skia / external / github.com / KhronosGroup / OpenGL-Registry / bc93187978b46e0baae0b8556071d6b292b0bb97 / . / extensions / OES / OES_query_matrix.txt

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 | |