.Get(),
        mCommandList.Get(), grassTex->Filename.c_str(),
        grassTex->Resource, grassTex->UploadHeap));

    auto defaultTex = std::make_unique<Texture>();
    defaultTex->Name = "defaultTex";
    defaultTex->Filename = L"../../Textures/white1x1.dds";
    ThrowIfFailed(DirectX::CreateDDSTextureFromFile12(md3dDevice.Get(),
        mCommandList.Get(), defaultTex->Filename.c_str(),
        defaultTex->Resource, defaultTex->UploadHeap));

    mTextures[bricksTex->Name] = std::move(bricksTex);
    mTextures[stoneTex->Name] = std::move(stoneTex);
    mTextures[tileTex->Name] = std::move(tileTex);
    mTextures[crateTex->Name] = std::move(crateTex);
    mTextures[iceTex->Name] = std::move(iceTex);
    mTextures[grassTex->Name] = std::move(grassTex);
    mTextures[defaultTex->Name] = std::move(defaultTex);
}

void InstancingAndCullingApp::BuildRootSignature()
{
    CD3DX12_DESCRIPTOR_RANGE texTable;
    texTable.Init(D3D12_DESCRIPTOR_RANGE_TYPE_SRV, 7, 0, 0);

    // Root parameter can be a table, root descriptor or root constants.
    CD3DX12_ROOT_PARAMETER slotRootParameter[4];

    // Perfomance TIP: Order from most frequent to least frequent.
    slotRootParameter[0].InitAsShaderResourceView(0, 1);
    slotRootParameter[1].InitAsShaderResourceView(1, 1);
    slotRootParameter[2].InitAsConstantBufferView(0);
    slotRootParameter[3].InitAsDescriptorTable(1, &texTable, D3D12_SHADER_VISIBILITY_PIXEL);

    auto staticSamplers = GetStaticSamplers();

    // A root signature is an array of root parameters.
    CD3DX12_ROOT_SIGNATURE_DESC rootSigDesc(4, slotRootParameter,
        (UINT)staticSamplers.size(), staticSamplers.data(),
        D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT);

    // create a root signature with a single slot which points to a descriptor range consisting of a single constant buffer
    ComPtr<ID3DBlob> serializedRootSig = nullptr;
    ComPtr<ID3DBlob> errorBlob = nullptr;
    HRESULT hr = D3D12SerializeRootSignature(&rootSigDesc, D3D_ROOT_SIGNATURE_VERSION_1,
        serializedRootSig.GetAddressOf(), errorBlob.GetAddressOf());

    if(errorBlob != nullptr)
    {
        ::OutputDebugStringA((char*)errorBlob->GetBufferPointer());
    }
    ThrowIfFailed(hr);

    ThrowIfFailed(md3dDevice->CreateRootSignature(
        0,
        serializedRootSig->GetBufferPointer(),
        serializedRootSig->GetBufferSize(),
        IID_PPV_ARGS(mRootSignature.GetAddressOf())));
}

void InstancingAndCullingApp::BuildDescriptorHeaps()
{
    //
    // Create the SRV heap.
    //
    D3D12_DESCRIPTOR_HEAP_DESC srvHeapDesc = {};
    srvHeapDesc.NumDescriptors = 7;
    srvHeapDesc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
    srvHeapDesc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;
    ThrowIfFailed(md3dDevice->CreateDescriptorHeap(&srvHeapDesc, IID_PPV_ARGS(&mSrvDescriptorHeap)));

    //
    // Fill out the heap with actual descriptors.
    //
    CD3DX12_CPU_DESCRIPTOR_HANDLE hDescriptor(mSrvDescriptorHeap->GetCPUDescriptorHandleForHeapStart());

    auto bricksTex = mTextures["bricksTex"]->Resource;
    auto stoneTex = mTextures["stoneTex"]->Resource;
    auto tileTex = mTextures["tileTex"]->Resource;
    auto crateTex = mTextures["crateTex"]->Resource;
    auto iceTex = mTextures["iceTex"]->Resource;
    auto grassTex = mTextures["grassTex"]->Resource;
    auto defaultTex = mTextures["defaultTex"]->Resource;

