Name

dFdx, dFdy — return the partial derivative of an argument with respect to x or y

Declaration

genType dFdx(genType p);
 
genType dFdy(genType p);
 

Parameters

p

Specifies the expression of which to take the partial derivative.

Description

Available only in the fragment shader, dFdx and dFdy return the partial derivative of expression p in x and y, respectively. Deviatives are calculated using local differencing. Expressions that imply higher order derivatives such as dFdx(dFdx(n)) have undefined results, as do mixed-order derivatives such as dFdx(dFdy(n)). It is assumed that the expression p is continuous and therefore, expressions evaluated via non-uniform control flow may be undefined.

Version Support

OpenGL ES Shading Language Version
Function Name 1.00 3.00
dFdx-✔
dFdy-✔

See Also

fwidth

Copyright

Copyright © 2011-2013 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999.