fwidth
Returns the absolute value of the partial derivatives of the specified value.
| ret fwidth(x) |
|---|
This function computes the following: abs(ddx(x)) + abs(ddy(x)).
This function is only supported in pixel shaders.
Parameters
| Item | Description |
|---|---|
| x |
[in] The specified value. |
Return Value
The absolute value of the partial derivatives of the x parameter.
Type Description
| Name | Template Type | Component Type | Size |
|---|---|---|---|
| x | scalar, vector, or matrix | float | any |
| ret | same as input x | float | same dimension(s) as input x |
Minimum Shader Model
This function is supported in the following shader models.
| Shader Model | Supported |
|---|---|
| Shader Model 3 (DirectX HLSL) and higher shader models | yes |
| Shader Model 2 (DirectX HLSL) | yes (ps_2_x only) |
| Shader Model 1 (DirectX HLSL) | no |