EXT_read_format_bgra
Name
EXT_read_format_bgra
Name Strings
GL_EXT_read_format_bgra
Notice
Copyright Imagination Technologies Limited, 2005 - 2009.
Contact
Imagination Technologies (devtech 'at' imgtec 'dot' com)
Status
Complete
Version
1.1, 26 October 2009
Number
OpenGL ES Extension #66
Dependencies
GL_OES_read_format or OpenGL ES 1.1 or 2.0 is required
The extension is written against the OpenGLES 1.0 Specification,
which in turn is based OpenGL 1.3. Thus this spec is effectively
written against OpenGL 1.3 but does not address sections explicitly
removed or reduced by OpenGL-ES 1.0.
Overview
This extension is intended to supplement the GL_OES_read_format
extension by adding support for more format/type combinations to be used
when calling ReadPixels. ReadPixels currently accepts one fixed
format/type combination (format RGBA and type UNSIGNED_BYTE) for
portability, and an implementation specific format/type combination
queried using the tokens IMPLEMENTATION_COLOR_READ_FORMAT_OES and
IMPLEMENTATION_COLOR_READ_TYPE_OES (GL_OES_read_format extension). This
extension adds the following format/type combinations to those currently
allowed to be returned by GetIntegerV:
format type
------ ----
BGRA_EXT UNSIGNED_BYTE
BGRA_EXT UNSIGNED_SHORT_4_4_4_4_REV_EXT
BGRA_EXT UNSIGNED_SHORT_1_5_5_5_REV_EXT
E.g. Calling GetIntegerv with a <pname> parameter of
IMPLEMENTATION_COLOR_READ_FORMAT_OES can now return BGRA_EXT, with the
corresponding call to GetIntegerv using a <pname> parameter of
IMPLEMENTATION_COLOR_READ_TYPE_OES returning UNSIGNED_BYTE;
IP Status
Unknown
Issues
None.
New Procedures and Functions
None.
New Tokens
Accepted by the <format> parameter of ReadPixels:
GL_BGRA_EXT 0x80E1
Accepted by the <type> parameter of ReadPixels:
GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT 0x8365
GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT 0x8366
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)
None
Errors
None
New State
None
New Implementation Dependent State
None
Revision History
1.0, 04/06/2009 bcb: Tidied for publication.
1.1, 10/26/2009 Benj Lipchak: Add suffixes to overview text.