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D3D12_SHADER_COMPONENT_MAPPING enumeration (d3d12.h)

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Specifies how memory gets routed by a shader resource view (SRV).

Syntax

typedef enum D3D12_SHADER_COMPONENT_MAPPING {
  D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_0 = 0,
  D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_1 = 1,
  D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_2 = 2,
  D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_3 = 3,
  D3D12_SHADER_COMPONENT_MAPPING_FORCE_VALUE_0 = 4,
  D3D12_SHADER_COMPONENT_MAPPING_FORCE_VALUE_1 = 5
} ;

Constants

 
D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_0
Value: 0
Indicates return component 0 (red).
D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_1
Value: 1
Indicates return component 1 (green).
D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_2
Value: 2
Indicates return component 2 (blue).
D3D12_SHADER_COMPONENT_MAPPING_FROM_MEMORY_COMPONENT_3
Value: 3
Indicates return component 3 (alpha).
D3D12_SHADER_COMPONENT_MAPPING_FORCE_VALUE_0
Value: 4
Indicates forcing the resulting value to 0.
D3D12_SHADER_COMPONENT_MAPPING_FORCE_VALUE_1
Value: 5
Indicates forcing the resulting value 1. The value of forcing 1 is either 0x1 or 1.0f depending on the format type for that component in the source format.

Remarks

This enum allows the SRV to select how memory gets routed to the four return components in a shader after a memory fetch. The options for each shader component [0..3] (corresponding to RGBA) are: component 0..3 from the SRV fetch result or force 0 or force 1.

The default 1:1 mapping can be indicated by specifying D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING, otherwise an arbitrary mapping can be specified using the macro D3D12_ENCODE_SHADER_4_COMPONENT_MAPPING.

See below.

Note the following defines.

#define D3D12_SHADER_COMPONENT_MAPPING_MASK 0x7
#define D3D12_SHADER_COMPONENT_MAPPING_SHIFT 3
#define D3D12_SHADER_COMPONENT_MAPPING_ALWAYS_SET_BIT_AVOIDING_ZEROMEM_MISTAKES \
    (1<<(D3D12_SHADER_COMPONENT_MAPPING_SHIFT*4))
#define D3D12_ENCODE_SHADER_4_COMPONENT_MAPPING(Src0,Src1,Src2,Src3) \
    ((((Src0)&D3D12_SHADER_COMPONENT_MAPPING_MASK)| \
    (((Src1)&D3D12_SHADER_COMPONENT_MAPPING_MASK)<<D3D12_SHADER_COMPONENT_MAPPING_SHIFT)| \
    (((Src2)&D3D12_SHADER_COMPONENT_MAPPING_MASK)<<(D3D12_SHADER_COMPONENT_MAPPING_SHIFT*2))| \
    (((Src3)&D3D12_SHADER_COMPONENT_MAPPING_MASK)<<(D3D12_SHADER_COMPONENT_MAPPING_SHIFT*3))| \
    D3D12_SHADER_COMPONENT_MAPPING_ALWAYS_SET_BIT_AVOIDING_ZEROMEM_MISTAKES))
#define D3D12_DECODE_SHADER_4_COMPONENT_MAPPING(ComponentToExtract,Mapping) \
    ((D3D12_SHADER_COMPONENT_MAPPING)(Mapping >> (D3D12_SHADER_COMPONENT_MAPPING_SHIFT*ComponentToExtract) & D3D12_SHADER_COMPONENT_MAPPING_MASK))
#define D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING D3D12_ENCODE_SHADER_4_COMPONENT_MAPPING(0,1,2,3)

Requirements

Requirement Value
Header d3d12.h

See also

Core enumerations