extensions/EGL_ANGLE_platform_angle_device_id.txt

Name

    ANGLE_platform_angle_device_id

Name Strings

    EGL_ANGLE_platform_angle_device_id

Contributors

    Jonah Ryan-Davis, Google
    Kimmo Kinnunen, Apple

Contacts

    Jonah Ryan-Davis, Google (jonahr 'at' google.com)

Status

    Draft

Version

    Version 2, 2022-04-09

Number

    EGL Extension XXX

Extension Type

    EGL client extension

Dependencies

    Requires ANGLE_platform_angle.

    EGL_ANGLE_display_power_preference interacts with this extension.

Overview

    This extension enables the selection of a graphics device to back
    an ANGLE EGLDisplay.

New Types

    None

New Procedures and Functions

    None

New Tokens

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

        EGL_PLATFORM_ANGLE_DEVICE_ID_HIGH_ANGLE          0x34D6
        EGL_PLATFORM_ANGLE_DEVICE_ID_LOW_ANGLE           0x34D7
        EGL_PLATFORM_ANGLE_DISPLAY_KEY_ANGLE             0x34DC

Additions to the EGL Specification

    None

New Behavior

    To request a display that is backed by a specific graphics device,
    EGL_PLATFORM_ANGLE_DEVICE_ID_HIGH_ANGLE and/or
    EGL_PLATFORM_ANGLE_DEVICE_ID_LOW_ANGLE should be set to the high part and
    low part of the device's ID. If only one attribute is specified, the other
    is assumed to be zero. The device's ID is specific to the platform that
    ANGLE is running on, but should fit into one 64-bit value.

    If the high part and low part combined is zero, an EGL_BAD_ATTRIBUTE error
    is generated and EGL_NO_DISPLAY is returned.

    If the ID specified doesn't match any devices on the system, the device
    is selected as described in the EGL_ANGLE_display_power_preference extension.

    To select a distinct display on a graphics device that may already have
    an existing display in ANGLE's cache, use EGL_PLATFORM_ANGLE_DISPLAY_KEY_ANGLE
    to add a key to the cache entry for this display. The same cached display can
    be re-requested by specifying the same cache value. If this parameter is not
    included, the default value used will be 0.

Issues

    None

Revision History

    Version 3, 2023-02-15
      - Add EGL_PLATFORM_ANGLE_DISPLAY_KEY_ANGLE to allow selection of
        multiple EGLDisplays from the same graphics device.

    Version 2, 2022-04-09 (Kimmo Kinnunen)
      - Describe interaction with EGL_ANGLE_display_power_preference,
        EGL_ANGLE_platform_angle_device_id takes precedence.

    Version 1, 2021-12-14 (Jonah Ryan-Davis)
      - Initial draft, based on EGL_ANGLE_platform_angle_d3d_luid