Name

    WGL_ARB_extensions_string

Name Strings

    WGL_ARB_extensions_string

Contact

    Paula Womack, NVIDIA, pwomack 'at' nvidia.com

Status

    Complete. Approved by ARB on March 15, 2000

Version

    Last Modified Date: March 12, 2002
    Author Revision: 1.1

Number

    ARB Extension #8

Dependencies

    None

Overview

    This extension provides a way for applications to determine which
    WGL extensions are supported by a device. This is the foundation
    upon which other WGL extensions are built.

IP Status

    No issues.

Issues

  1. Note that extensions that were previously advertised via
     glGetString (e.g., the swap interval extension) should continue to
     be advertised there so existing applications don't break. They
     should also be advertised via wglGetExtensionsStringARB so new
     applications can make one call to find out which WGL extensions are
     supported.

  2. Should this function take an hdc? It seems like a good idea. At
     some point MS may want to incorporate this into OpenGL32. If they
     do this and and they want to support more than one ICD, then an HDC
     would be needed.

New Procedures and Functions

    const char *wglGetExtensionsStringARB(HDC hdc);

New Tokens

    None

Additions to Chapter 2 of the 1.2 Specification (OpenGL Operation)

    None

Additions to Chapter 3 of the 1.2 Specification (Rasterization)

    None

Additions to Chapter 4 of the 1.2 Specification (Per-Fragment Operations
and the Frame buffer)

    None

Additions to Chapter 5 of the 1.2 Specification (Special Functions)

    None

Additions to Chapter 6 of the 1.2 Specification (State and State Requests)

    None

Additions to the WGL Specification

Advertising WGL Extensions

    Applications should call wglGetProcAddress to see whether or not
    wglGetExtensionsStringARB is supported. If it is supported then it
    can be used to determine which WGL extensions are supported by the
    device.

      const char *wglGetExtensionsStringARB(HDC hdc);

      <hdc>   device context to query extensions for

    If the function succeeds, it returns a list of supported extensions
    to WGL. Although the contents of the string is implementation
    specific, the string will be NULL terminated and will contain a
    space-separated list of extension names. (The extension names
    themselves do not contain spaces.) If there are no extensions then
    the empty string is returned.

    If <hdc> does not indicate a valid device context then the function
    fails and the error ERROR_DC_NOT_FOUND is generated. If the function
    fails, the return value is NULL. To get extended error information,
    call GetLastError.

New State

    None

New Implementation Dependent State

    None

Revision History

    Changes from EXT_extension_string:

    Added hdc parameter to facilitate moving this function into OPENGL32
    Added WGL to name to avoid name collisions with GL and GLX

    03/12/2002	1.1
	- Updated contact information.