GatherCmpAlpha(S,float,float,int,uint) function

Samples a texture, tests the samples against a compare value, and returns the alpha component along with status about the operation.

Syntax

TemplateType GatherCmpAlpha(
  _In_  SamplerState S,
  _In_  float        Location,
  _In_  float        CompareValue,
  _In_  int          Offset,
  _Out_ uint         Status
);

Parameters

S [in]

Type: SamplerState

The zero-based sampler index.

Location [in]

Type: float

The sample coordinates (u,v).

CompareValue [in]

Type: float

A value to compare each against each sampled value.

Offset [in]

Type: int

The offset applied to the texture coordinates before sampling.

Status [out]

Type: uint

The status of the operation. You can't access the status directly; instead, pass the status to the CheckAccessFullyMapped intrinsic function. CheckAccessFullyMapped returns TRUE if all values from the corresponding Sample, Gather, or Load operation accessed mapped tiles in a tiled resource. If any values were taken from an unmapped tile, CheckAccessFullyMapped returns FALSE.

Return value

Type: TemplateType

A four-component value whose type is the same as the template type.

Remarks

The texture samples can be used for bilinear interpolation.

This function is supported for the following types of shaders:

Vertex Hull Domain Geometry Pixel Compute
x x x x x x

 

See also

GatherCmpAlpha methods