'\" t
.\"     Title: glGetProgramInterface
.\"    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 "GLGETPROGRAMINTERFAC" "3G" "01/03/2018" "[FIXME: source]" "[FIXME: manual]"
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.\" * MAIN CONTENT STARTS HERE *
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.SH "NAME"
glGetProgramInterface \- query a property of an interface in a program
.SH "C SPECIFICATION"
.HP \w'void\ glGetProgramInterfaceiv('u
.BI "void glGetProgramInterfaceiv(GLuint\ " "program" ", GLenum\ " "programInterface" ", GLenum\ " "pname" ", GLint\ *\ " "params" ");"
.SH "PARAMETERS"
.PP
\fIprogram\fR
.RS 4
The name of a program object whose interface to query\&.
.RE
.PP
\fIprogramInterface\fR
.RS 4
A token identifying the interface within
\fIprogram\fR
to query\&.
.RE
.PP
\fIpname\fR
.RS 4
The name of the parameter within
\fIprogramInterface\fR
to query\&.
.RE
.PP
\fIparams\fR
.RS 4
The address of a variable to retrieve the value of
\fIpname\fR
for the program interface\&.
.RE
.SH "DESCRIPTION"
.PP
\fBglGetProgramInterfaceiv\fR
queries the property of the interface identifed by
\fIprogramInterface\fR
in
\fIprogram\fR, the property name of which is given by
\fIpname\fR\&.
.PP
\fIprogram\fR
must be the name of an existing program object\&.
\fIprogramInterface\fR
is the name of the interface within
\fIprogram\fR
to query and must be one of the following values:
.PP
\fBGL_UNIFORM\fR
.RS 4
The query is targeted at the set of active uniforms within
\fIprogram\fR\&.
.RE
.PP
\fBGL_UNIFORM_BLOCK\fR
.RS 4
The query is targeted at the set of active uniform blocks within
\fIprogram\fR\&.
.RE
.PP
\fBGL_ATOMIC_COUNTER_BUFFER\fR
.RS 4
The query is targeted at the set of active atomic counter buffer binding points within
\fIprogram\fR\&.
.RE
.PP
\fBGL_PROGRAM_INPUT\fR
.RS 4
The query is targeted at the set of active input variables used by the first shader stage of
\fIprogram\fR\&. If
\fIprogram\fR
contains multiple shader stages then input variables from any stage other than the first will not be enumerated\&.
.RE
.PP
\fBGL_PROGRAM_OUTPUT\fR
.RS 4
The query is targeted at the set of active output variables produced by the last shader stage of
\fIprogram\fR\&. If
\fIprogram\fR
contains multiple shader stages then output variables from any stage other than the last will not be enumerated\&.
.RE
.PP
\fBGL_VERTEX_SUBROUTINE\fR, \fBGL_TESS_CONTROL_SUBROUTINE\fR, \fBGL_TESS_EVALUATION_SUBROUTINE\fR, \fBGL_GEOMETRY_SUBROUTINE\fR, \fBGL_FRAGMENT_SUBROUTINE\fR, \fBGL_COMPUTE_SUBROUTINE\fR
.RS 4
The query is targeted at the set of active subroutines for the vertex, tessellation control, tessellation evaluation, geometry, fragment and compute shader stages of
\fIprogram\fR, respectively\&.
.RE
.PP
\fBGL_VERTEX_SUBROUTINE_UNIFORM\fR, \fBGL_TESS_CONTROL_SUBROUTINE_UNIFORM\fR, \fBGL_TESS_EVALUATION_SUBROUTINE_UNIFORM\fR, \fBGL_GEOMETRY_SUBROUTINE_UNIFORM\fR, \fBGL_FRAGMENT_SUBROUTINE_UNIFORM\fR, \fBGL_COMPUTE_SUBROUTINE_UNIFORM\fR
.RS 4
The query is targeted at the set of active subroutine uniform variables used by the vertex, tessellation control, tessellation evaluation, geometry, fragment and compute shader stages of
\fIprogram\fR, respectively\&.
.RE
.PP
\fBGL_TRANSFORM_FEEDBACK_VARYING\fR
.RS 4
The query is targeted at the set of output variables from the last non\-fragment stage of
\fIprogram\fR
that would be captured if transform feedback were active\&.
.RE
.PP
\fBGL_BUFFER_VARIABLE\fR
.RS 4
The query is targeted at the set of active buffer variables used by
\fIprogram\fR\&.
.RE
.PP
\fBGL_SHADER_STORAGE_BLOCK\fR
.RS 4
The query is targeted at the set of active shader storage blocks used by
\fIprogram\fR\&.
.RE
.PP
\fBGL_TRANSFORM_FEEDBACK_BUFFER\fR
.RS 4
The query is targeted at the set of active buffer binding points to which output variables in the
\fBGL_TRANSFORM_FEEDBACK_VARYING\fR
interface are written\&.