    D3D12_SHADER_RESOURCE_VIEW_DESC srvDesc = {};
    srvDesc.Shader4ComponentMapping = D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING;
    srvDesc.Format = bricksTex->GetDesc().Format;
    srvDesc.ViewDimension = D3D12_SRV_DIMENSION_TEXTURE2D;
    srvDesc.Texture2D.MostDetailedMip = 0;
    srvDesc.Texture2D.MipLevels = bricksTex->GetDesc().MipLevels;
    srvDesc.Texture2D.ResourceMinLODClamp = 0.0f;
    md3dDevice->CreateShaderResourceView(bricksTex.Get(), &srvDesc, hDescriptor);

    // next descriptor
    hDescriptor.Offset(1, mCbvSrvDescriptorSize);

    srvDesc.Format = stoneTex->GetDesc().Format;
    srvDesc.Texture2D.MipLevels = stoneTex->GetDesc().MipLevels;
    md3dDevice->CreateShaderResourceView(stoneTex.Get(), &srvDesc, hDescriptor);

    // next descriptor
    hDescriptor.Offset(1, mCbvSrvDescriptorSize);

    srvDesc.Format = tileTex->GetDesc().Format;
    srvDesc.Texture2D.MipLevels = tileTex->GetDesc().MipLevels;
    md3dDevice->CreateShaderResourceView(tileTex.Get(), &srvDesc, hDescriptor);

    // next descriptor
    hDescriptor.Offset(1, mCbvSrvDescriptorSize);

    srvDesc.Format = crateTex->GetDesc().Format;
    srvDesc.Texture2D.MipLevels = crateTex->GetDesc().MipLevels;
    md3dDevice->CreateShaderResourceView(crateTex.Get(), &srvDesc, hDescriptor);

    // next descriptor
    hDescriptor.Offset(1, mCbvSrvDescriptorSize);

    srvDesc.Format = iceTex->GetDesc().Format;
    srvDesc.Texture2D.MipLevels = iceTex->GetDesc().MipLevels;
    md3dDevice->CreateShaderResourceView(iceTex.Get(), &srvDesc, hDescriptor);

    // next descriptor
    hDescriptor.Offset(1, mCbvSrvDescriptorSize);

    srvDesc.Format = grassTex->GetDesc().Format;
    srvDesc.Texture2D.MipLevels = grassTex->GetDesc().MipLevels;
    md3dDevice->CreateShaderResourceView(grassTex.Get(), &srvDesc, hDescriptor);

    // next descriptor
    hDescriptor.Offset(1, mCbvSrvDescriptorSize);

    srvDesc.Format = defaultTex->GetDesc().Format;
    srvDesc.Texture2D.MipLevels = defaultTex->GetDesc().MipLevels;
    md3dDevice->CreateShaderResourceView(defaultTex.Get(), &srvDesc, hDescriptor);
}

void InstancingAndCullingApp::BuildShadersAndInputLayout()
{
    const D3D_SHADER_MACRO alphaTestDefines[] =
    {
        "ALPHA_TEST", "1",
        NULL, NULL
    };

    mShaders["standardVS"] = d3dUtil::CompileShader(L"Shaders\\Default.hlsl", nullptr, "VS", "vs_5_1");
    mShaders["opaquePS"] = d3dUtil::CompileShader(L"Shaders\\Default.hlsl", nullptr, "PS", "ps_5_1");

    mInputLayout =
    {
        { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
        { "NORMAL", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 12, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
        { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT, 0, 24, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
    };
}

void InstancingAndCullingApp::BuildSkullGeometry()
{
    std::ifstream fin("Models/skull.txt");

    if(!fin)
    {
        MessageBox(0, L"Models/skull.txt not found.", 0, 0);
        return;
    }

    UINT vcount = 0;
    UINT tcount = 0;
    std::string ignore;

    fin >> ignore >> vcount;
    fin >> ignore >> tcount;
    fin >> ignore >> ignore >> ignore >> ignore;

    XMFLOAT3 vMinf3(+MathHelper::Infinity, +MathHelper::Infinity, +MathHelper::Infinity);
    XMFLOAT3 vMaxf3(-MathHelper::Infinity, -MathHelper::Infinity, -MathHelper::Infinity);

    XMVECTOR vMin = XMLoadFloat3(&vMinf3);
    XMVECTOR vMax = XMLoadFloat3(&vMaxf3);

    std::vector<Vertex> vertices(vcount);
    for(UINT i = 0; i < vcount; ++i)
    {
        fin >> vertices[i].Pos.x >> vertices[i].Pos.y >> vertices[i].Pos.z;
        fin >> vertices[i].Normal.x >> vertices[i].Normal.y >> vertices[i].Normal.z;

        XMVECTOR P = XMLoadFloat3(&vertices[i].Pos);

        // Project point onto unit sphere and generate spherical texture coordinates.
        XMFLOAT3 spherePos;
        XMStoreFloat3(&spherePos, XMVector3Normalize(P));

        float theta = atan2f(spherePos.z, spherePos.x);

        // Put in [0, 2pi].
        if(theta < 0.0f)
            theta += XM_2PI;

        float phi = acosf(spherePos.y);

        float u = theta / (2.0f*XM_PI);
        float v = phi / XM_PI;

        vertices[i].TexC = { u, v };

        vMin = XMVectorMin(vMin, P);
        vMax = XMVectorMax(vMax, P);
    }

    BoundingBox bounds;
    XMStoreFloat3(&bounds.Center, 0.5f*(vMin + vMax));
    XMStoreFloat3(&bounds.Extents, 0.5f*(vMax - vMin));

    fin >> ignore;
    fin >> ignore;
    fin >> ignore;

    std::vector<std::int32_t> indices(3 * tcount);
    for(UINT i = 0; i < tcount; ++i)
    {
        fin >> indices[i * 3 + 0] >> indices[i * 3 + 1] >> indices[i * 3 + 2];
    }

    fin.close();

    //
    // Pack the indices of all the meshes into one index buffer.
    //

    const UINT vbByteSize = (UINT)vertices.size() * sizeof(Vertex);

    const UINT ibByteSize = (UINT)indices.size() * sizeof(std::int32_t);

    auto geo = std::make_unique<MeshGeometry>();
    geo->Name = "skullGeo";

    ThrowIfFailed(D3DCreateBlob(vbByteSize, &geo->VertexBufferCPU));
    CopyMemory(geo->VertexBufferCPU->GetBufferPointer(), vertices.data(), vbByteSize);

    ThrowIfFailed(D3DCreateBlob(ibByteSize, &geo->IndexBufferCPU));
    CopyMemory(geo->IndexBufferCPU->GetBufferPointer(), indices.data(), ibByteSize);

    geo->VertexBufferGPU = d3dUtil::CreateDefaultBuffer(md3dDevice.Get(),
        mCommandList.Get(), vertices.data(), vbByteSize, geo->VertexBufferUploader);

    geo->IndexBufferGPU = d3dUtil::CreateDefaultBuffer(md3dDevice.Get(),
        mCommandList.Get(), indices.data(), ibByteSize, geo->IndexBufferUploader);

    geo->VertexByteStride = sizeof(Vertex);
    geo->VertexBufferByteSize = vbByteSize;
    geo->IndexFormat = DXGI_FORMAT_R32_UINT;
    geo->IndexBufferByteSize = ibByteSize;

    SubmeshGeometry submesh;
    submesh.IndexCount = (UINT)indices.size();
    submesh.StartIndexLocation = 0;
    submesh.BaseVertexLocation = 0;
    submesh.Bounds = bounds;

    geo->DrawArgs["skull"] = submesh;

    mGeometries[geo->Name] = std::move(geo);
}

void InstancingAndCullingApp::BuildPSOs()
{
    D3D12_GRAPHICS_PIPELINE_STATE_DESC opaquePsoDesc;

    //
    // PSO for opaque objects.
    //
    ZeroMemory(&opaquePsoDesc, sizeof(D3D12_GRAPHICS_PIPELINE_STATE_DESC));
    opaquePsoDesc.InputLayout = { mInputLayout.data(), (UINT)mInputLayout.size() };
    opaquePsoDesc.pRootSignature = mRootSignature.Get();
    opaquePsoDesc.VS =
    {
        reinterpret_cast<BYTE*>(mShaders["standardVS"]->GetBufferPointer()),
        mShaders["standardVS"]->GetBufferSize()
    };
    opaquePsoDesc.PS =
    {
        reinterpret_cast<BYTE*>(mShaders["opaquePS"]->GetBufferPointer()),
        mShaders["opaquePS"]->GetBufferSize()
    };
    opaquePsoDesc.RasterizerState = CD3DX12_RASTERIZER_DESC(D3D12_DEFAULT);
    opaquePsoDesc.BlendState = CD3DX12_BLEND_DESC(D3D12_DEFAULT);
    opaquePsoDesc.DepthStencilState = CD3DX12_DEPTH_STENCIL_DESC(D3D12_DEFAULT);
    opaquePsoDesc.SampleMask = UINT_MAX;
    opaquePsoDesc.PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE;
    opaquePsoDesc.NumRenderTargets = 1;
    opaquePsoDesc.RTVFormats[0] = mBackBufferFormat;
    opaquePsoDesc.SampleDesc.Count = m4xMsaaState ? 4 : 1;
    opaquePsoDesc.SampleDesc.Quality = m4xMsaaState ? (m4xMsaaQuality - 1) : 0;
    opaquePsoDesc.DSVFormat = mDepthStencilFormat;
    ThrowIfFailed(md3dDevice->CreateGraphicsPipelineState(&opaquePsoDesc, IID_PPV_ARGS(&mPSOs["opaque"])));
}

void InstancingAndCullingApp::BuildFrameResources()
{
    for(int i = 0; i < gNumFrameResources; ++i)
    {
        mFrameResources.push_back(std::make_unique<FrameResource>(md3dDevice.Get(),
            1, (UINT)mAllRitems.size(), (UINT)mMaterials.size()));
    }
}

void InstancingAndCullingApp::BuildMaterials()
{
    auto bricks0 = std::make_unique<Material>();
    bricks0->Name = "bricks0";
    bricks0->MatCBIndex = 0;
    bricks0->DiffuseSrvHeapIndex = 0;
    bricks0->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
    bricks0->FresnelR0 = XMFLOAT3(0.02f, 0.02f, 0.02f);
    bricks0->Roughness = 0.1f;

    auto stone0 = std::make_unique<Material>();
    stone0->Name = "stone0";
    stone0->MatCBIndex = 1;
    stone0->DiffuseSrvHeapIndex = 1;
    stone0->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
    stone0->FresnelR0 = XMFLOAT3(0.05f, 0.05f, 0.05f);
    stone0->Roughness = 0.3f;

    auto tile0 = std::make_unique<Material>();
    tile0->Name = "tile0";
    tile0->MatCBIndex = 2;
    tile0->DiffuseSrvHeapIndex = 2;
    tile0->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
    tile0->FresnelR0 = XMFLOAT3(0.02f, 0.02f, 0.02f);
    tile0->Roughness = 0.3f;

    auto crate0 = std::make_unique<Material>();
    crate0->Name = "checkboard0";
    crate0->MatCBIndex = 3;
    crate0->DiffuseSrvHeapIndex = 3;
    crate0->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
    crate0->FresnelR0 = XMFLOAT3(0.05f, 0.05f, 0.05f);
    crate0->Roughness = 0.2f;

    auto ice0 = std::make_unique<Material>();
    ice0->Name = "ice0";
    ice0->MatCBIndex = 4;
    ice0->DiffuseSrvHeapIndex = 4;
    ice0->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
    ice0->FresnelR0 = XMFLOAT3(0.1f, 0.1f, 0.1f);
    ice0->Roughness = 0.0f;

    auto grass0 = std::make_unique<Material>();
    grass0->Name = "grass0";
    grass0->MatCBIndex = 5;
    grass0->DiffuseSrvHeapIndex = 5;
    grass0->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
    grass0->FresnelR0 = XMFLOAT3(0.05f, 0.05f, 0.05f);
    grass0->Roughness = 0.2f;

    auto skullMat = std::make_unique<Material>();
    skullMat->Name = "skullMat";
    skullMat->MatCBIndex = 6;
    skullMat->DiffuseSrvHeapIndex = 6;
    skullMat->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f);
    skullMat->FresnelR0 = XMFLOAT3(0.05f, 0.05f, 0.05f);
    skullMat->Roughness = 0.5f;

    mMaterials["bricks0"] = std::move(bricks0);
    mMaterials["stone0"] = std::move(stone0);
    mMaterials["tile0"] = std::move(tile0);
    mMaterials["crate0"] = std::move(crate0);
    mMaterials["ice0"] = std::move(ice0);
    mMaterials["grass0"] = std::move(grass0);
    mMaterials["skullMat"] = std::move(skullMat);
}

void InstancingAndCullingApp::BuildRenderItems()
{
    auto skullRitem = std::make_unique<RenderItem>();
    skullRitem->World = MathHelper::Identity4x4();
    skullRitem->TexTransform = MathHelper::Identity4x4();
    skullRitem->ObjCBIndex = 0;
    skullRitem->Mat = mMaterials["tile0"].get();
    skullRitem->Geo = mGeometries["skullGeo"].get();
    skullRitem->PrimitiveType = D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST;
    skullRitem->InstanceCount = 0;
    skullRitem->IndexCount = skullRitem->Geo->DrawArgs["skull"].IndexCount;
    skullRitem->StartIndexLocation = skullRitem->Geo->DrawArgs["skull"].StartIndexLocation;
    skullRitem->BaseVertexLocation = skullRitem->Geo->DrawArgs["skull"].BaseVertexLocation;
    skullRitem->Bounds = skullRitem->Geo->DrawArgs["skull"].Bounds;

    // Generate instance data.
    const int n = 5;
    skullRitem->Instances.resize(n*n*n);

    float width = 200.0f;
    float height = 200.0f;
    float depth = 200.0f;

    float x = -0.5f*width;
    float y = -0.5f*height;
    float z = -0.5f*depth;
    float dx = width / (n - 1);
    float dy = height / (n - 1);
    float dz = depth / (n - 1);
    for(int k = 0; k < n; ++k)
    {
        for(int i = 0; i < n; ++i)
        {
            for(int j = 0; j < n; ++j)
            {
                int index = k*n*n + i*n + j;
                // Position instanced along a 3D grid.
                skullRitem->Instances[index].World = XMFLOAT4X4(
                    1.0f, 0.0f, 0.0f, 0.0f,
                    0.0f, 1.0f, 0.0f, 0.0f,
                    0.0f, 0.0f, 1.0f, 0.0f,
                    x + j*dx, y + i*dy, z + k*dz, 1.0f);

                XMStoreFloat4x4(&skullRitem->Instances[index].TexTransform, XMMatrixScaling(2.0f, 2.0f, 1.0f));
                skullRitem->Instances[index].MaterialIndex = index % mMaterials.size();
            }
        }
    }


    mAllRitems.push_back(std::move(skullRitem));

    // All the render items are opaque.
    for(auto& e : mAllRitems)
        mOpaqueRitems.push_back(e.get());
}

void InstancingAndCullingApp::DrawRenderItems(ID3D12GraphicsCommandList* cmdList, const std::vector<RenderItem*>& ritems)
{
    // For each render item...
    for(size_t i = 0; i < ritems.size(); ++i)
    {
        auto ri = ritems[i];

        cmdList->IASetVertexBuffers(0, 1, &ri->Geo->VertexBufferView());
        cmdList->IASetIndexBuffer(&ri->Geo->IndexBufferView());
        cmdList->IASetPrimitiveTopology(ri->PrimitiveType);

        // Set the instance buffer to use for this render-item.  For structured buffers, we can bypass
        // the heap and set as a root descriptor.
        auto instanceBuffer = mCurrFrameResource->InstanceBuffer->Resource();
        mCommandList->SetGraphicsRootShaderResourceView(0, instanceBuffer->GetGPUVirtualAddress());

        cmdList->DrawIndexedInstanced(ri->IndexCount, ri->InstanceCount, ri->StartIndexLocation, ri->BaseVertexLocation, 0);
    }
}

std::array<const CD3DX12_STATIC_SAMPLER_DESC, 6> InstancingAndCullingApp::GetStaticSamplers()
{
    // Applications usually only need a handful of samplers.  So just define them all up front
    // and keep them available as part of the root signature.

    const CD3DX12_STATIC_SAMPLER_DESC pointWrap(
        0, // shaderRegister
        D3D12_FILTER_MIN_MAG_MIP_POINT, // filter
        D3D12_TEXTURE_ADDRESS_MODE_WRAP,  // addressU
        D3D12_TEXTURE_ADDRESS_MODE_WRAP,  // addressV
        D3D12_TEXTURE_ADDRESS_MODE_WRAP); // addressW

    const CD3DX12_STATIC_SAMPLER_DESC pointClamp(
        1, // shaderRegister
        D3D12_FILTER_MIN_MAG_MIP_POINT, // filter
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP,  // addressU
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP,  // addressV
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP); // addressW

    const CD3DX12_STATIC_SAMPLER_DESC linearWrap(
        2, // shaderRegister
        D3D12_FILTER_MIN_MAG_MIP_LINEAR, // filter
        D3D12_TEXTURE_ADDRESS_MODE_WRAP,  // addressU
        D3D12_TEXTURE_ADDRESS_MODE_WRAP,  // addressV
        D3D12_TEXTURE_ADDRESS_MODE_WRAP); // addressW

    const CD3DX12_STATIC_SAMPLER_DESC linearClamp(
        3, // shaderRegister
        D3D12_FILTER_MIN_MAG_MIP_LINEAR, // filter
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP,  // addressU
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP,  // addressV
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP); // addressW

    const CD3DX12_STATIC_SAMPLER_DESC anisotropicWrap(
        4, // shaderRegister
        D3D12_FILTER_ANISOTROPIC, // filter
        D3D12_TEXTURE_ADDRESS_MODE_WRAP,  // addressU
        D3D12_TEXTURE_ADDRESS_MODE_WRAP,  // addressV
        D3D12_TEXTURE_ADDRESS_MODE_WRAP,  // addressW
        0.0f,                             // mipLODBias
        8);                               // maxAnisotropy

    const CD3DX12_STATIC_SAMPLER_DESC anisotropicClamp(
        5, // shaderRegister
        D3D12_FILTER_ANISOTROPIC, // filter
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP,  // addressU
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP,  // addressV
        D3D12_TEXTURE_ADDRESS_MODE_CLAMP,  // addressW
        0.0f,                              // mipLODBias
        8);                                // maxAnisotropy

    return {
        pointWrap, pointClamp,
        linearWrap, linearClamp,
        anisotropicWrap, anisotropicClamp };
}