标签：return 渲染 hr false buffer 添加 command D3D12 三角形

让我们在场景中添加一些颜色。 在本教程中，我们将为顶点添加颜色以为三角形着色。 这涉及更新顶点着色器以将颜色传递给像素着色器，像素着色器以输出传递给它的颜色，顶点结构添加颜色属性，输入布局包含颜色输入元素。

介绍

在本教程中，我们将为三角形添加颜色。 这涉及向顶点结构添加属性，更改顶点着色器以接受颜色并将其传递，更新像素着色器以返回从光栅化器传递给它的插值像素颜色，并将输入元素添加到 输入布局
这是一个很短的教程，所以我们现在就可以开始。

新的顶点结构

我们可以定义一个具有4个浮点变量的结构，一个用于红色通道，一个用于绿色通道，一个用于蓝色通道，一个用于alpha通道。 我们可以使用DirectX数学XMFLOAT4类型来做到这一点。
除了在顶点结构中添加XMFLOAT4之外，我们还将在顶点结构中添加一个构造函数，以使创建顶点更加容易。

struct Vertex {
    Vertex(float x, float y, float z, float r, float g, float b, float a) : pos(x, y, z), color(r, g, b, z) {}
    XMFLOAT3 pos;
    XMFLOAT4 color;
};

更新了输入布局

我们将在输入布局中添加一个颜色元素。 我们的颜色是4个浮点值，因此我们将DXGI_FORMAT_R32G32B32A32_FLOAT用作元素格式。 它是在position属性之后定义的，它是12个字节，因此我们需要说color元素从顶点结构开始的12个字节，这就是第五个参数为12的原因。

D3D12_INPUT_ELEMENT_DESC inputLayout[] =
{
    { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
    { "COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 }
};

新顶点数组

我们将为三角形创建的每个顶点添加一个颜色值。 第一个顶点将为红色，第二个顶点将为绿色，第三个顶点将为蓝色。 我们可以这样定义顶点，因为我们添加了自定义顶点结构构造函数。

Vertex vList[] = {
    { 0.0f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f },
    { 0.5f, -0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f },
    { -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f },
};

顶点着色器

我们向顶点着色器文件添加了两个结构。 输入有一个结构，输出有一个结构。 顶点着色器中的输出结构需要匹配像素着色器作为输入的结构。 我们使用相同的结构代码。
请注意，SV_POSITION语义已从主要参数列表的右侧移至VS_OUTPUT结构中的pos变量的右侧。 SV_POSITION语义是系统语义。 顶点着色器必须返回顶点的位置（与SV_POSITION语义相关联），以便下一个流水线阶段（例如，光栅化器）可以读取该顶点。 然后，光栅化阶段将在多边形表面（或线）上插入顶点属性。
我们的顶点着色器仍然非常非常简单。 我们要做的就是创建一个VS_OUTPUT对象，用传递到顶点着色器中的位置和颜色填充它。

struct VS_INPUT
{
    float3 pos : POSITION;
    float4 color: COLOR;
};

struct VS_OUTPUT
{
    float4 pos: SV_POSITION;
    float4 color: COLOR;
};

VS_OUTPUT main(VS_INPUT input)
{
    VS_OUTPUT output;
    output.pos = float4(input.pos, 1.0f);
    output.color = input.color;
    return output;
}

像素着色器

像素着色器必须返回与SV_TARGET语义相关联的float4。 SV_语义是系统值语义，并且由管道使用。
顶点属性（本教程中的颜色）在三角形表面上插值。 内插的值将传递给该三角形中每个像素的像素着色器。 在本教程中，我们要做的就是从像素着色器返回插值的颜色。

struct VS_OUTPUT
{
    float4 pos: SV_POSITION;
    float4 color: COLOR;
};

float4 main(VS_OUTPUT input) : SV_TARGET
{
    // return interpolated color
    return input.color;
}

这就是添加颜色的全部，希望您能学到一些知识〜

源代码
VertexShader.hlsl

struct VS_INPUT
{
    float3 pos : POSITION;
    float4 color: COLOR;
};

struct VS_OUTPUT
{
    float4 pos: SV_POSITION;
    float4 color: COLOR;
};

VS_OUTPUT main(VS_INPUT input)
{
    VS_OUTPUT output;
    output.pos = float4(input.pos, 1.0f);
    output.color = input.color;
    return output;
}

