Name

    ANDROID_recordable

Name Strings

    EGL_ANDROID_recordable

Contributors

    Jamie Gennis

Contact

    Jamie Gennis, Google Inc. (jgennis 'at' google.com)

Status

    Draft.

Version

    Version 1, July 8, 2011

Number

    EGL Extension #XXX

Dependencies

    Requires EGL 1.0

    This extension is written against the wording of the EGL 1.4 Specification

Overview

    Android supports a number of different ANativeWindow implementations that
    can be used to create an EGLSurface.  One implementation, which records the
    rendered image as a video each time eglSwapBuffers gets called, may have
    some device-specific restrictions.  Because of this, some EGLConfigs may be
    incompatible with these ANativeWindows.  This extension introduces a new
    boolean EGLConfig attribute that indicates whether the EGLConfig supports
    rendering to an ANativeWindow that records images to a video.

New Types

    None.

New Procedures and Functions

    None.

New Tokens

    Accepted by the <attribute> parameter of eglGetConfigAttrib and
    the <attrib_list> parameter of eglChooseConfig:

        EGL_RECORDABLE_ANDROID                      0xXXXX

Changes to Chapter 3 of the EGL 1.4 Specification (EGL Functions and Errors)

    Section 3.4, Configuration Management, add a row to Table 3.1.
    
              Attribute             Type                 Notes
        ----------------------     -------     --------------------------
        EGL_RECORDABLE_ANDROID     boolean     whether video recording is
                                               supported

    Section 3.4, Configuration Management, add a row to Table 3.4.

              Attribute            Default     Selection  Sort   Sort
                                               Criteria   Order  Priority
        ----------------------  -------------  ---------  -----  --------
        EGL_RECORDABLE_ANDROID  EGL_DONT_CARE    Exact    None

    Section 3.4, Configuration Management, add a paragraph at the end of the
    subsection titled Other EGLConfig Attribute Descriptions.

        EGL_RECORDABLE_ANDROID is a boolean indicating whether the config may
        be used to create an EGLSurface from an ANativeWindow that is a video
        recorder as indicated by the NATIVE_WINDOW_IS_VIDEO_RECORDER query on
        the ANativeWindow.

    Section 3.4.1, Querying Configurations, change the last paragraph as follow

        EGLConfigs are not sorted with respect to the parameters
        EGL_BIND_TO_TEXTURE_RGB, EGL_BIND_TO_TEXTURE_RGBA, EGL_CONFORMANT,
        EGL_LEVEL, EGL_NATIVE_RENDERABLE, EGL_MAX_SWAP_INTERVAL,
        EGL_MIN_SWAP_INTERVAL, EGL_RENDERABLE_TYPE, EGL_SURFACE_TYPE,
        EGL_TRANSPARENT_TYPE, EGL_TRANSPARENT_RED_VALUE,
        EGL_TRANSPARENT_GREEN_VALUE, EGL_TRANSPARENT_BLUE_VALUE, and
        EGL_RECORDABLE_ANDROID.

Issues

    1. Should this functionality be exposed as a new attribute or as a bit in
    the EGL_SURFACE_TYPE bitfield?

    RESOLVED: It should be a new attribute.  It does not make sense to use up a
    bit in the limit-size bitfield for a platform-specific extension.

    2. How should the new attribute affect the sorting of EGLConfigs?

    RESOLVED: It should not affect sorting.  Some implementations may not have
    any drawback associated with using a recordable EGLConfig.  Such
    implementations should not have to double-up some of their configs to  one sort earlier than .
    Implementations that do have drawbacks can use the existing caveat
    mechanism to report this drawback to the client.

Revision History

#1 (Jamie Gennis, July 8, 2011)
    - Initial draft.