'\" t
.\"     Title: glViewport
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\"      Date: 05/21/2015
.\"    Manual: [FIXME: manual]
.\"    Source: [FIXME: source]
.\"  Language: English
.\"
.TH "GLVIEWPORT" "3G" "05/21/2015" "[FIXME: source]" "[FIXME: manual]"
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.SH "NAME"
glViewport \- set the viewport
.SH "C SPECIFICATION"
.HP \w'void\ glViewport('u
.BI "void glViewport(GLint\ " "x" ", GLint\ " "y" ", GLsizei\ " "width" ", GLsizei\ " "height" ");"
.SH "PARAMETERS"
.PP
\fIx\fR, \fIy\fR
.RS 4
Specify the lower left corner of the viewport rectangle, in pixels\&. The initial value is (0,0)\&.
.RE
.PP
\fIwidth\fR, \fIheight\fR
.RS 4
Specify the width and height of the viewport\&. When a GL context is first attached to a window,
\fIwidth\fR
and
\fIheight\fR
are set to the dimensions of that window\&.
.RE
.SH "DESCRIPTION"
.PP
\fBglViewport\fR
specifies the affine transformation of
x
and
y
from normalized device coordinates to window coordinates\&. Let
x nd y nd
be normalized device coordinates\&. Then the window coordinates
x w y w
are computed as follows:
.PP
x w = x nd + 1 ⁢ width 2 + x
.PP
y w = y nd + 1 ⁢ height 2 + y
.PP
Viewport width and height are silently clamped to a range that depends on the implementation\&. To query this range, call
\fBglGet\fR()
with argument
\fBGL_MAX_VIEWPORT_DIMS\fR\&.
.SH "ERRORS"
.PP
\fBGL_INVALID_VALUE\fR
is generated if either
\fIwidth\fR
or
\fIheight\fR
is negative\&.
.SH "ASSOCIATED GETS"
.PP
\fBglGet\fR()
with argument
\fBGL_VIEWPORT\fR
.PP
\fBglGet\fR()
with argument
\fBGL_MAX_VIEWPORT_DIMS\fR
.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 Version\fR
T}
T{
\fBFunction / Feature Name\fR
T}:T{
\fB2\&.0\fR
T}:T{
\fB2\&.1\fR
T}:T{
\fB3\&.0\fR
T}:T{
\fB3\&.1\fR
T}:T{
\fB3\&.2\fR
T}:T{
\fB3\&.3\fR
T}:T{
\fB4\&.0\fR
T}:T{
\fB4\&.1\fR
T}:T{
\fB4\&.2\fR
T}:T{
\fB4\&.3\fR
T}:T{
\fB4\&.4\fR
T}:T{
\fB4\&.5\fR
T}
.T&
l c c c c c c c c c c c c.
T{
\fBglViewport\fR
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}
.TE
.sp
.SH "SEE ALSO"
.PP
\fBglDepthRange\fR()
.SH "COPYRIGHT"
.PP
Copyright
\(co
1991\-2006 Silicon Graphics, Inc\&. Copyright
\(co
2010\-2014 Khronos Group\&. This document is licensed under the SGI Free Software B License\&. For details, see
\m[blue]\fBhttp://oss\&.sgi\&.com/projects/FreeB/\fR\m[]\&.
.SH "COPYRIGHT"
.br
Copyright \(co 1991-2006 Silicon Graphics, Inc.
.br
Copyright \(co 2010-2014 Khronos Group
.br