PixelShader.hlsl

struct VS_OUTPUT
{
    float4 pos: SV_POSITION;
    float4 color: COLOR;
};

float4 main(VS_OUTPUT input) : SV_TARGET
{
    // return interpolated color
    return input.color;
}

stdafx.h

#pragma once

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN    // Exclude rarely-used stuff from Windows headers.
#endif

#include <windows.h>
#include <d3d12.h>
#include <dxgi1_4.h>
#include <D3Dcompiler.h>
#include <DirectXMath.h>
#include "d3dx12.h"
#include <string>

// this will only call release if an object exists (prevents exceptions calling release on non existant objects)
#define SAFE_RELEASE(p) { if ( (p) ) { (p)->Release(); (p) = 0; } }

// Handle to the window
HWND hwnd = NULL;

// name of the window (not the title)
LPCTSTR WindowName = L"BzTutsApp";

// title of the window
LPCTSTR WindowTitle = L"Bz Window";

// width and height of the window
int Width = 800;
int Height = 600;

// is window full screen?
bool FullScreen = false;

// we will exit the program when this becomes false
bool Running = true;

// create a window
bool InitializeWindow(HINSTANCE hInstance,
    int ShowWnd,
    bool fullscreen);

// main application loop
void mainloop();

// callback function for windows messages
LRESULT CALLBACK WndProc(HWND hWnd,
    UINT msg,
    WPARAM wParam,
    LPARAM lParam);

// direct3d stuff
const int frameBufferCount = 3; // number of buffers we want, 2 for double buffering, 3 for tripple buffering

ID3D12Device* device; // direct3d device

IDXGISwapChain3* swapChain; // swapchain used to switch between render targets

ID3D12CommandQueue* commandQueue; // container for command lists

ID3D12DescriptorHeap* rtvDescriptorHeap; // a descriptor heap to hold resources like the render targets

ID3D12Resource* renderTargets[frameBufferCount]; // number of render targets equal to buffer count

ID3D12CommandAllocator* commandAllocator[frameBufferCount]; // we want enough allocators for each buffer * number of threads (we only have one thread)

ID3D12GraphicsCommandList* commandList; // a command list we can record commands into, then execute them to render the frame

ID3D12Fence* fence[frameBufferCount];    // an object that is locked while our command list is being executed by the gpu. We need as many 
                                         //as we have allocators (more if we want to know when the gpu is finished with an asset)

HANDLE fenceEvent; // a handle to an event when our fence is unlocked by the gpu

UINT64 fenceValue[frameBufferCount]; // this value is incremented each frame. each fence will have its own value

int frameIndex; // current rtv we are on

int rtvDescriptorSize; // size of the rtv descriptor on the device (all front and back buffers will be the same size)
                       // function declarations

bool InitD3D(); // initializes direct3d 12

void Update(); // update the game logic

void UpdatePipeline(); // update the direct3d pipeline (update command lists)

void Render(); // execute the command list

void Cleanup(); // release com ojects and clean up memory

void WaitForPreviousFrame(); // wait until gpu is finished with command list

ID3D12PipelineState* pipelineStateObject; // pso containing a pipeline state

ID3D12RootSignature* rootSignature; // root signature defines data shaders will access

D3D12_VIEWPORT viewport; // area that output from rasterizer will be stretched to.

D3D12_RECT scissorRect; // the area to draw in. pixels outside that area will not be drawn onto

ID3D12Resource* vertexBuffer; // a default buffer in GPU memory that we will load vertex data for our triangle into

D3D12_VERTEX_BUFFER_VIEW vertexBufferView; // a structure containing a pointer to the vertex data in gpu memory
                        // the total size of the buffer, and the size of each element (vertex)

main.cpp

#include "stdafx.h"

using namespace DirectX; // we will be using the directxmath library

struct Vertex {
    Vertex(float x, float y, float z, float r, float g, float b, float a) : pos(x, y, z), color(r, g, b, z) {}
    XMFLOAT3 pos;
    XMFLOAT4 color;
};

int WINAPI WinMain(HINSTANCE hInstance,    //Main windows function
    HINSTANCE hPrevInstance,
    LPSTR lpCmdLine,
    int nShowCmd)

{
    // create the window
    if (!InitializeWindow(hInstance, nShowCmd, FullScreen))
    {
        MessageBox(0, L"Window Initialization - Failed",
            L"Error", MB_OK);
        return 1;
    }

