---
layout: stdlib-reference
---
# fwidth\_fine
## Description
Texture filter width (fine).
Calculates the sum abs(ddx_fine(p)) + abs(ddy_fine(p)).
## Signature
/// Requires Capability Set 1:
T fwidth_fine<T>(T p)
where T : __BuiltinFloatingPointType;
/// Requires Capability Set 1:
vector<T, N> fwidth_fine<T, N:int>(vector<T, N> x)
where T : __BuiltinFloatingPointType;
/// Requires Capability Set 2:
matrix<T, N, M> fwidth_fine<T, N:int, M:int>(matrix<T, N, M> x)
where T : __BuiltinFloatingPointType;
## Generic Parameters
#### T: [\_\_BuiltinFloatingPointType](../interfaces/0_builtinfloatingpointtype-029hm/index.html)
#### N : int
#### M : int
## Parameters
#### p : [T](fwidth_fine.html#typeparam-T)
The value to sum x and y partial derivative magnitudes for.
#### x : [vector](../types/vector/index.html)\<[T](../types/vector/index.html#typeparam-T), [N](../types/vector/index.html#decl-N)\>
#### x : [matrix](../types/matrix/index.html)\<[T](../types/matrix/t-0.html), [N](../types/matrix/index.html#decl-N), [M](../types/matrix/index.html#decl-M)\>
## Return value
The sum of abs(ddx_fine(p)) and abs(ddy_fine(p)).
## Remarks
For SPIR-V, this function maps to OpFwidthFine.
## Availability and Requirements
### Capability Set 1
Defined for the following targets:
#### hlsl
Available in stages: `amplification`, `fragment`, `compute`, `mesh`, `miss`, `callable`, `closesthit`, `raygen`, `intersection`, `anyhit`.
#### glsl
Available in stages: `amplification`, `fragment`, `compute`, `mesh`, `miss`, `callable`, `closesthit`, `raygen`, `intersection`, `anyhit`.
#### spirv
Available in stages: `amplification`, `fragment`, `compute`, `mesh`, `miss`, `callable`, `closesthit`, `raygen`, `intersection`, `anyhit`.
Requires capabilities: `SPV_KHR_compute_shader_derivatives`, `spvMeshShadingEXT`.
### Capability Set 2
Defined for the following targets:
#### hlsl
Available in stages: `amplification`, `fragment`, `compute`, `mesh`, `miss`, `callable`, `closesthit`, `raygen`, `intersection`, `anyhit`.
#### glsl
Available in stages: `amplification`, `fragment`, `compute`, `mesh`, `miss`, `callable`, `closesthit`, `raygen`, `intersection`, `anyhit`.
#### spirv
Available in stages: `amplification`, `fragment`, `compute`, `mesh`, `miss`, `callable`, `closesthit`, `raygen`, `intersection`, `anyhit`.
Requires capabilities: `SPV_KHR_compute_shader_derivatives`, `spvMeshShadingEXT`.