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Name Strings
John Kessenich, 3Dlabs, Inc. (johnk 'at'
Barthold Lichtenbelt, NVIDIA (blichtenbelt 'at'
Jon Leech, SGI (ljp 'at'
Copyright (c) 2003-2013 The Khronos Group Inc. Copyright terms at
Specification Update Policy
Khronos-approved extension specifications are updated in response to
issues and bugs prioritized by the Khronos OpenGL Working Group. For
extensions which have been promoted to a core Specification, fixes will
first appear in the latest version of that core Specification, and will
eventually be backported to the extension document. This policy is
described in more detail at
IP Status
Microsoft claims to own unspecified intellectual property related to
programmable shading.
Complete. Approved by the ARB on June 11, 2003.
Updated revision 8 approved by the ARB on June 17, 2004.
Last Modified Date: April 6, 2004
Revision: 8
ARB Extension #33
This extension is written against the OpenGL 1.5 Specification
ARB_shader_objects, ARB_fragment_shader, and ARB_vertex_shader are
required to utilize the OpenGL Shading Language associated with this
This extension string indicates that the OpenGL Shading Language is
supported. The Shading Language is defined by a separate specification
document which can be downloaded from
1) How do we indicate revisions in the supported version of the Shading
RESOLVED: Add a SHADING_LANGUAGE_VERSION query. This query was not
present in the initial version of the extension. Therefore,
applications should be prepared to detect an INVALID_ENUM error
being raised by glGetString(GL_SHADING_LANGUAGE_VERSION). If this
error is raised, but ARB_shading_language_100 is defined in the
EXTENSIONS string, the application can assume that the initial
release of the Shading Language (1.00, which was numbered "1.051"
corresponding to document revision 51) is supported.
2) What is the format of the SHADING_LANGUAGE_VERSION string? How does
it map onto the release number of the shading language specification?
RESOLVED: Identical to the VERSION string format:
"major.minor[.release] [vendor info]". The release number is an
optional vendor release number, not the shading language
specification document release number (which is never visible to
The "1.051" release number of the initial Shading Language
specification document corresponds to a SHADING_LANGUAGE_VERSION
string of "1.00", since "51" was the revision number of the
document, not the minor number.
Going forward, the specification and query must always use the same
encoding for major and minor numbers. The second release of the
specification will be labelled "version 1.10, document revision 55",
and the corresponding SHADING_LANGUAGE_VERSION string will be "1.10"
(we chose to bump the minor version directly to 10 to avoid problems
with leading 0s, and confusion with the old "1.051" document release
Document release and vendor release numbers need not have any
relation to each other, since they represent changes other than
functionality, such as bug fixes and optimizations (for the
implementation), and typos and errata for the specification).
Functional changes to the shading language must always be indicated
by an increase in the specification minor version number. Such
changes may or may not correspond to changes to the core OpenGL
version number as well, depending on whether or not they are visible
in the OpenGL API.
3) Should SHADING_LANGUAGE_VERSION be added to the state tables?
RESOLVED: Yes. The other GetString queries (VERSION, EXTENSIONS,
RENDERER, and VENDOR), which have been omitted in the past, should
also be added, along with a new type code for string state values.
4) What should the exact wording of the "IP Status" language be?
Microsoft has made claims towards the low-level vertex shader and
towards the generic programming framework proposed but not accepted
into OpenGL 1.4, although that framework did not specify an actual
shading language. Additional verbal statements made by Dave Aronson
suggest that Microsoft may feel its claims extend to all
programmable shading implementations. In fairness to implementers,
we need to note the possibility of such a claim while also noting
our lack of any specific information about what IP is being claimed.
New Tokens
Accepted by the <name> parameter of GetString:
Additions to Chapter 6 of the OpenGL 1.5 Specification (State and State
Modify Section 6.1.11, Pointer and String Queries
... returns a pointer to a static string describing some aspect of the
current GL connection(1).
{footnote 1: Applications making copies of these static strings
should never use a fixed-length buffer, because the strings may grow
unpredictably over time resulting in buffer overflow when copying.
This is particularly true of the EXTENSIONS string, which has become
extremely long in some GL implementations.}
The possible values for <name> are VENDOR, RENDERER, VERSION,
VENDOR strings is implementation dependent. The EXTENSIONS string
contains a space separated list of extension names (the extension names
themselves do not contain any spaces). The VERSION and
SHADING_LANGUAGE_VERSION strings are laid out as follows:
<version number><space><vendor-specific information>
The version number is either of the form <major_number.minor_number> or
<major_number.minor_number.release_number>, where the numbers all have
one or more digits. The <release_number> and vendor specific information
are optional. However, if present, then they pertain to the server and
their format and contents are implementation dependent.
Add to Table 6.3, State variable types
Type code Explanation
--------- ----------------------
S NULL-terminated string
The error INVALID_ENUM may be generated by GetString if <name> is
SHADING_LANGUAGE_VERSION, but only the initial version of this extension
is supported. In this case, the implementation will support the initial
release (version 1.00, document version labelled "1.051") of the OpenGL
Shading Language.
New Implementation Dependent State
Added to table 6.30 (Implementation Dependent Values)
Get Value Type Get Command Minimum Description Sec. Attrib
--------- ---- ----------- ------- ----------- ---- ------
EXTENSIONS S GetString - Supported extensions 6.1.11 -
RENDERER S GetString - Renderer string 6.1.11 -
SHADING_LANGUAGE_VERSION S GetString - Shading Language 6.1.11 -
_ARB version supported
VENDOR S GetString - Vendor string 6.1.11 -
VERSION S GetString - OpenGL version 6.1.11 -
Revision History
Date: 2004/04/06
Revision: 8
- Corrected several typos and noted an additional reason for going to
minor release number 10 instead of 1 (ambiguity relative to the
initial "1.051" document release number).
Date: 2004/04/06
Revision: 7
- Clarified that the release_number field is also vendor information,
and that the major.minor notation of the query and the shading
language specification must match in the future. Noted that not
supporting the query implies that version 1.00 of the shading
language is supported.
Date: 2004/04/05
Revision: 6
- Fixed some typos. Changed errors section to require that the initial
version of the shading language be supported if the
SHADING_LANGUAGE_VERSION query fails, but the extension is
Date: 2004/04/02
Revision: 5
- Assigned enum value to SHADING_LANGUAGE_VERSION. Corrected
Date: 2004/03/26
Revision: 4
match extension name. Added an issue to determine exact wording of
the IP Status comment.
Date: 2004/03/19
Revision: 3
- Resolved issues 2 and 3. Required that future shading language
specification version numbers match the SHADER_VERSION format.
Corrected omission of other GetString queries from the state tables.
Date: 2004/03/14
Revision: 2
- Corrected URL to refer to instead of
- Added SHADER_VERSION string query. Defined format of the shader
version string and described fallback behavior for older
implementations of the extension.