    // initialize direct3d
    if (!InitD3D())
    {
        MessageBox(0, L"Failed to initialize direct3d 12",
            L"Error", MB_OK);
        Cleanup();
        return 1;
    }

    // start the main loop
    mainloop();

    // we want to wait for the gpu to finish executing the command list before we start releasing everything
    WaitForPreviousFrame();

    // close the fence event
    CloseHandle(fenceEvent);

    // clean up everything
    Cleanup();

    return 0;
}

// create and show the window
bool InitializeWindow(HINSTANCE hInstance,
    int ShowWnd,
    bool fullscreen)

{
    if (fullscreen)
    {
        HMONITOR hmon = MonitorFromWindow(hwnd,
            MONITOR_DEFAULTTONEAREST);
        MONITORINFO mi = { sizeof(mi) };
        GetMonitorInfo(hmon, &mi);

        Width = mi.rcMonitor.right - mi.rcMonitor.left;
        Height = mi.rcMonitor.bottom - mi.rcMonitor.top;
    }

    WNDCLASSEX wc;

    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = NULL;
    wc.cbWndExtra = NULL;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 2);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = WindowName;
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    if (!RegisterClassEx(&wc))
    {
        MessageBox(NULL, L"Error registering class",
            L"Error", MB_OK | MB_ICONERROR);
        return false;
    }

    hwnd = CreateWindowEx(NULL,
        WindowName,
        WindowTitle,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT,
        Width, Height,
        NULL,
        NULL,
        hInstance,
        NULL);

    if (!hwnd)
    {
        MessageBox(NULL, L"Error creating window",
            L"Error", MB_OK | MB_ICONERROR);
        return false;
    }

    if (fullscreen)
    {
        SetWindowLong(hwnd, GWL_STYLE, 0);
    }

    ShowWindow(hwnd, ShowWnd);
    UpdateWindow(hwnd);

    return true;
}

void mainloop() {
    MSG msg;
    ZeroMemory(&msg, sizeof(MSG));

    while (Running)
    {
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            if (msg.message == WM_QUIT)
                break;

            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else {
            // run game code
            Update(); // update the game logic
            Render(); // execute the command queue (rendering the scene is the result of the gpu executing the command lists)
        }
    }
}

LRESULT CALLBACK WndProc(HWND hwnd,
    UINT msg,
    WPARAM wParam,
    LPARAM lParam)

{
    switch (msg)
    {
    case WM_KEYDOWN:
        if (wParam == VK_ESCAPE) {
            if (MessageBox(0, L"Are you sure you want to exit?",
                L"Really?", MB_YESNO | MB_ICONQUESTION) == IDYES)
            {
                Running = false;
                DestroyWindow(hwnd);
            }
        }
        return 0;

    case WM_DESTROY: // x button on top right corner of window was pressed
        Running = false;
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd,
        msg,
        wParam,
        lParam);
}

bool InitD3D()
{
    HRESULT hr;

    // -- Create the Device -- //

    IDXGIFactory4* dxgiFactory;
    hr = CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory));
    if (FAILED(hr))
    {
        return false;
    }

    IDXGIAdapter1* adapter; // adapters are the graphics card (this includes the embedded graphics on the motherboard)

    int adapterIndex = 0; // we'll start looking for directx 12  compatible graphics devices starting at index 0

    bool adapterFound = false; // set this to true when a good one was found

                               // find first hardware gpu that supports d3d 12
    while (dxgiFactory->EnumAdapters1(adapterIndex, &adapter) != DXGI_ERROR_NOT_FOUND)
    {
        DXGI_ADAPTER_DESC1 desc;
        adapter->GetDesc1(&desc);

        if (desc.Flags & DXGI_ADAPTER_FLAG_SOFTWARE)
        {
            // we dont want a software device
            continue;
        }

        // we want a device that is compatible with direct3d 12 (feature level 11 or higher)
        hr = D3D12CreateDevice(adapter, D3D_FEATURE_LEVEL_11_0, _uuidof(ID3D12Device), nullptr);
        if (SUCCEEDED(hr))
        {
            adapterFound = true;
            break;
        }

        adapterIndex++;
    }

    if (!adapterFound)
    {
        return false;
    }

    // Create the device
    hr = D3D12CreateDevice(
        adapter,
        D3D_FEATURE_LEVEL_11_0,
        IID_PPV_ARGS(&device)
        );
    if (FAILED(hr))
    {
        return false;
    }

