Class RootSignature

Synopsis

#include <Source/Falcor/Core/API/RootSignature.h>

class dlldecl RootSignature

Description

The root signature defines what resources are bound to the pipeline.

The layout is defined by traversing the ParameterBlock hierarchy of a program to find all required root parameters. These are then arranged consecutively in the following order in the root signature:

descriptor tables
root descriptors
root constants

The get*BaseIndex() functions return the base index of the corresponding root parameter type in the root signature.

Classes

	Desc
	RootConstantsDesc
	RootDescriptorDesc

Methods

	RootSignature
	~RootSignature
	apiInit
	bindForCompute
	bindForGraphics
	create	Create a root signature.
	createLocal	Create a local root signature for use with DXR.
	getApiHandle
	getDesc
	getDescriptorSet
	getDescriptorSetBaseIndex
	getDescriptorSetCount
	getElementByteOffset
	getEmpty	Get an empty root signature.
	getRootConstantBaseIndex
	getRootDescriptorBaseIndex
	getSizeInBytes

Source

Lines 50-162 in Source/Falcor/Core/API/RootSignature.h.

class dlldecl RootSignature
{
public:
    using SharedPtr = std::shared_ptr<RootSignature>;
    using SharedConstPtr = std::shared_ptr<const RootSignature>;
    using ApiHandle = RootSignatureHandle;
    using DescType = Falcor::DescriptorSet::Type;
    using DescriptorSetLayout = DescriptorSet::Layout;
    struct RootDescriptorDesc
    {
        DescType type;
        uint32_t regIndex;
        uint32_t spaceIndex;
        ShaderVisibility visibility;
    };
    struct RootConstantsDesc
    {
        uint32_t regIndex;
        uint32_t spaceIndex;
        uint32_t count;
    };
    class dlldecl Desc
    {
    public:
        Desc& addDescriptorSet(const DescriptorSetLayout& setLayout);
        Desc& addRootDescriptor(DescType type, uint32_t regIndex, uint32_t spaceIndex, ShaderVisibility visibility = ShaderVisibility::All);
        Desc& addRootConstants(uint32_t regIndex, uint32_t spaceIndex, uint32_t count); // #SHADER_VAR Make sure this works with the reflectors
ef FALCOR_D3D12
        Desc& setLocal(bool isLocal) { mIsLocal = isLocal; return *this; }
if
        size_t getSetsCount() const { return mSets.size(); }
        const DescriptorSetLayout& getSet(size_t index) const { return mSets[index]; }
        size_t getRootDescriptorCount() const { return mRootDescriptors.size(); }
        const RootDescriptorDesc& getRootDescriptorDesc(size_t index) const { return mRootDescriptors[index]; }
        size_t getRootConstantCount() const { return mRootConstants.size(); }
        const RootConstantsDesc& getRootConstantDesc(size_t index) const { return mRootConstants[index]; }
    private:
        friend class RootSignature;
        std::vector<DescriptorSetLayout> mSets;
        std::vector<RootDescriptorDesc> mRootDescriptors;
        std::vector<RootConstantsDesc> mRootConstants;
ef FALCOR_D3D12
        bool mIsLocal = false;
if
    };
    ~RootSignature();
    /** Get an empty root signature.
        \return Empty root signature, or throws an exception on error.
    */
    static SharedPtr getEmpty();
    /** Create a root signature.
        \param[in] desc Root signature description.
        \return New object, or throws an exception if creation failed.
    */
    static SharedPtr create(const Desc& desc);
    /** Create a root signature from program reflection.
        \param[in] pReflection Reflection object.
        \return New object, or throws an exception if creation failed.
    */
    static SharedPtr create(const ProgramReflection* pReflection);
    /** Create a local root signature for use with DXR.
        \param[in] pReflection Reflection object.
        \return New object, or throws an exception if creation failed.
    */
    static SharedPtr createLocal(const EntryPointGroupReflection* pReflector);
    const ApiHandle& getApiHandle() const { return mApiHandle; }
    size_t getDescriptorSetCount() const { return mDesc.mSets.size(); }
    const DescriptorSetLayout& getDescriptorSet(size_t index) const { return mDesc.mSets[index]; }
    uint32_t getDescriptorSetBaseIndex() const { return 0; }
    uint32_t getRootDescriptorBaseIndex() const { return getDescriptorSetBaseIndex() + (uint32_t)mDesc.mSets.size(); }
    uint32_t getRootConstantBaseIndex() const { return getRootDescriptorBaseIndex() + (uint32_t)mDesc.mRootDescriptors.size(); }
    uint32_t getSizeInBytes() const { return mSizeInBytes; }
    uint32_t getElementByteOffset(uint32_t elementIndex) { return mElementByteOffset[elementIndex]; }
    void bindForGraphics(CopyContext* pCtx);
    void bindForCompute(CopyContext* pCtx);
    const Desc& getDesc() const { return mDesc; }
protected:
    RootSignature(const Desc& desc);
    void apiInit();
ef FALCOR_D3D12
    virtual void createApiHandle(ID3DBlobPtr pSigBlob);
if
    ApiHandle mApiHandle;
    Desc mDesc;
    static SharedPtr spEmptySig;
    static uint64_t sObjCount;
    uint32_t mSizeInBytes;
    std::vector<uint32_t> mElementByteOffset;
};