.RE
.PP
\fIpname\fR
identifies the property of
\fIprogramInterface\fR
to return in
\fIparams\fR\&.
.PP
If
\fIpname\fR
is
\fBGL_ACTIVE_RESOURCES\fR, the value returned is the number of resources in the active resource list for
\fIprogramInterface\fR\&. If the list of active resources for
\fIprogramInterface\fR
is empty, zero is returned\&.
.PP
If
\fIpname\fR
is
\fBGL_MAX_NAME_LENGTH\fR, the value returned is the length of the longest active name string for an active resource in
\fIprogramInterface\fR\&. This length includes an extra character for the null terminator\&. If the list of active resources for
\fIprogramInterface\fR
is empty, zero is returned\&. It is an error to specify
\fBGL_MAX_NAME_LENGTH\fR
when
\fIprogramInterface\fR
is
\fBGL_ATOMIC_COUNTER_BUFFER\fR, as active atomic counter buffer resources are not assigned name strings\&.
.PP
If
\fIpname\fR
is
\fBGL_MAX_NUM_ACTIVE_VARIABLES\fR, the value returned is the number of active variables belonging to the interface block or atomic counter buffer resource in
\fIprogramInterface\fR
with the most active variables\&. If the list of active resources for
\fIprogramInterface\fR
is empty, zero is returned\&. When
\fIpname\fR
is
\fBGL_MAX_NUM_ACTIVE_VARIABLES\fR,
\fIprogramInterface\fR
must be
\fBGL_UNIFORM_BLOCK\fR,
\fBGL_ATOMIC_COUNTER_BUFFER\fR, or
\fBGL_SHADER_STORAGE_BLOCK\fR\&.
.PP
If
\fIpname\fR
is
\fBGL_MAX_NUM_COMPATIBLE_SUBROUTINES\fR, the value returned is the number of compatible subroutines belonging to the active subroutine uniform in
\fIprogramInterface\fR
with the most compatible subroutines\&. If the list of active resources for
\fIprogramInterface\fR
is empty, zero is returned\&. When
\fIpname\fR
is
\fBGL_MAX_NUM_COMPATIBLE_SUBROUTINES\fR,
\fIprogramInterface\fR
must be one of
\fBGL_VERTEX_SUBROUTINE_UNIFORM\fR,
\fBGL_TESS_CONTROL_SUBROUTINE_UNIFORM\fR,
\fBGL_TESS_EVALUATION_SUBROUTINE_UNIFORM\fR,
\fBGL_GEOMETRY_SUBROUTINE_UNIFORM\fR,
\fBGL_FRAGMENT_SUBROUTINE_UNIFORM\fR, or
\fBGL_COMPUTE_SUBROUTINE_UNIFORM\fR\&.
.SH "ERRORS"
.PP
\fBGL_INVALID_ENUM\fR
is generated if
\fIidentifier\fR
is not one of the accepted object types\&.
.PP
\fBGL_INVALID_VALUE\fR
is generated if
\fIprogram\fR
is not the name of an existing sync object\&.
.PP
\fBGL_INVALID_VALUE\fR
is generated if
\fIbufSize\fR
is zero\&.
.PP
\fBGL_INVALID_OPERATION\fR
is generated if
\fIpname\fR
is
\fBGL_MAX_NAME_LENGTH\fR
and
\fIprogramInterface\fR
is
\fBGL_ATOMIC_COUNTER_BUFFER\fR
or
\fBGL_TRANSFORM_FEEDBACK_BUFFER\fR, since active atomic counter and transform feedback buffer resources are not assigned name strings\&.
.PP
\fBGL_INVALID_OPERATION\fR
error is generated if
\fIpname\fR
is
\fBGL_MAX_NUM_ACTIVE_VARIABLES\fR
and
\fIprogramInterface\fR
is not
\fBGL_UNIFORM_BLOCK\fR,
\fBGL_SHADER_STORAGE_BLOCK\fR,
\fBGL_ATOMIC_COUNTER_BUFFER\fR, or
\fBGL_TRANSFORM_FEEDBACK_BUFFER\fR\&.
.PP
If not NULL,
\fIlength\fR
and
\fIlabel\fR
should be addresses to which the client has write access, otherwise undefined behavior, including process termination may occur\&.
.SH "ASSOCIATED GETS"
.PP
\fBglGet\fR()
with argument
\fBGL_MAX_LABEL_LENGTH\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{
\fBglGetProgramInterfaceiv\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 1
.SH "SEE ALSO"
.PP
\fBglPushDebugGroup\fR(),
\fBglPopDebugGroup\fR(),
\fBglObjectLabel\fR(),
\fBglGetObjectLabel\fR()\&.
.SH "COPYRIGHT"
.PP
Copyright
\(co
2013\-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 2013-2014 Khronos Group
.br