    // -- Create a direct command queue -- //

    D3D12_COMMAND_QUEUE_DESC cqDesc = {};
    cqDesc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
    cqDesc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT; // direct means the gpu can directly execute this command queue

    hr = device->CreateCommandQueue(&cqDesc, IID_PPV_ARGS(&commandQueue)); // create the command queue
    if (FAILED(hr))
    {
        return false;
    }

    // -- Create the Swap Chain (double/tripple buffering) -- //

    DXGI_MODE_DESC backBufferDesc = {}; // this is to describe our display mode
    backBufferDesc.Width = Width; // buffer width
    backBufferDesc.Height = Height; // buffer height
    backBufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM; // format of the buffer (rgba 32 bits, 8 bits for each chanel)

                                                        // describe our multi-sampling. We are not multi-sampling, so we set the count to 1 (we need at least one sample of course)
    DXGI_SAMPLE_DESC sampleDesc = {};
    sampleDesc.Count = 1; // multisample count (no multisampling, so we just put 1, since we still need 1 sample)

                          // Describe and create the swap chain.
    DXGI_SWAP_CHAIN_DESC swapChainDesc = {};
    swapChainDesc.BufferCount = frameBufferCount; // number of buffers we have
    swapChainDesc.BufferDesc = backBufferDesc; // our back buffer description
    swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT; // this says the pipeline will render to this swap chain
    swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_DISCARD; // dxgi will discard the buffer (data) after we call present
    swapChainDesc.OutputWindow = hwnd; // handle to our window
    swapChainDesc.SampleDesc = sampleDesc; // our multi-sampling description
    swapChainDesc.Windowed = !FullScreen; // set to true, then if in fullscreen must call SetFullScreenState with true for full screen to get uncapped fps

    IDXGISwapChain* tempSwapChain;

    dxgiFactory->CreateSwapChain(
        commandQueue, // the queue will be flushed once the swap chain is created
        &swapChainDesc, // give it the swap chain description we created above
        &tempSwapChain // store the created swap chain in a temp IDXGISwapChain interface
        );

    swapChain = static_cast<IDXGISwapChain3*>(tempSwapChain);

    frameIndex = swapChain->GetCurrentBackBufferIndex();

    // -- Create the Back Buffers (render target views) Descriptor Heap -- //

    // describe an rtv descriptor heap and create
    D3D12_DESCRIPTOR_HEAP_DESC rtvHeapDesc = {};
    rtvHeapDesc.NumDescriptors = frameBufferCount; // number of descriptors for this heap.
    rtvHeapDesc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV; // this heap is a render target view heap

                                                       // This heap will not be directly referenced by the shaders (not shader visible), as this will store the output from the pipeline
                                                       // otherwise we would set the heap's flag to D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE
    rtvHeapDesc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
    hr = device->CreateDescriptorHeap(&rtvHeapDesc, IID_PPV_ARGS(&rtvDescriptorHeap));
    if (FAILED(hr))
    {
        return false;
    }

    // get the size of a descriptor in this heap (this is a rtv heap, so only rtv descriptors should be stored in it.
    // descriptor sizes may vary from device to device, which is why there is no set size and we must ask the 
    // device to give us the size. we will use this size to increment a descriptor handle offset
    rtvDescriptorSize = device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);

    // get a handle to the first descriptor in the descriptor heap. a handle is basically a pointer,
    // but we cannot literally use it like a c++ pointer.
    CD3DX12_CPU_DESCRIPTOR_HANDLE rtvHandle(rtvDescriptorHeap->GetCPUDescriptorHandleForHeapStart());

    // Create a RTV for each buffer (double buffering is two buffers, tripple buffering is 3).
    for (int i = 0; i < frameBufferCount; i++)
    {
        // first we get the n'th buffer in the swap chain and store it in the n'th
        // position of our ID3D12Resource array
        hr = swapChain->GetBuffer(i, IID_PPV_ARGS(&renderTargets[i]));
        if (FAILED(hr))
        {
            return false;
        }

        // the we "create" a render target view which binds the swap chain buffer (ID3D12Resource[n]) to the rtv handle
        device->CreateRenderTargetView(renderTargets[i], nullptr, rtvHandle);

        // we increment the rtv handle by the rtv descriptor size we got above
        rtvHandle.Offset(1, rtvDescriptorSize);
    }

    // -- Create the Command Allocators -- //

    for (int i = 0; i < frameBufferCount; i++)
    {
        hr = device->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&commandAllocator[i]));
        if (FAILED(hr))
        {
            return false;
        }
    }

