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

FunctionVersion 1.10Version 1.20Version 1.30Version 1.40Version 1.50Version 3.30Version 4.00Version 4.10Version 4.20Version 4.30
dFdxYYYYYYYYYY
dFdyYYYYYYYYYY

See Also

fwidth

Copyright

Copyright © 2011 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. http://opencontent.org/openpub/.