KHR_platform_wayland

Name

KHR_platform_wayland

Name Strings

EGL_KHR_platform_wayland

Contributors

Chad Versace <chad.versace@intel.com>
Jon Leech (oddhack 'at' sonic.net)

Contacts

Chad Versace <chad.versace@intel.com>

Status

Complete.
Approved by the EGL Working Group on January 31, 2014.
Ratified by the Khronos Board of Promoters on March 14, 2014. 

Version

Version 2, 2014/02/18

Number

EGL Extension #70

Extension Type

EGL client extension

Dependencies

EGL 1.5 is required.

This extension is written against the EGL 1.5 Specification (draft
20140122).

Overview

This extension defines how to create EGL resources from native Wayland
resources using the EGL 1.5 platform functionality.

New Types

None

New Procedures and Functions

None

New Tokens

Accepted as the <platform> argument of eglGetPlatformDisplay:

    EGL_PLATFORM_WAYLAND_KHR                0x31D8

Additions to the EGL Specification

None.

New Behavior

To determine if the EGL implementation supports this extension, clients
should query the EGL_EXTENSIONS string of EGL_NO_DISPLAY.

To obtain an EGLDisplay backed by a Wayland display, call
eglGetPlatformDisplay with <platform> set to EGL_PLATFORM_WAYLAND_KHR.  The
<native_display> parameter specifies the Wayland display  to use and must
either point to a `struct wl_display` or be EGL_DEFAULT_DISPLAY. If
<native_display> is EGL_DEFAULT_DISPLAY, then EGL will create a new
wl_display structure by connecting to the default Wayland socket.  The
manual page wl_display_connect(3) defines the location of the default
Wayland socket.

To obtain an on-screen rendering surface from a Wayland window, call
eglCreatePlatformWindowSurface with a <dpy> that belongs to Wayland and
a <native_window> that points to a `struct wl_egl_surface`.

It is not valid to call eglCreatePlatformPixmapSurface with a <dpy> that
belongs to Wayland. Any such call fails and generates an
EGL_BAD_PARAMETER error.

Issues

1. Should this extension permit EGL_DEFAULT_DISPLAY as input to
   eglGetPlatformDisplay()?

   RESOLUTION: Yes. When given EGL_DEFAULT_DISPLAY, eglGetPlatformDisplay
   returns a display backed by the default Wayland display.

2. Should this extension support creation of EGLPixmap resources from
   Wayland pixmaps?

   RESOLVED. No. Wayland has no pixmap type.

Revision History

Version 2, 2014/02/18 (Chad Versace)
    - Change resolution of issue #1 from "no" to "yes". Now
      eglGetPlatformDisplay accepts EGL_DEFAULT_DISPLAY for Wayland.
    - Explain in more detail how EGL connects to the default Wayland
      display.

Version 1, 2014/01/22 (Jon Leech)
    - Promote EGL_EXT_platform_wayland to KHR to go with EGL 1.5.