问：DX12 创建图形管道状态时出错

Question

By following the Microsoft documentation and creating the PSO, I receive the following D3D12 errors.

Error code

Considering the first error states that the encoded signature size doesn't match the specified size. I compared the shader and the signature.

    D3D12_INPUT_ELEMENT_DESC inputElementDesc[] =
    {{
      "POSITION",
      0,
      DXGI_FORMAT_R32G32B32_FLOAT,
      0,
      0,
      D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
      0
    }};

    D3D12_INPUT_LAYOUT_DESC inputLayoutDesc;
    inputLayoutDesc.pInputElementDescs = inputElementDesc;
    inputLayoutDesc.NumElements = ARRAYSIZE(inputElementDesc);

struct VSIn 
{
    float3 pos : POSITION;
};

struct VSOut
{
    float4 pos : SV_POSITION;
};

VSOut vs_main( VSIn input, uint index : SV_VertexID )
{
    VSOut output = (VSOut)0;
    output.pos = float4(input.pos, 1.0f);
    return output;
}

I cannot seem to find any wrongdoings. So I thought that maybe the fault lies within how I compiled my shaders. I used the IDxcCompiler library for this purpose. When debugging I didn't get any errors from compiling.

    ComPtr<IDxcOperationResult> result = nullptr;
    ComPtr<IDxcBlobEncoding> vertexBlob = nullptr;
    std::vector<LPCWSTR> compileArguments;
    compileArguments.push_back(L"/Gis");
    ThrowIfFailed(library->CreateBlobFromFile(L"VertexShader.hlsl", nullptr, &vertexBlob));
    ThrowIfFailed(compiler->Compile(
        vertexBlob.Get(),
        L"VertexShader.hlsl",
        L"vs_main",
        L"vs_6_4",
        compileArguments.data(),
        (UINT)compileArguments.size(),
        NULL,
        NULL,
        NULL,
        &result
    ));

And the blobs seem to have received its information

D3D12_GRAPHICS_PIPELINE_STATE_DESC gPipelineStateDesc;
gPipelineStateDesc.pRootSignature = this->gRootSignature.Get();
gPipelineStateDesc.InputLayout = inputLayoutDesc;
gPipelineStateDesc.PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE;

ComPtr<IDxcBlobEncoding> test16;
gPipelineStateDesc.VS.pShaderBytecode = reinterpret_cast<void*>(vertexBlob->GetBufferPointer());
library->GetBlobAsUtf16(vertexBlob.Get(), &test16);
OutputDebugStringW(reinterpret_cast<LPCWSTR>(test16->GetBufferPointer()));
gPipelineStateDesc.VS.BytecodeLength = vertexBlob->GetBufferSize();

gPipelineStateDesc.RTVFormats[0] = DXGI_FORMAT_R8G8B8A8_UNORM;
gPipelineStateDesc.NumRenderTargets = 1;
gPipelineStateDesc.SampleDesc.Count = 1;
gPipelineStateDesc.SampleMask = UINT_MAX;

gPipelineStateDesc.RasterizerState.FillMode = D3D12_FILL_MODE_SOLID;
gPipelineStateDesc.RasterizerState.CullMode = D3D12_CULL_MODE_BACK;

D3D12_RENDER_TARGET_BLEND_DESC RTBlendDesc = {
    false,
    false,
    D3D12_BLEND_ONE, D3D12_BLEND_ZERO, D3D12_BLEND_OP_ADD,
    D3D12_BLEND_ONE, D3D12_BLEND_ZERO, D3D12_BLEND_OP_ADD,
    D3D12_LOGIC_OP_NOOP, D3D12_COLOR_WRITE_ENABLE_ALL
};
for (UINT i = 0; i < D3D12_SIMULTANEOUS_RENDER_TARGET_COUNT; ++i)
{
    gPipelineStateDesc.BlendState.RenderTarget[i] = RTBlendDesc;
}
ThrowIfFailed(this->gDevice->CreateGraphicsPipelineState(&gPipelineStateDesc, IID_PPV_ARGS(&this->gPipelineState)));

Output Results

With a buffer size/byte code length of 241 bytes. Does anyone have any clue of what has gone wrong?

Answer 1

Chuck Walbourn Helped me find the solution. The blob did not get the results from compiling similar to D3DCompileFromFile(). By utilizing the IDxcOperationResult in the last parameter of the compiler. You are fetching the results from the compiler like this:

    ComPtr<IDxcOperationResult> result = nullptr;
    ....
    ...
    ..
    ComPtr<IDxcBlob> vertexShader = nullptr;
    result->GetResult(vertexShader);

In this way ->GetBufferPointer() should work properly. The rest of the errors were due to forgetting to initialize the pipeline state description with "={};".