D3D12_ROOT_SIGNATURE_FLAGS enumeration (d3d12.h)

Specifies options for root signature layout.

Syntax

typedef enum D3D12_ROOT_SIGNATURE_FLAGS {
  D3D12_ROOT_SIGNATURE_FLAG_NONE = 0,
  D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT = 0x1,
  D3D12_ROOT_SIGNATURE_FLAG_DENY_VERTEX_SHADER_ROOT_ACCESS = 0x2,
  D3D12_ROOT_SIGNATURE_FLAG_DENY_HULL_SHADER_ROOT_ACCESS = 0x4,
  D3D12_ROOT_SIGNATURE_FLAG_DENY_DOMAIN_SHADER_ROOT_ACCESS = 0x8,
  D3D12_ROOT_SIGNATURE_FLAG_DENY_GEOMETRY_SHADER_ROOT_ACCESS = 0x10,
  D3D12_ROOT_SIGNATURE_FLAG_DENY_PIXEL_SHADER_ROOT_ACCESS = 0x20,
  D3D12_ROOT_SIGNATURE_FLAG_ALLOW_STREAM_OUTPUT = 0x40,
  D3D12_ROOT_SIGNATURE_FLAG_LOCAL_ROOT_SIGNATURE = 0x80,
  D3D12_ROOT_SIGNATURE_FLAG_DENY_AMPLIFICATION_SHADER_ROOT_ACCESS = 0x100,
  D3D12_ROOT_SIGNATURE_FLAG_DENY_MESH_SHADER_ROOT_ACCESS = 0x200,
  D3D12_ROOT_SIGNATURE_FLAG_CBV_SRV_UAV_HEAP_DIRECTLY_INDEXED = 0x400,
  D3D12_ROOT_SIGNATURE_FLAG_SAMPLER_HEAP_DIRECTLY_INDEXED = 0x800
} ;

Constants

D3D12_ROOT_SIGNATURE_FLAG_NONE Value: 0 Indicates default behavior.
D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT Value: 0x1 The app is opting in to using the Input Assembler (requiring an input layout that defines a set of vertex buffer bindings). Omitting this flag can result in one root argument space being saved on some hardware. Omit this flag if the Input Assembler is not required, though the optimization is minor.
D3D12_ROOT_SIGNATURE_FLAG_DENY_VERTEX_SHADER_ROOT_ACCESS Value: 0x2 Denies the vertex shader access to the root signature.
D3D12_ROOT_SIGNATURE_FLAG_DENY_HULL_SHADER_ROOT_ACCESS Value: 0x4 Denies the hull shader access to the root signature.
D3D12_ROOT_SIGNATURE_FLAG_DENY_DOMAIN_SHADER_ROOT_ACCESS Value: 0x8 Denies the domain shader access to the root signature.
D3D12_ROOT_SIGNATURE_FLAG_DENY_GEOMETRY_SHADER_ROOT_ACCESS Value: 0x10 Denies the geometry shader access to the root signature.
D3D12_ROOT_SIGNATURE_FLAG_DENY_PIXEL_SHADER_ROOT_ACCESS Value: 0x20 Denies the pixel shader access to the root signature.
D3D12_ROOT_SIGNATURE_FLAG_ALLOW_STREAM_OUTPUT Value: 0x40 The app is opting in to using Stream Output. Omitting this flag can result in one root argument space being saved on some hardware. Omit this flag if Stream Output is not required, though the optimization is minor.
D3D12_ROOT_SIGNATURE_FLAG_LOCAL_ROOT_SIGNATURE Value: 0x80 The root signature is to be used with raytracing shaders to define resource bindings sourced from shader records in shader tables. This flag cannot be combined with any other root signature flags, which are all related to the graphics pipeline. The absence of the flag means the root signature can be used with graphics or compute, where the compute version is also shared with raytracing’s global root signature.
D3D12_ROOT_SIGNATURE_FLAG_DENY_AMPLIFICATION_SHADER_ROOT_ACCESS Value: 0x100 Denies the amplification shader access to the root signature.
D3D12_ROOT_SIGNATURE_FLAG_DENY_MESH_SHADER_ROOT_ACCESS Value: 0x200 Denies the mesh shader access to the root signature.
D3D12_ROOT_SIGNATURE_FLAG_CBV_SRV_UAV_HEAP_DIRECTLY_INDEXED Value: 0x400 The shaders are allowed to index the CBV/SRV/UAV descriptor heap directly, using the ResourceDescriptorHeap built-in variable.
D3D12_ROOT_SIGNATURE_FLAG_SAMPLER_HEAP_DIRECTLY_INDEXED Value: 0x800 The shaders are allowed to index the sampler descriptor heap directly, using the SamplerDescriptorHeap built-in variable.

Remarks

This enum is used in the D3D12_ROOT_SIGNATURE_DESC structure.

The value in denying access to shader stages is a minor optimization on some hardware. If, for example, the D3D12_SHADER_VISIBILITY_ALL flag has been set to broadcast the root signature to all shader stages, then denying access can overrule this and save the hardware some work. Alternatively if the shader is so simple that no root signature resources are needed, then denying access could be used here too.

Requirements

Requirement	Value
Header	d3d12.h

See also

Core Enumerations

Creating a Root Signature

D3D12_ROOT_SIGNATURE_DESC