DirectX11 C ++着色器緩沖區在多邊形布局描述中變為null

Question

我正在使用DX11開發游戲引擎。 我的問題是我得到一個讀取訪問沖突，因為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

當代碼到達polygonLayout[3].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA; ，緩沖區設置為正常。 但是在該行（ polygonLayout[3].InstanceDataStepRate = 0; ）之后，該值變為null ，沒有任何polygonLayout[3].InstanceDataStepRate = 0;原因，

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

拋出異常的行。

我嘗試在線搜索沒有結果。 任何幫助深表感謝。 提前致謝。

Answer 1

polygonLayout數組只包含3個項目，因此當您填充polygonLayout[3]您將產生緩沖區溢出並面臨未定義的行為（可能會破壞存儲在堆棧中的其他變量）。 1）使它包含4個項目是個好主意; 2）使用數組包裝器（debug）索引檢查：

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