'\" t
.\"     Title: fwidth
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 01/03/2018
.\"    Manual: [FIXME: manual]
.\"    Source: [FIXME: source]
.\"  Language: English
.\"
.TH "FWIDTH" "3G" "01/03/2018" "[FIXME: source]" "[FIXME: manual]"
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.SH "NAME"
fwidth \- return the sum of the absolute value of derivatives in x and y
.SH "DECLARATION"
.HP \w'genType\ fwidth('u
.BI "genType fwidth(genType\ " "p" ");"
.HP \w'genType\ fwidthCoarse('u
.BI "genType fwidthCoarse(genType\ " "p" ");"
.HP \w'genType\ fwidthFine('u
.BI "genType fwidthFine(genType\ " "p" ");"
.SH "PARAMETERS"
.PP
\fIp\fR
.RS 4
Specifies the expression of which to take the partial derivative\&.
.RE
.SH "DESCRIPTION"
.PP
\fIAvailable only in the fragment shader\fR, these functions return the sum of the absolute derivatives in $x$ and $y$ using local differencing for the input argument
\fIp\fR\&.
\fBfwidth\fR
is equivalent to
\fBabs\fR(\fIdFdx\fR(p)) + \fBabs\fR(\fIdFdy\fR(p))\&.
\fBfwidthCoarse\fR
is equivalent to
\fBabs\fR(\fIdFdxCoarse\fR(p)) + \fBabs\fR(\fIdFdyCoarse\fR(p))\&.
\fBfwidthFine\fR
is equivalent to
\fBabs\fR(\fIdFdxFine\fR(p)) + \fBabs\fR(\fIdFdyFine\fR(p))\&.
.SH "VERSION SUPPORT"
.TS
allbox tab(:);
lB cB s s s s s s s s s s s
lB cB cB cB cB cB cB cB cB cB cB cB cB.
T{

T}:T{
\fBOpenGL Shading Language Version\fR
T}
T{
\fBFunction Name\fR
T}:T{
\fB1\&.10\fR
T}:T{
\fB1\&.20\fR
T}:T{
\fB1\&.30\fR
T}:T{
\fB1\&.40\fR
T}:T{
\fB1\&.50\fR
T}:T{
\fB3\&.30\fR
T}:T{
\fB4\&.00\fR
T}:T{
\fB4\&.10\fR
T}:T{
\fB4\&.20\fR
T}:T{
\fB4\&.30\fR
T}:T{
\fB4\&.40\fR
T}:T{
\fB4\&.50\fR
T}
.T&
l c c c c c c c c c c c c
l c c c c c c c c c c c c.
T{
fwidth
T}:T{
✔
T}:T{
✔
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✔
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✔
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✔
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✔
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✔
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✔
T}:T{
✔
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✔
T}:T{
✔
T}:T{
✔
T}
T{
fwidthCoarse, fwidthFine
T}:T{
\-
T}:T{
\-
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\-
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\-
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\-
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\-
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\-
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\-
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\-
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\-
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\-
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✔
T}
.TE
.sp 1
.SH "SEE ALSO"
.PP
\fBdFdx\fR()
.SH "COPYRIGHT"
.PP
Copyright
\(co
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\&.
\m[blue]\fBhttp://opencontent\&.org/openpub/\fR\m[]\&.
.SH "COPYRIGHT"
.br
Copyright \(co 2011-2014 Khronos Group
.br