    // -- Create a Command List -- //

    // create the command list with the first allocator
    hr = device->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, commandAllocator[frameIndex], NULL, IID_PPV_ARGS(&commandList));
    if (FAILED(hr))
    {
        return false;
    }

    // -- Create a Fence & Fence Event -- //

    // create the fences
    for (int i = 0; i < frameBufferCount; i++)
    {
        hr = device->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&fence[i]));
        if (FAILED(hr))
        {
            return false;
        }
        fenceValue[i] = 0; // set the initial fence value to 0
    }

    // create a handle to a fence event
    fenceEvent = CreateEvent(nullptr, FALSE, FALSE, nullptr);
    if (fenceEvent == nullptr)
    {
        return false;
    }

    // create root signature

    CD3DX12_ROOT_SIGNATURE_DESC rootSignatureDesc;
    rootSignatureDesc.Init(0, nullptr, 0, nullptr, D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT);

    ID3DBlob* signature;
    hr = D3D12SerializeRootSignature(&rootSignatureDesc, D3D_ROOT_SIGNATURE_VERSION_1, &signature, nullptr);
    if (FAILED(hr))
    {
        return false;
    }

    hr = device->CreateRootSignature(0, signature->GetBufferPointer(), signature->GetBufferSize(), IID_PPV_ARGS(&rootSignature));
    if (FAILED(hr))
    {
        return false;
    }

    // create vertex and pixel shaders

    // when debugging, we can compile the shader files at runtime.
    // but for release versions, we can compile the hlsl shaders
    // with fxc.exe to create .cso files, which contain the shader
    // bytecode. We can load the .cso files at runtime to get the
    // shader bytecode, which of course is faster than compiling
    // them at runtime

    // compile vertex shader
    ID3DBlob* vertexShader; // d3d blob for holding vertex shader bytecode
    ID3DBlob* errorBuff; // a buffer holding the error data if any
    hr = D3DCompileFromFile(L"VertexShader.hlsl",
        nullptr,
        nullptr,
        "main",
        "vs_5_0",
        D3DCOMPILE_DEBUG | D3DCOMPILE_SKIP_OPTIMIZATION,
        0,
        &vertexShader,
        &errorBuff);
    if (FAILED(hr))
    {
        OutputDebugStringA((char*)errorBuff->GetBufferPointer());
        return false;
    }

    // fill out a shader bytecode structure, which is basically just a pointer
    // to the shader bytecode and the size of the shader bytecode
    D3D12_SHADER_BYTECODE vertexShaderBytecode = {};
    vertexShaderBytecode.BytecodeLength = vertexShader->GetBufferSize();
    vertexShaderBytecode.pShaderBytecode = vertexShader->GetBufferPointer();

    // compile pixel shader
    ID3DBlob* pixelShader;
    hr = D3DCompileFromFile(L"PixelShader.hlsl",
        nullptr,
        nullptr,
        "main",
        "ps_5_0",
        D3DCOMPILE_DEBUG | D3DCOMPILE_SKIP_OPTIMIZATION,
        0,
        &pixelShader,
        &errorBuff);
    if (FAILED(hr))
    {
        OutputDebugStringA((char*)errorBuff->GetBufferPointer());
        return false;
    }

    // fill out shader bytecode structure for pixel shader
    D3D12_SHADER_BYTECODE pixelShaderBytecode = {};
    pixelShaderBytecode.BytecodeLength = pixelShader->GetBufferSize();
    pixelShaderBytecode.pShaderBytecode = pixelShader->GetBufferPointer();

    // create input layout

    // The input layout is used by the Input Assembler so that it knows
    // how to read the vertex data bound to it.

    D3D12_INPUT_ELEMENT_DESC inputLayout[] =
    {
        { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
        { "COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 }
    };

    // fill out an input layout description structure
    D3D12_INPUT_LAYOUT_DESC inputLayoutDesc = {};

    // we can get the number of elements in an array by "sizeof(array) / sizeof(arrayElementType)"
    inputLayoutDesc.NumElements = sizeof(inputLayout) / sizeof(D3D12_INPUT_ELEMENT_DESC);
    inputLayoutDesc.pInputElementDescs = inputLayout;

    // create a pipeline state object (PSO)

    // In a real application, you will have many pso's. for each different shader
    // or different combinations of shaders, different blend states or different rasterizer states,
    // different topology types (point, line, triangle, patch), or a different number
    // of render targets you will need a pso

    // VS is the only required shader for a pso. You might be wondering when a case would be where
    // you only set the VS. It's possible that you have a pso that only outputs data with the stream
    // output, and not on a render target, which means you would not need anything after the stream
    // output.

