third_party/angle/extensions/EGL_ANGLE_experimental_present_path.txt

Name

    ANGLE_experimental_present_path

Name Strings

    EGL_ANGLE_experimental_present_path

Contributors

    Austin Kinross

Contacts

    Austin Kinross (aukinros 'at' microsoft 'dot' com)

Status

    Experimental

Version

    Version 1, Jan 22 2016

Number

    EGL Extension #XXX

Extension Type

    EGL display extension

Dependencies

    Requires ANGLE_platform_angle_d3d.

    Written against the wording of EGL 1.4 as modified by
    ANGLE_platform_angle_d3d.

Overview

    This extension exposes an optimized, but potentially non-conformant,
    rendering path for ANGLE's D3D11 renderer on Windows.

New Types

    None

New Procedures and Functions

    None

New Tokens

    Accepted as an attribute name in the <attrib_list> argument of
    eglGetPlatformDisplayEXT:

        EGL_EXPERIMENTAL_PRESENT_PATH_ANGLE      0x33A4

    Accepted as values for the EGL_EXPERIMENTAL_PRESENT_PATH_ANGLE attribute:

        EGL_EXPERIMENTAL_PRESENT_PATH_FAST_ANGLE 0x33A9
        EGL_EXPERIMENTAL_PRESENT_PATH_COPY_ANGLE 0x33AA

Additions to the EGL Specification

    None.

New Behavior

    To request a display that enables this optimized rendering path,
    the value of EGL_EXPERIMENTAL_PRESENT_PATH_ANGLE should be set to
    EGL_EXPERIMENTAL_PRESENT_PATH_FAST_ANGLE. Setting this value may impact
    OpenGL ES conformance (see Issue 1 below).

    The only valid values for the attribute
    EGL_EXPERIMENTAL_PRESENT_PATH_ANGLE are
    EGL_EXPERIMENTAL_PRESENT_PATH_FAST_ANGLE and
    EGL_EXPERIMENTAL_PRESENT_PATH_COPY_ANGLE. If any other value is specified
    then an EGL_BAD_ATTRIBUTE error is generated and EGL_NO_DISPLAY is
    returned.

    If a value for EGL_EXPERIMENTAL_PRESENT_PATH_ANGLE is specified and
    EGL_PLATFORM_ANGLE_TYPE_ANGLE is not set to
    EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE then an EGL_BAD_ATTRIBUTE error is
    generated and EGL_NO_DISPLAY is returned.

	If the attribute EGL_EXPERIMENTAL_PRESENT_PATH_ANGLE
    is unspecified then it is implicitly set to
    EGL_EXPERIMENTAL_PRESENT_PATH_COPY_ANGLE.

Issues

    1) Does setting EGL_EXPERIMENTAL_PRESENT_PATH_ANGLE to be
       EGL_EXPERIMENTAL_PRESENT_PATH_FAST_ANGLE maintain OpenGL ES
       conformance?

       RESOLVED: Not necessarily, that is implementation-specific. Check then
       EGL_CONFORMANT attribute to see if the implementation supports any
       conformant EGL configs when EGL_EXPERIMENTAL_PRESENT_PATH_FAST_ANGLE
       is specified.

Revision History

    Version 1, Jan 22 2016 (Austin Kinross)
      - Initial draft