From 27f4e381736f0abee35aa25035cb54b5c34f9bef Mon Sep 17 00:00:00 2001 From: Chad Versace Date: Thu, 22 Sep 2016 21:36:17 -0700 Subject: docs: Add EGL_MESA_platform_surfaceless.txt (v2) v2: - Assign enum values. - Define interactions with EGL_EXT_platform_base and EGL 1.4. Reviewed-by: Emil Velikov --- docs/specs/EGL_MESA_platform_surfaceless.txt | 120 +++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 docs/specs/EGL_MESA_platform_surfaceless.txt (limited to 'docs') diff --git a/docs/specs/EGL_MESA_platform_surfaceless.txt b/docs/specs/EGL_MESA_platform_surfaceless.txt new file mode 100644 index 0000000..871ee50 --- /dev/null +++ b/docs/specs/EGL_MESA_platform_surfaceless.txt @@ -0,0 +1,120 @@ +Name + + MESA_platform_surfaceless + +Name Strings + + EGL_MESA_platform_surfaceless + +Contributors + + Chad Versace + Haixia Shi + Stéphane Marchesin + Zach Reizner + Gurchetan Singh + +Contacts + + Chad Versace + +Status + + DRAFT + +Version + + Version 2, 2016-10-13 + +Number + + EGL Extension #TODO + +Extension Type + + EGL client extension + +Dependencies + + Requires EGL 1.5 or later; or EGL 1.4 with EGL_EXT_platform_base. + + This extension is written against the EGL 1.5 Specification (draft + 20140122). + + This extension interacts with EGL_EXT_platform_base as follows. If the + implementation supports EGL_EXT_platform_base, then text regarding + eglGetPlatformDisplay applies also to eglGetPlatformDisplayEXT; + eglCreatePlatformWindowSurface to eglCreatePlatformWindowSurfaceEXT; and + eglCreatePlatformPixmapSurface to eglCreatePlatformPixmapSurfaceEXT. + +Overview + + This extension defines a new EGL platform, the "surfaceless" platform. This + platfom's defining property is that it has no native surfaces, and hence + neither eglCreatePlatformWindowSurface nor eglCreatePlatformPixmapSurface + can be used. The platform is independent of any native window system. + + The platform's intended use case is for enabling OpenGL and OpenGL ES + applications on systems where no window system exists. However, the + platform's permitted usage is not restricted to this case. Since the + platform is independent of any native window system, it may also be used on + systems where a window system is present. + +New Types + + None + +New Procedures and Functions + + None + +New Tokens + + Accepted as the argument of eglGetPlatformDisplay: + + EGL_PLATFORM_SURFACELESS_MESA 0x31DD + +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 on the surfaceless platform, call + eglGetPlatformDisplay with set to EGL_PLATFORM_SURFACELESS_MESA. + The parameter must be EGL_DEFAULT_DISPLAY. + + eglCreatePlatformWindowSurface fails when called with a that + belongs to the surfaceless platform. It returns EGL_NO_SURFACE and + generates EGL_BAD_NATIVE_WINDOW. The justification for this unconditional + failure is that the surfaceless platform has no native windows, and + therefore the parameter is always invalid. + + Likewise, eglCreatePlatformPixmapSurface also fails when called with a + that belongs to the surfaceless platform. It returns + EGL_NO_SURFACE and generates EGL_BAD_NATIVE_PIXMAP. + + The surfaceless platform imposes no platform-specific restrictions on the + creation of pbuffers, as eglCreatePbufferSurface has no native surface + parameter. Specifically, if the EGLDisplay advertises an EGLConfig whose + EGL_SURFACE_TYPE attribute contains EGL_PBUFFER_BIT, then the EGLDisplay + permits the creation of pbuffers with that config. + +Issues + + None. + +Revision History + + Version 2, 2016-10-13 (Chad Versace) + - Assign enum values + - Define interfactions with EGL 1.4 and EGL_EXT_platform_base. + - Add Gurchetan as contributor, as he implemented the pbuffer support. + + Version 1, 2016-09-23 (Chad Versace) + - Initial version + - Posted for review at + https://lists.freedesktop.org/archives/mesa-dev/2016-September/129549.html -- cgit v1.1