    D3D12_GRAPHICS_PIPELINE_STATE_DESC psoDesc = {}; // a structure to define a pso
    psoDesc.InputLayout = inputLayoutDesc; // the structure describing our input layout
    psoDesc.pRootSignature = rootSignature; // the root signature that describes the input data this pso needs
    psoDesc.VS = vertexShaderBytecode; // structure describing where to find the vertex shader bytecode and how large it is
    psoDesc.PS = pixelShaderBytecode; // same as VS but for pixel shader
    psoDesc.PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE; // type of topology we are drawing
    psoDesc.RTVFormats[0] = DXGI_FORMAT_R8G8B8A8_UNORM; // format of the render target
    psoDesc.SampleDesc = sampleDesc; // must be the same sample description as the swapchain and depth/stencil buffer
    psoDesc.SampleMask = 0xffffffff; // sample mask has to do with multi-sampling. 0xffffffff means point sampling is done
    psoDesc.RasterizerState = CD3DX12_RASTERIZER_DESC(D3D12_DEFAULT); // a default rasterizer state.
    psoDesc.BlendState = CD3DX12_BLEND_DESC(D3D12_DEFAULT); // a default blent state.
    psoDesc.NumRenderTargets = 1; // we are only binding one render target

    // create the pso
    hr = device->CreateGraphicsPipelineState(&psoDesc, IID_PPV_ARGS(&pipelineStateObject));
    if (FAILED(hr))
    {
        return false;
    }

    // Create vertex buffer

    // a triangle
    Vertex vList[] = {
        { 0.0f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f },
        { 0.5f, -0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f },
        { -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f },
    };

    int vBufferSize = sizeof(vList);

    // create default heap
    // default heap is memory on the GPU. Only the GPU has access to this memory
    // To get data into this heap, we will have to upload the data using
    // an upload heap
    device->CreateCommittedResource(
        &CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_DEFAULT), // a default heap
        D3D12_HEAP_FLAG_NONE, // no flags
        &CD3DX12_RESOURCE_DESC::Buffer(vBufferSize), // resource description for a buffer
        D3D12_RESOURCE_STATE_COPY_DEST, // we will start this heap in the copy destination state since we will copy data
                                        // from the upload heap to this heap
        nullptr, // optimized clear value must be null for this type of resource. used for render targets and depth/stencil buffers
        IID_PPV_ARGS(&vertexBuffer));

    // we can give resource heaps a name so when we debug with the graphics debugger we know what resource we are looking at
    vertexBuffer->SetName(L"Vertex Buffer Resource Heap");

    // create upload heap
    // upload heaps are used to upload data to the GPU. CPU can write to it, GPU can read from it
    // We will upload the vertex buffer using this heap to the default heap
    ID3D12Resource* vBufferUploadHeap;
    device->CreateCommittedResource(
        &CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_UPLOAD), // upload heap
        D3D12_HEAP_FLAG_NONE, // no flags
        &CD3DX12_RESOURCE_DESC::Buffer(vBufferSize), // resource description for a buffer
        D3D12_RESOURCE_STATE_GENERIC_READ, // GPU will read from this buffer and copy its contents to the default heap
        nullptr,
        IID_PPV_ARGS(&vBufferUploadHeap));
    vBufferUploadHeap->SetName(L"Vertex Buffer Upload Resource Heap");

    // store vertex buffer in upload heap
    D3D12_SUBRESOURCE_DATA vertexData = {};
    vertexData.pData = reinterpret_cast<BYTE*>(vList); // pointer to our vertex array
    vertexData.RowPitch = vBufferSize; // size of all our triangle vertex data
    vertexData.SlicePitch = vBufferSize; // also the size of our triangle vertex data

    // we are now creating a command with the command list to copy the data from
    // the upload heap to the default heap
    UpdateSubresources(commandList, vertexBuffer, vBufferUploadHeap, 0, 0, 1, &vertexData);

    // transition the vertex buffer data from copy destination state to vertex buffer state
    commandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(vertexBuffer, D3D12_RESOURCE_STATE_COPY_DEST, D3D12_RESOURCE_STATE_VERTEX_AND_CONSTANT_BUFFER));

