Name
EXT_platform_wayland
Name Strings
EGL_EXT_platform_wayland
Contributors
Chad Versace <chad.versace@intel.com>
Contacts
Chad Versace <chad.versace@intel.com>
Status
Complete
Version
Version 4, 2014-03-10
Number
EGL Extension #63
Extension Type
EGL client extension
Dependencies
Requires EGL_EXT_client_extensions to query its existence without
a display.
Requires EGL_EXT_platform_base.
This extension is written against the wording of version 7 of the
EGL_EXT_platform_base specification.
Overview
This extension defines how to create EGL resources from native Wayland
resources using the functions defined by EGL_EXT_platform_base.
New Types
None
New Procedures and Functions
None
New Tokens
Accepted as the <platform> argument of eglGetPlatformDisplayEXT:
EGL_PLATFORM_WAYLAND_EXT 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
eglGetPlatformDisplayEXT with <platform> set to EGL_PLATFORM_WAYLAND_EXT. 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
eglCreatePlatformWindowSurfaceEXT 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 eglCreatePlatformPixmapSurfaceEXT with a <dpy>
that belongs to Wayland. Any such call fails and generates
EGL_BAD_PARAMETER.
Issues
1. Should this extension permit EGL_DEFAULT_DISPLAY as input to
eglGetPlatformDisplayEXT()?
RESOLUTION: Yes. When given EGL_DEFAULT_DISPLAY, eglGetPlatformDisplayEXT
returns a display backed by the default Wayland display.
2. Should this extension support creation EGLPixmap resources from Wayland
pixmaps?
RESOLVED. No. Wayland has no pixmap type.
3. Should the extension namespace be EXT or MESA?
The only shipping EGL implementation today (2013-04-26) that supports
Wayland is Mesa. However, perhaps the extension should reside in the
EXT namespace in expectation that other vendors will also begin
supporting Wayland.
RESOLVED. Use the EXT namespace because other vendors have expressed
interest in Wayland.
Revision History
Version 4, 2014-03-10(Chad Versace)
- Change resolution of issue #1 from "no" to "yes". Now
eglGetPlatformDisplayEXT accepts EGL_DEFAULT_DISPLAY for Wayland.
- Explain in more detail how EGL connects to the default Wayland
display.
Version 3, 2013-10-16 (Chad Versace)
- Resolve issue #3 to use EXT namespace.
Version 2, 2013-09-12 (Chad Versace)
- Update to wording of version 7 of EGL_EXT_platform_base spec.
- Add section "Extension Type".
- Rephrase the discussion of how to create a Wayland EGLDisplay
to follow the analogous discussion in the published
EGL_EXT_platform_x11 spec.
- Change resolution of issue 1 from yes to no, because of likely type
mismatch between EGL_DEFAULT_DISPLAY_TYPE and void*.
Version 1, 2013-04-26 (Chad Versace)
- Initial draft
# vim:ai:et:sw=4:ts=4:
