Introduction to 3D Game …ogramming with DirectX 12/Introduction-to-3D-Game-Programming-with-DirectX-12.ISO/Code.Textures/Chapter 17 Picking/Picking/PickingApp.cpp

C/C++ Source or Header | 2016-03-02 | 33.4 KB | 964 lines

//***************************************************************************************
// PickingApp.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;

    bool Visible = true;

    BoundingBox Bounds;

    // 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;

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

enum class RenderLayer : int
{
    Opaque = 0,
    Highlight,
    Count
};

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

    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 UpdateObjectCBs(const GameTimer& gt);
    void UpdateMaterialBuffer(const GameTimer& gt);
    void UpdateMainPassCB(const GameTimer& gt);

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

    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*> mRitemLayer[(int)RenderLayer::Count];

    RenderItem* mPickedRitem = nullptr;

    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
    {
        PickingApp 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;
    }
}

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

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

bool PickingApp::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.LookAt(
        XMFLOAT3(5.0f, 4.0f, -15.0f),
        XMFLOAT3(0.0f, 1.0f, 0.0f),
        XMFLOAT3(0.0f, 1.0f, 0.0f));

    LoadTextures();
    BuildRootSignature();
    BuildDescriptorHeaps();
    BuildShadersAndInputLayout();
    BuildCarGeometry();
    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 PickingApp::OnResize()
{
    D3DApp::OnResize();

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

void PickingApp::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);
    UpdateObjectCBs(gt);
    UpdateMaterialBuffer(gt);
    UpdateMainPassCB(gt);
}

void PickingApp::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());

    auto passCB = mCurrFrameResource->PassCB->Resource();
    mCommandList->SetGraphicsRootConstantBufferView(1, passCB->GetGPUVirtualAddress());

    // 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(2, matBuffer->GetGPUVirtualAddress());

    // Bind all the textures used in this scene.  Observe
    // that we only have to specify the first descriptor in the table.
    // The root signature knows how many descriptors are expected in the table.
    mCommandList->SetGraphicsRootDescriptorTable(3, mSrvDescriptorHeap->GetGPUDescriptorHandleForHeapStart());

    DrawRenderItems(mCommandList.Get(), mRitemLayer[(int)RenderLayer::Opaque]);

    mCommandList->SetPipelineState(mPSOs["highlight"].Get());
    DrawRenderItems(mCommandList.Get(), mRitemLayer[(int)RenderLayer::Highlight]);

    // 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 PickingApp::OnMouseDown(WPARAM btnState, int x, int y)
{
    if((btnState & MK_LBUTTON) != 0)
    {
        mLastMousePos.x = x;
        mLastMousePos.y = y;

        SetCapture(mhMainWnd);
    }
    else if((btnState & MK_RBUTTON) != 0)
    {
        Pick(x, y);
    }
}

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

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

    if(GetAsyncKeyState('W') & 0x8000)
        mCamera.Walk(10.0f*dt);

    if(GetAsyncKeyState('S') & 0x8000)
        mCamera.Walk(-10.0f*dt);

    if(GetAsyncKeyState('A') & 0x8000)
        mCamera.Strafe(-10.0f*dt);

    if(GetAsyncKeyState('D') & 0x8000)
        mCamera.Strafe(10.0f*dt);

    mCamera.UpdateViewMatrix();
}

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

}

void PickingApp::UpdateObjectCBs(const GameTimer& gt)
{
    auto currObjectCB = mCurrFrameResource->ObjectCB.get();
    for(auto& e : mAllRitems)
    {
        // Only update the cbuffer data if the constants have changed.
        // This needs to be tracked per frame resource.
        if(e->NumFramesDirty > 0)
        {
            XMMATRIX world = XMLoadFloat4x4(&e->World);
            XMMATRIX texTransform = XMLoadFloat4x4(&e->TexTransform);

            ObjectConstants objConstants;
            XMStoreFloat4x4(&objConstants.World, XMMatrixTranspose(world));
            XMStoreFloat4x4(&objConstants.TexTransform, XMMatrixTranspose(texTransform));
            objConstants.MaterialIndex = e->Mat->MatCBIndex;

            currObjectCB->CopyData(e->ObjCBIndex, objConstants);

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

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

    mTextures[defaultDiffuseTex->Name] = std::move(defaultDiffuseTex);
}

void PickingApp::BuildRootSignature()
{
    CD3DX12_DESCRIPTOR_RANGE texTable;
    texTable.Init(D3D12_DESCRIPTOR_RANGE_TYPE_SRV, 4, 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].InitAsConstantBufferView(0);
    slotRootParameter[1].InitAsConstantBufferView(1);
    slotRootParameter[2].InitAsShaderResourceView(0, 1);
    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 PickingApp::BuildDescriptorHeaps()
{
    //
    // Create the SRV heap.
    //
    D3D12_DESCRIPTOR_HEAP_DESC srvHeapDesc = {};
    srvHeapDesc.NumDescriptors = 1;
    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 defaultDiffuseTex = mTextures["defaultDiffuseTex"]->Resource;

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

void PickingApp::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 PickingApp::BuildCarGeometry()
{
    std::ifstream fin("Models/car.txt");

    if(!fin)
    {
        MessageBox(0, L"Models/car.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);

        vertices[i].TexC = { 0.0f, 0.0f };

        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 = "carGeo";

    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["car"] = submesh;

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

void PickingApp::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"])));

    //
    // PSO for highlight objects
    //

    D3D12_GRAPHICS_PIPELINE_STATE_DESC highlightPsoDesc = opaquePsoDesc;

    // Change the depth test from < to <= so that if we draw the same triangle twice, it will
    // still pass the depth test.  This is needed because we redraw the picked triangle with a
    // different material to highlight it.  If we do not use <=, the triangle will fail the
    // depth test the 2nd time we try and draw it.
    highlightPsoDesc.DepthStencilState.DepthFunc = D3D12_COMPARISON_FUNC_LESS_EQUAL;

    // Standard transparency blending.
    D3D12_RENDER_TARGET_BLEND_DESC transparencyBlendDesc;
    transparencyBlendDesc.BlendEnable = true;
    transparencyBlendDesc.LogicOpEnable = false;
    transparencyBlendDesc.SrcBlend = D3D12_BLEND_SRC_ALPHA;
    transparencyBlendDesc.DestBlend = D3D12_BLEND_INV_SRC_ALPHA;
    transparencyBlendDesc.BlendOp = D3D12_BLEND_OP_ADD;
    transparencyBlendDesc.SrcBlendAlpha = D3D12_BLEND_ONE;
    transparencyBlendDesc.DestBlendAlpha = D3D12_BLEND_ZERO;
    transparencyBlendDesc.BlendOpAlpha = D3D12_BLEND_OP_ADD;
    transparencyBlendDesc.LogicOp = D3D12_LOGIC_OP_NOOP;
    transparencyBlendDesc.RenderTargetWriteMask = D3D12_COLOR_WRITE_ENABLE_ALL;

    highlightPsoDesc.BlendState.RenderTarget[0] = transparencyBlendDesc;
    ThrowIfFailed(md3dDevice->CreateGraphicsPipelineState(&highlightPsoDesc, IID_PPV_ARGS(&mPSOs["highlight"])));
}

void PickingApp::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 PickingApp::BuildMaterials()
{
    auto gray0 = std::make_unique<Material>();
    gray0->Name = "gray0";
    gray0->MatCBIndex = 0;
    gray0->DiffuseSrvHeapIndex = 0;
    gray0->DiffuseAlbedo = XMFLOAT4(0.7f, 0.7f, 0.7f, 1.0f);
    gray0->FresnelR0 = XMFLOAT3(0.04f, 0.04f, 0.04f);
    gray0->Roughness = 0.0f;

    auto highlight0 = std::make_unique<Material>();
    highlight0->Name = "highlight0";
    highlight0->MatCBIndex = 1;
    highlight0->DiffuseSrvHeapIndex = 0;
    highlight0->DiffuseAlbedo = XMFLOAT4(1.0f, 1.0f, 0.0f, 0.6f);
    highlight0->FresnelR0 = XMFLOAT3(0.06f, 0.06f, 0.06f);
    highlight0->Roughness = 0.0f;


    mMaterials["gray0"] = std::move(gray0);
    mMaterials["highlight0"] = std::move(highlight0);
}

void PickingApp::BuildRenderItems()
{
    auto carRitem = std::make_unique<RenderItem>();
    XMStoreFloat4x4(&carRitem->World, XMMatrixScaling(1.0f, 1.0f, 1.0f)*XMMatrixTranslation(0.0f, 1.0f, 0.0f));
    XMStoreFloat4x4(&carRitem->TexTransform, XMMatrixScaling(1.0f, 1.0f, 1.0f));
    carRitem->ObjCBIndex = 0;
    carRitem->Mat = mMaterials["gray0"].get();
    carRitem->Geo = mGeometries["carGeo"].get();
    carRitem->PrimitiveType = D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST;
    carRitem->Bounds = carRitem->Geo->DrawArgs["car"].Bounds;
    carRitem->IndexCount = carRitem->Geo->DrawArgs["car"].IndexCount;
    carRitem->StartIndexLocation = carRitem->Geo->DrawArgs["car"].StartIndexLocation;
    carRitem->BaseVertexLocation = carRitem->Geo->DrawArgs["car"].BaseVertexLocation;
    mRitemLayer[(int)RenderLayer::Opaque].push_back(carRitem.get());

    auto pickedRitem = std::make_unique<RenderItem>();
    pickedRitem->World = MathHelper::Identity4x4();
    pickedRitem->TexTransform = MathHelper::Identity4x4();
    pickedRitem->ObjCBIndex = 1;
    pickedRitem->Mat = mMaterials["highlight0"].get();
    pickedRitem->Geo = mGeometries["carGeo"].get();
    pickedRitem->PrimitiveType = D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST;

    // Picked triangle is not visible until one is picked.
    pickedRitem->Visible = false;

    // DrawCall parameters are filled out when a triangle is picked.
    pickedRitem->IndexCount = 0;
    pickedRitem->StartIndexLocation = 0;
    pickedRitem->BaseVertexLocation = 0;
    mPickedRitem = pickedRitem.get();
    mRitemLayer[(int)RenderLayer::Highlight].push_back(pickedRitem.get());


    mAllRitems.push_back(std::move(carRitem));
    mAllRitems.push_back(std::move(pickedRitem));
}

void PickingApp::DrawRenderItems(ID3D12GraphicsCommandList* cmdList, const std::vector<RenderItem*>& ritems)
{
    UINT objCBByteSize = d3dUtil::CalcConstantBufferByteSize(sizeof(ObjectConstants));

    auto objectCB = mCurrFrameResource->ObjectCB->Resource();

    // For each render item...
    for(size_t i = 0; i < ritems.size(); ++i)
    {
        auto ri = ritems[i];

        if(ri->Visible == false)
            continue;

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

        D3D12_GPU_VIRTUAL_ADDRESS objCBAddress = objectCB->GetGPUVirtualAddress() + ri->ObjCBIndex*objCBByteSize;

        cmdList->SetGraphicsRootConstantBufferView(0, objCBAddress);

        cmdList->DrawIndexedInstanced(ri->IndexCount, 1, ri->StartIndexLocation, ri->BaseVertexLocation, 0);
    }
}

std::array<const CD3DX12_STATIC_SAMPLER_DESC, 6> PickingApp::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 };
}

void PickingApp::Pick(int sx, int sy)
{
    XMFLOAT4X4 P = mCamera.GetProj4x4f();

    // Compute picking ray in view space.
    float vx = (+2.0f*sx / mClientWidth - 1.0f) / P(0, 0);
    float vy = (-2.0f*sy / mClientHeight + 1.0f) / P(1, 1);

    // Ray definition in view space.
    XMVECTOR rayOrigin = XMVectorSet(0.0f, 0.0f, 0.0f, 1.0f);
    XMVECTOR rayDir = XMVectorSet(vx, vy, 1.0f, 0.0f);

    XMMATRIX V = mCamera.GetView();
    XMMATRIX invView = XMMatrixInverse(&XMMatrixDeterminant(V), V);

    // Assume nothing is picked to start, so the picked render-item is invisible.
    mPickedRitem->Visible = false;

    // Check if we picked an opaque render item.  A real app might keep a separate "picking list"
    // of objects that can be selected.
    for(auto ri : mRitemLayer[(int)RenderLayer::Opaque])
    {
        auto geo = ri->Geo;

        // Skip invisible render-items.
        if(ri->Visible == false)
            continue;

        XMMATRIX W = XMLoadFloat4x4(&ri->World);
        XMMATRIX invWorld = XMMatrixInverse(&XMMatrixDeterminant(W), W);

        // Tranform ray to vi space of Mesh.
        XMMATRIX toLocal = XMMatrixMultiply(invView, invWorld);

        rayOrigin = XMVector3TransformCoord(rayOrigin, toLocal);
        rayDir = XMVector3TransformNormal(rayDir, toLocal);

        // Make the ray direction unit length for the intersection tests.
        rayDir = XMVector3Normalize(rayDir);

        // If we hit the bounding box of the Mesh, then we might have picked a Mesh triangle,
        // so do the ray/triangle tests.
        //
        // If we did not hit the bounding box, then it is impossible that we hit
        // the Mesh, so do not waste effort doing ray/triangle tests.
        float tmin = 0.0f;
        if(ri->Bounds.Intersects(rayOrigin, rayDir, tmin))
        {
            // NOTE: For the demo, we know what to cast the vertex/index data to.  If we were mixing
            // formats, some metadata would be needed to figure out what to cast it to.
            auto vertices = (Vertex*)geo->VertexBufferCPU->GetBufferPointer();
            auto indices = (std::uint32_t*)geo->IndexBufferCPU->GetBufferPointer();
            UINT triCount = ri->IndexCount / 3;

            // Find the nearest ray/triangle intersection.
            tmin = MathHelper::Infinity;
            for(UINT i = 0; i < triCount; ++i)
            {
                // Indices for this triangle.
                UINT i0 = indices[i * 3 + 0];
                UINT i1 = indices[i * 3 + 1];
                UINT i2 = indices[i * 3 + 2];

                // Vertices for this triangle.
                XMVECTOR v0 = XMLoadFloat3(&vertices[i0].Pos);
                XMVECTOR v1 = XMLoadFloat3(&vertices[i1].Pos);
                XMVECTOR v2 = XMLoadFloat3(&vertices[i2].Pos);

                // We have to iterate over all the triangles in order to find the nearest intersection.
                float t = 0.0f;
                if(TriangleTests::Intersects(rayOrigin, rayDir, v0, v1, v2, t))
                {
                    if(t < tmin)
                    {
                        // This is the new nearest picked triangle.
                        tmin = t;
                        UINT pickedTriangle = i;

                        mPickedRitem->Visible = true;
                        mPickedRitem->IndexCount = 3;
                        mPickedRitem->BaseVertexLocation = 0;

                        // Picked render item needs same world matrix as object picked.
                        mPickedRitem->World = ri->World;
                        mPickedRitem->NumFramesDirty = gNumFrameResources;

                        // Offset to the picked triangle in the mesh index buffer.
                        mPickedRitem->StartIndexLocation = 3 * pickedTriangle;
                    }
                }
            }
        }
    }
}