    // Now we execute the command list to upload the initial assets (triangle data)
    commandList->Close();
    ID3D12CommandList* ppCommandLists[] = { commandList };
    commandQueue->ExecuteCommandLists(_countof(ppCommandLists), ppCommandLists);

    // increment the fence value now, otherwise the buffer might not be uploaded by the time we start drawing
    fenceValue[frameIndex]++;
    hr = commandQueue->Signal(fence[frameIndex], fenceValue[frameIndex]);
    if (FAILED(hr))
    {
        Running = false;
    }

    // create a vertex buffer view for the triangle. We get the GPU memory address to the vertex pointer using the GetGPUVirtualAddress() method
    vertexBufferView.BufferLocation = vertexBuffer->GetGPUVirtualAddress();
    vertexBufferView.StrideInBytes = sizeof(Vertex);
    vertexBufferView.SizeInBytes = vBufferSize;

    // Fill out the Viewport
    viewport.TopLeftX = 0;
    viewport.TopLeftY = 0;
    viewport.Width = Width;
    viewport.Height = Height;
    viewport.MinDepth = 0.0f;
    viewport.MaxDepth = 1.0f;

    // Fill out a scissor rect
    scissorRect.left = 0;
    scissorRect.top = 0;
    scissorRect.right = Width;
    scissorRect.bottom = Height;

    return true;
}

void Update()
{
    // update app logic, such as moving the camera or figuring out what objects are in view
}

void UpdatePipeline()
{
    HRESULT hr;

    // We have to wait for the gpu to finish with the command allocator before we reset it
    WaitForPreviousFrame();

    // we can only reset an allocator once the gpu is done with it
    // resetting an allocator frees the memory that the command list was stored in
    hr = commandAllocator[frameIndex]->Reset();
    if (FAILED(hr))
    {
        Running = false;
    }

    // reset the command list. by resetting the command list we are putting it into
    // a recording state so we can start recording commands into the command allocator.
    // the command allocator that we reference here may have multiple command lists
    // associated with it, but only one can be recording at any time. Make sure
    // that any other command lists associated to this command allocator are in
    // the closed state (not recording).
    // Here you will pass an initial pipeline state object as the second parameter,
    // but in this tutorial we are only clearing the rtv, and do not actually need
    // anything but an initial default pipeline, which is what we get by setting
    // the second parameter to NULL
    hr = commandList->Reset(commandAllocator[frameIndex], pipelineStateObject);
    if (FAILED(hr))
    {
        Running = false;
    }

    // here we start recording commands into the commandList (which all the commands will be stored in the commandAllocator)

    // transition the "frameIndex" render target from the present state to the render target state so the command list draws to it starting from here
    commandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(renderTargets[frameIndex], D3D12_RESOURCE_STATE_PRESENT, D3D12_RESOURCE_STATE_RENDER_TARGET));

    // here we again get the handle to our current render target view so we can set it as the render target in the output merger stage of the pipeline
    CD3DX12_CPU_DESCRIPTOR_HANDLE rtvHandle(rtvDescriptorHeap->GetCPUDescriptorHandleForHeapStart(), frameIndex, rtvDescriptorSize);

    // set the render target for the output merger stage (the output of the pipeline)
    commandList->OMSetRenderTargets(1, &rtvHandle, FALSE, nullptr);

    // Clear the render target by using the ClearRenderTargetView command
    const float clearColor[] = { 0.0f, 0.2f, 0.4f, 1.0f };
    commandList->ClearRenderTargetView(rtvHandle, clearColor, 0, nullptr);

    // draw triangle
    commandList->SetGraphicsRootSignature(rootSignature); // set the root signature
    commandList->RSSetViewports(1, &viewport); // set the viewports
    commandList->RSSetScissorRects(1, &scissorRect); // set the scissor rects
    commandList->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST); // set the primitive topology
    commandList->IASetVertexBuffers(0, 1, &vertexBufferView); // set the vertex buffer (using the vertex buffer view)
    commandList->DrawInstanced(3, 1, 0, 0); // finally draw 3 vertices (draw the triangle)

    // transition the "frameIndex" render target from the render target state to the present state. If the debug layer is enabled, you will receive a
    // warning if present is called on the render target when it's not in the present state
    commandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(renderTargets[frameIndex], D3D12_RESOURCE_STATE_RENDER_TARGET, D3D12_RESOURCE_STATE_PRESENT));

    hr = commandList->Close();
    if (FAILED(hr))
    {
        Running = false;
    }
}

void Render()
{
    HRESULT hr;

