Provided by: opengl-4-man-doc_1.0~svn33624-3_all 
NAME
fwidth - return the sum of the absolute value of derivatives in x and y
DECLARATION
genType fwidth(genType p);
genType fwidthCoarse(genType p);
genType fwidthFine(genType p);
PARAMETERS
p
Specifies the expression of which to take the partial derivative.
DESCRIPTION
Available only in the fragment shader, these functions return the sum of the absolute derivatives in $x$
and $y$ using local differencing for the input argument p. fwidth is equivalent to abs(dFdx(p)) +
abs(dFdy(p)). fwidthCoarse is equivalent to abs(dFdxCoarse(p)) + abs(dFdyCoarse(p)). fwidthFine is
equivalent to abs(dFdxFine(p)) + abs(dFdyFine(p)).
VERSION SUPPORT
┌──────────────┬───────────────────────────────────────────────────────────────────────────────────┐
│ │ OpenGL Shading Language Version │
├──────────────┼──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┤
│Function │ 1.10 │ 1.20 │ 1.30 │ 1.40 │ 1.50 │ 3.30 │ 4.00 │ 4.10 │ 4.20 │ 4.30 │ 4.40 │ 4.50 │
│Name │ │ │ │ │ │ │ │ │ │ │ │ │
├──────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
│fwidth │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │
├──────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
│fwidthCoarse, │ - │ - │ - │ - │ - │ - │ - │ - │ - │ - │ - │ ✔ │
│fwidthFine │ │ │ │ │ │ │ │ │ │ │ │ │
└──────────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘
SEE ALSO
dFdx()
COPYRIGHT
Copyright © 2011-2014 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/.
COPYRIGHT
Copyright © 2011-2014 Khronos Group [FIXME: source] 11/18/2024 FWIDTH(3G)