Method initRootSignatures

Libraries/Aurora/Source/DirectX/PTShaderLibrary.cpp:385–481

}

void PTShaderLibrary::initRootSignatures(int globalTextureCount, int globalSamplerCount)
{
    // Specify the global root signature for all shaders. This includes a global static sampler
    // which shaders can use by default, as well as dynamic samplers per-material.
    CD3DX12_DESCRIPTOR_RANGE texRange;
    CD3DX12_DESCRIPTOR_RANGE samplerRange;

    // Create the global root signature.
    // Must match the root signature data setup in PTRenderer::submitRayDispatch and the GPU
    // version in GlobalRootSignature.slang.
    array<CD3DX12_ROOT_PARAMETER, 14> globalRootParameters = {}; // NOLINT(modernize-avoid-c-arrays)
    globalRootParameters[0].InitAsShaderResourceView(0);         // gScene: acceleration structure
    globalRootParameters[1].InitAsConstants(2, 0);               // sampleIndex + seedOffset
    globalRootParameters[2].InitAsConstantBufferView(1); // gFrameData: per-frame constant buffer
    globalRootParameters[3].InitAsConstantBufferView(2); // gEnvironmentConstants
    globalRootParameters[4].InitAsShaderResourceView(1); // gEnvironmentAliasMap
    texRange.Init(D3D12_DESCRIPTOR_RANGE_TYPE_SRV, 2,
        2); // gEnvironmentLight/BackgroundTexture (starting at t2)
    CD3DX12_DESCRIPTOR_RANGE globalRootRanges[] = { texRange }; // NOLINT(modernize-avoid-c-arrays)
    globalRootParameters[5].InitAsDescriptorTable(_countof(globalRootRanges), globalRootRanges);
    globalRootParameters[6].InitAsConstantBufferView(3); // gGroundPlane
    globalRootParameters[7].InitAsShaderResourceView(4); // gNullScene: null acceleration structure
    globalRootParameters[8].InitAsShaderResourceView(
        5); // gGlobalMaterialConstants: global material constants.
    globalRootParameters[9].InitAsShaderResourceView(
        6); // gGlobalInstanceBuffer: global instance data.
    globalRootParameters[10].InitAsShaderResourceView(
        7); // gLayerGeometryBuffer: UVs for geometry layers.
    globalRootParameters[11].InitAsShaderResourceView(
        8); // gTransformMatrixBuffer: Tranform matrices for all instances.

    texRange.Init(D3D12_DESCRIPTOR_RANGE_TYPE_SRV, globalTextureCount,
        9); // gGlobalMaterialTextures: Global scene textures.
    CD3DX12_DESCRIPTOR_RANGE sceneTextureRanges[] = {
        texRange
    }; // NOLINT(modernize-avoid-c-arrays)
    globalRootParameters[12].InitAsDescriptorTable(
        _countof(sceneTextureRanges), sceneTextureRanges);

    // Sampler descriptors in gGlobalMaterialSamplers array starting at register(s0)
    samplerRange.Init(D3D12_DESCRIPTOR_RANGE_TYPE_SAMPLER, globalSamplerCount, 0);
    CD3DX12_DESCRIPTOR_RANGE globalSamplerRanges[] = {
        samplerRange
    }; // NOLINT(modernize-avoid-c-arrays)
    globalRootParameters[13].InitAsDescriptorTable(
        _countof(globalSamplerRanges), globalSamplerRanges);

    // Create the global root signature object, there are no static samplers (all the samplers
    // including default sampler are stored in gSamplerArray.)
    CD3DX12_ROOT_SIGNATURE_DESC globalDesc(
        static_cast<UINT>(globalRootParameters.size()), globalRootParameters.data(), 0, nullptr);
    _pGlobalRootSignature = createRootSignature(globalDesc);
    _pGlobalRootSignature->SetName(L"Global Root Signature");

    // Specify a local root signature for the ray gen shader.
    // The AOV descriptor count defined here must match the AOV RWTexture2Ds defined in
    // MainEntryPoints.slang. and the descriptors uploaded to the heap in
    // PTRenderer::updateOutputResources and PTRenderer::updateDenoisingResources.