fwidth

Description

Texture filter width. Calculates the sum abs(ddx(p)) + abs(ddy(p)).

Signature

/// Requires Capability Set 1:
T fwidth<T>(T p)
    where T : __BuiltinFloatingPointType;

/// Requires Capability Set 2:
vector<T, N> fwidth<T, N:int>(vector<T, N> x)
    where T : __BuiltinFloatingPointType;

/// Requires Capability Set 3:
matrix<T, N, M> fwidth<T, N:int, M:int>(matrix<T, N, M> x)
    where T : __BuiltinFloatingPointType;

Generic Parameters

T: __BuiltinFloatingPointType

N : int

M : int

Parameters

p : T

The value to sum x and y partial derivative magnitudes for.

x : vector<T, N>

x : matrix<T, N, M>

Return value

The sum of abs(ddx(p)) and abs(ddy(p)).

Remarks

For SPIR-V, this function maps to OpFwidth.

Availability and Requirements

Capability Set 1

Defined for the following targets:

hlsl

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

glsl

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

metal

Available in fragment stage only.

wgsl

Available in fragment stage only.

spirv

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

Requires capabilities: SPV_NV_compute_shader_derivatives, spvMeshShadingEXT.

Capability Set 2

Defined for the following targets:

hlsl

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

glsl

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

wgsl

Available in fragment stage only.

spirv

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

Requires capabilities: SPV_NV_compute_shader_derivatives, spvMeshShadingEXT.

Capability Set 3

Defined for the following targets:

hlsl

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

glsl

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

spirv

Available in stages: amplification, fragment, compute, mesh, miss, callable, raygen, intersection, anyhit, closesthit.

Requires capabilities: SPV_NV_compute_shader_derivatives, spvMeshShadingEXT.