Name

glIntro - introduction to OpenGL ES

Overview

OpenGL ES (GL) is a 3D-oriented renderer for embedded systems.

See eglIntro for a short example program.

OpenGL Extensions

The following extensions currently exist. Note that the set of supported extensions depends on the implementation.

OES_query_matrix

provides a way to query the values of the current matrix. Each matrix value is returned as a mantissa/exponent pair. If the implementation supports tracking of invalid values, they are indicated in the returned status value.

Using OpenGL ES Extensions

Function names and tokens for OpenGL ES extensions are suffixed with OES or with a vendor-specfic acronym. OES is used for extensions that have been reviewed by the Khronos Group and might be supported by more than one OpenGL ES vendor.

All supported extensions have an associated macro definition in gl.h and a corresponding token in the extensions string returned by glGetString. For example, if the OES_query_matrix extension is supported, then the token GL_OES_query_matrix will be defined in gl.h and GL_OES_query_matrix will appear in the extensions string returned by glGetString.

The definitions in gl.h can be used at compile time to determine if an extension's tokens and procedures exist in the OpenGL ES library. However, the tokens returned by glGetString must be consulted at runtime to determine whether the extension is supported on the particular context in use at that moment.

Files

GLES/gl.h

OpenGL ES header file

Copyright

Copyright © 2003-2004 Silicon Graphics, Inc.

This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

See Also

eglIntro, glGetString