| Name |
| |
| OES_matrix_get |
| |
| Name Strings |
| |
| GL_OES_matrix_get |
| |
| Contact |
| |
| Aaftab Munshi (amunshi@ati.com) |
| |
| Notice |
| |
| Copyright (c) 2004-2013 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, Aug 5, 2004. |
| |
| Version |
| |
| Last Modified Date: July 16, 2004 |
| |
| Number |
| |
| OpenGL ES Extension #11 |
| |
| Dependencies |
| |
| OpenGL 1.5 is required |
| |
| Overview |
| |
| Many applications require the ability to be able to read the |
| GL matrices. OpenGL ES 1.1 will allow an application to read |
| the matrices using the GetFloatv command for the common profile |
| and the GetFixedv command for the common-lite profile. |
| |
| In cases where the common-lite implementation stores matrices |
| and performs matrix operations internally using floating pt |
| (example would be OpenGL ES implementations that support JSR184 etc.) |
| the GL cannot return the floating pt matrix elements since the float |
| data type is not supported by the common-lite profile. |
| Using GetFixedv to get the matrix data will result in a loss of |
| information. |
| |
| To take care of this issue, new tokens are proposed by this |
| extension. These tokens will allow the GL to return a |
| representation of the floating pt matrix elements as as an array |
| of integers, according to the IEEE 754 floating pt "single format" |
| bit layout. |
| |
| Bit 31 represents the sign of the floating pt number. |
| Bits 30 - 23 represent the exponent of the floating pt number. |
| Bits 22 - 0 represent the mantissa of the floating pt number. |
| |
| IP Status |
| |
| There is no intellectual property associated with this extension. |
| |
| Issues |
| |
| None known. |
| |
| New Procedures and Functions |
| |
| |
| New Tokens |
| |
| Accepted by the <pname> parameter of GetIntegerv: |
| |
| MODELVIEW_MATRIX_FLOAT_AS_INT_BITS_OES 0x898d |
| PROJECTION_MATRIX_FLOAT_AS_INT_BITS_OES 0x898e |
| TEXTURE_MATRIX_FLOAT_AS_INT_BITS_OES 0x898f |
| |
| Additions to Chapter 2 of the OpenGL 1.4 Specification (OpenGL Operation) |
| |
| None. |
| |
| Additions to Chapter 3 of the OpenGL 1.4 Specification (Rasterization) |
| |
| None. |
| |
| Additions to Chapter 4 of the OpenGL 1.4 Specification (Per-Fragment |
| Operations and the Frame Buffer) |
| |
| None. |
| |
| Additions to Chapter 5 of the OpenGL 1.4 Specification (Special |
| Functions) |
| |
| None. |
| |
| Additions to Chapter 6 of the OpenGL 1.4 Specification (State and |
| State Requests) |
| |
| The new matrix tokens return the matrix elements as exponent |
| and mantissa terms. These tokens will allow the GL to return a |
| representation of the floating pt matrix elements as as an array |
| of integers, according to the IEEE 754 floating pt "single format" |
| bit layout. |
| |
| Errors |
| |
| None. |
| |
| New State |
| |
| |
| Get Value Type Command Value |
| --------- ---- ------- ------- |
| MODELVIEW_MATRIX_FLOAT_AS_INT_BITS_OES 4* x 4* x Z GetIntegerv 0 |
| PROJECTION_MATRIX_FLOAT_AS_INT_BITS_OES 4* x 4* x Z GetIntegerv 0 |
| TEXTURE_MATRIX_FLOAT_AS_INT_BITS_OES 4* x 4* x Z GetIntegerv 0 |
| |
| |
| Revision History |
| |
| |
| June 30, 2004 Aaftab Munshi Initial version of document |
| July 16, 2004 Aaftab Munshi Removed the description of NaN & denorms |
| |