DirectX11 C++ 着色器缓冲区在多边形布局描述中变为空

Posted 2023-02-22

【中文标题】DirectX11 C++ 着色器缓冲区在多边形布局描述中变为空

【英文标题】：DirectX11 C++ Shader Buffer becomes null on polygon layout description

【发布时间】：2017-11-26 11:24:23

【问题描述】：

我正在使用 DX11 开发游戏引擎。我的问题是我遇到了读取访问冲突，因为 vertexShaderBuffer 是 nullptr。

bool TerrainShaderClass::InitializeShader(ID3D11Device* device, HWND hwnd, LPCSTR vsFileName, LPCSTR psFileName)

    HRESULT result;
    ID3D10Blob* errorMessage = nullptr;
    ID3D10Blob* vertexShaderBuffer = nullptr;
    ID3D10Blob* pixelShaderBuffer = nullptr;
    D3D11_INPUT_ELEMENT_DESC polygonLayout[3];
    unsigned int numElements;
    D3D11_SAMPLER_DESC samplerDesc;
    D3D11_BUFFER_DESC matrixBufferDesc;
    D3D11_BUFFER_DESC lightBufferDesc;


    result = D3DX11CompileFromFile(vsFileName, NULL, NULL, "TerrainVertexShader", "vs_5_0", D3D10_SHADER_ENABLE_STRICTNESS, 0, NULL,
        &vertexShaderBuffer, &errorMessage, NULL);
    if (FAILED(result))
    
        if (errorMessage)
        
            OutputShaderErrorMessage(errorMessage, hwnd, vsFileName);
        
        else
        
            MessageBox(hwnd, vsFileName, "Missing Shader File", MB_OK);
        

        return false;
    

    result = D3DX11CompileFromFile(psFileName, NULL, NULL, "TerrainPixelShader", "ps_5_0", D3D10_SHADER_ENABLE_STRICTNESS, 0, NULL,
        &pixelShaderBuffer, &errorMessage, NULL);
    if (FAILED(result))
    
        if (errorMessage)
        
            OutputShaderErrorMessage(errorMessage, hwnd, psFileName);
        
        else
        
            MessageBox(hwnd, psFileName, "Missing Shader File", MB_OK);
        

        return false;
    

    result = device->CreateVertexShader(vertexShaderBuffer->GetBufferPointer(), vertexShaderBuffer->GetBufferSize(), NULL,
        &m_vertexShader);
    if (FAILED(result))
    
        return false;
    

    result = device->CreatePixelShader(pixelShaderBuffer->GetBufferPointer(), pixelShaderBuffer->GetBufferSize(), NULL,
        &m_pixelShader);
    if (FAILED(result))
    
        return false;
    

    // This setup needs to match the VertexType stucture in the ModelClass and in the shader.
    polygonLayout[0].SemanticName = "POSITION";
    polygonLayout[0].SemanticIndex = 0;
    polygonLayout[0].Format = DXGI_FORMAT_R32G32B32_FLOAT;
    polygonLayout[0].InputSlot = 0;
    polygonLayout[0].AlignedByteOffset = 0;
    polygonLayout[0].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
    polygonLayout[0].InstanceDataStepRate = 0;

    polygonLayout[1].SemanticName = "TEXCOORD";
    polygonLayout[1].SemanticIndex = 0;
    polygonLayout[1].Format = DXGI_FORMAT_R32G32_FLOAT;
    polygonLayout[1].InputSlot = 0;
    polygonLayout[1].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;
    polygonLayout[1].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
    polygonLayout[1].InstanceDataStepRate = 0;

    polygonLayout[2].SemanticName = "NORMAL";
    polygonLayout[2].SemanticIndex = 0;
    polygonLayout[2].Format = DXGI_FORMAT_R32G32B32_FLOAT;
    polygonLayout[2].InputSlot = 0;
    polygonLayout[2].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;
    polygonLayout[2].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
    polygonLayout[2].InstanceDataStepRate = 0;

    polygonLayout[3].SemanticName = "COLOR";
    polygonLayout[3].SemanticIndex = 0;
    polygonLayout[3].Format = DXGI_FORMAT_R32G32B32_FLOAT;
    polygonLayout[3].InputSlot = 0;
    polygonLayout[3].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;
    polygonLayout[3].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
    polygonLayout[3].InstanceDataStepRate = 0;

    numElements = sizeof(polygonLayout) / sizeof(polygonLayout[0]);

    result = device->CreateInputLayout(polygonLayout, numElements, vertexShaderBuffer->GetBufferPointer(),
        vertexShaderBuffer->GetBufferSize(), &m_layout);

    if (FAILED(result))
    
        return false;
    

    vertexShaderBuffer->Release();
    vertexShaderBuffer = nullptr;

    pixelShaderBuffer->Release();
    pixelShaderBuffer = nullptr;
//Continues

当代码到达polygonLayout[3].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA; 时，缓冲区设置为正常。但在那一行 (polygonLayout[3].InstanceDataStepRate = 0;) 之后，值变为null，没有明显的原因，带有

result = device->CreateInputLayout(polygonLayout, numElements, vertexShaderBuffer->GetBufferPointer(),
            vertexShaderBuffer->GetBufferSize(), &m_layout);

抛出异常的行。

我尝试在线搜索但没有结果。任何帮助深表感谢。提前致谢。

【参考方案1】：

polygonLayout 数组仅包含 3 个项目，因此当您填充 polygonLayout[3] 时，您将产生缓冲区溢出并面临未定义行为（可能会破坏存储在堆栈中的其他变量）。 1) 让它包含 4 个项目是个好主意； 2) 使用带有（调试）索引检查的数组包装器：

::std::array<D3D11_INPUT_ELEMENT_DESC, 4> polygonLayout;