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Name
OES_query_matrix
Name Strings
GL_OES_query_matrix
Contact
Kari Pulli, Nokia (kari.pulli 'at' nokia.com)
Notice
Copyright (c) 2003-2013 The Khronos Group Inc. Copyright terms at
http://www.khronos.org/registry/speccopyright.html
Specification Update Policy
Khronos-approved extension specifications are updated in response to
issues and bugs prioritized by the Khronos OpenGL ES 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
https://www.khronos.org/registry/OpenGL/docs/update_policy.php
Status
Ratified by the Khronos BOP, July 23, 2003.
Version
$Date: 2003/07/23 04:23:25 $ $Revision: 1.2 $
Number
OpenGL ES Extension #16 (formerly OpenGL Extension #296)
Dependencies
OpenGL 1.3 is required.
OES_fixed_point is required.
Overview
Many applications may need to query the contents and status of the
current matrix at least for debugging purposes, especially as the
implementations are allowed to implement matrix machinery either in
any (possibly proprietary) floating point format, or in a fixed point
format that has the range and accuracy of at least 16.16 (signed 16 bit
integer part, unsigned 16 bit fractional part).
This extension is intended to allow application to query the components
of the matrix and also their status, regardless whether the internal
representation is in fixed point or floating point.
IP Status
There is no intellectual property associated with this extension.
Issues
None known.
New Procedures and Functions
GLbitfield glQueryMatrixxOES( GLfixed mantissa[16],
GLint exponent[16] )
mantissa[16] contains the contents of the current matrix in GLfixed
format. exponent[16] contains the unbiased exponents applied to the
matrix components, so that the internal representation of component i
is close to mantissa[i] * 2^exponent[i]. The function returns a status
word which is zero if all the components are valid. If
status & (1<<i) != 0, the component i is invalid (e.g., NaN, Inf).
The implementations are not required to keep track of overflows. In
that case, the invalid bits are never set.
New Tokens
None
Additions to Chapter 2 of the OpenGL 1.3 Specification (OpenGL Operation)
None
Additions to Chapter 3 of the OpenGL 1.3 Specification (Rasterization)
None
Additions to Chapter 4 of the OpenGL 1.3 Specification (Per-Fragment
Operations and the Frame Buffer)
None
Additions to Chapter 5 of the OpenGL 1.3 Specification (Special Functions)
None
Additions to Chapter 6 of the OpenGL 1.3 Specification (State and
State Requests)
Insert Overview and New Procedures and Functions to become Section 6.1.13.
Additions to Appendix A of the OpenGL 1.3 Specification (Invariance)
None
Additions to the AGL/GLX/WGL Specifications
GLX Protocol
QueryMatrixxOES() is mapped to the equivalent protocol for
floating-point state queries. Two queries are required; one to
retrieve the current matrix mode and another to retrieve the
matrix values.
Dependencies on OES_fixed_point
OES_fixed_point is required for the GLfixed definition.
Errors
None
New State
None
New Implementation Dependent State
None
Revision History
Apr 15, 2003 Kari Pulli Created the document
Jul 08, 2003 David Blythe Clarified the Dependencies section,
Added extension number
Jul 12, 2003 David Blythe Add GLX protocol note