    UpdatePipeline(); // update the pipeline by sending commands to the commandqueue

    // create an array of command lists (only one command list here)
    ID3D12CommandList* ppCommandLists[] = { commandList };

    // execute the array of command lists
    commandQueue->ExecuteCommandLists(_countof(ppCommandLists), ppCommandLists);

    // this command goes in at the end of our command queue. we will know when our command queue 
    // has finished because the fence value will be set to "fenceValue" from the GPU since the command
    // queue is being executed on the GPU
    hr = commandQueue->Signal(fence[frameIndex], fenceValue[frameIndex]);
    if (FAILED(hr))
    {
        Running = false;
    }

    // present the current backbuffer
    hr = swapChain->Present(0, 0);
    if (FAILED(hr))
    {
        Running = false;
    }
}

void Cleanup()
{
    // wait for the gpu to finish all frames
    for (int i = 0; i < frameBufferCount; ++i)
    {
        frameIndex = i;
        WaitForPreviousFrame();
    }

    // get swapchain out of full screen before exiting
    BOOL fs = false;
    if (swapChain->GetFullscreenState(&fs, NULL))
        swapChain->SetFullscreenState(false, NULL);

    SAFE_RELEASE(device);
    SAFE_RELEASE(swapChain);
    SAFE_RELEASE(commandQueue);
    SAFE_RELEASE(rtvDescriptorHeap);
    SAFE_RELEASE(commandList);

    for (int i = 0; i < frameBufferCount; ++i)
    {
        SAFE_RELEASE(renderTargets[i]);
        SAFE_RELEASE(commandAllocator[i]);
        SAFE_RELEASE(fence[i]);
    };

    SAFE_RELEASE(pipelineStateObject);
    SAFE_RELEASE(rootSignature);
    SAFE_RELEASE(vertexBuffer);
}

void WaitForPreviousFrame()
{
    HRESULT hr;

    // swap the current rtv buffer index so we draw on the correct buffer
    frameIndex = swapChain->GetCurrentBackBufferIndex();

    // if the current fence value is still less than "fenceValue", then we know the GPU has not finished executing
    // the command queue since it has not reached the "commandQueue->Signal(fence, fenceValue)" command
    if (fence[frameIndex]->GetCompletedValue() < fenceValue[frameIndex])
    {
        // we have the fence create an event which is signaled once the fence's current value is "fenceValue"
        hr = fence[frameIndex]->SetEventOnCompletion(fenceValue[frameIndex], fenceEvent);
        if (FAILED(hr))
        {
            Running = false;
        }

        // We will wait until the fence has triggered the event that it's current value has reached "fenceValue". once it's value
        // has reached "fenceValue", we know the command queue has finished executing
        WaitForSingleObject(fenceEvent, INFINITE);
    }

    // increment fenceValue for next frame
    fenceValue[frameIndex]++;
}

 

参考链接：

1. https://docs.microsoft.com/en-us/windows/win32/direct3d12/directx-12-programming-guide
2. http://www.d3dcoder.net/
3. https://www.braynzarsoft.net/viewtutorial/q16390-04-directx-12-braynzar-soft-tutorials
4. https://developer.nvidia.com/dx12-dos-and-donts
5. https://www.3dgep.com/learning-directx-12-1/
6. https://gpuopen.com/learn/lets-learn-directx12/
7. https://alain.xyz/blog/raw-directx12
8. https://www.rastertek.com/tutdx12.html
9. https://digitalerr0r.net/2015/08/19/quickstart-directx-12-programming/
10. https://walbourn.github.io/getting-started-with-direct3d-12/
11. https://docs.aws.amazon.com/lumberyard/latest/userguide/graphics-rendering-directx.html
12. http://diligentgraphics.com/diligent-engine/samples/
13. https://www.programmersought.com/article/2904113865/
14. https://www.tutorialspoint.com/directx/directx_first_hlsl.htm
15. http://rbwhitaker.wikidot.com/hlsl-tutorials
16. https://digitalerr0r.net/2015/08/19/quickstart-directx-12-programming/
17. https://www.ronja-tutorials.com/post/002-hlsl/

 

标签：return,渲染,hr,false,buffer,添加,command,D3D12,三角形
来源： https://blog.51cto.com/u_15273495/2915353

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