[PATCH weston] gl-renderer: Use EGL_KHR_no_config_context

[Emil Velikov]

On 28 September 2016 at 20:54, Armin Krezović <krezovic.armin at gmail.com> wrote:
> On 27.09.2016 15:18, Emmanuel Gil Peyrot wrote:
>> On Tue, Sep 27, 2016 at 12:29:51PM +0200, Armin Krezović wrote:
>>> This patch makes use of recently implemented
>>> EGL_KHR_no_config_context extension in Mesa,
>>> which superseeds EGL_MESA_configless_context.
>>>
>>> See also (and the follow-up patch):
>>>
>>> https://lists.freedesktop.org/archives/mesa-dev/2016-September/128510.html
>>>
>>> Signed-off-by: Armin Krezović <krezovic.armin at gmail.com>
>>> ---
>>>  libweston/gl-renderer.c    | 14 +++++++++++---
>>>  libweston/weston-egl-ext.h |  3 +++
>>>  2 files changed, 14 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/libweston/gl-renderer.c b/libweston/gl-renderer.c
>>> index 031576b..7ef7b89 100644
>>> --- a/libweston/gl-renderer.c
>>> +++ b/libweston/gl-renderer.c
>>> @@ -199,6 +199,8 @@ struct gl_renderer {
>>>
>>>      int has_egl_buffer_age;
>>>
>>> +    int has_no_config_context;
>>> +
>>>      int has_configless_context;
>>
>> You don’t need to keep two different booleans for that, both extensions
>> are implemented and exposed the same way, only the wording changes a
>> bit.
>>
>>>
>>>      int has_surfaceless_context;
>>> @@ -2564,10 +2566,11 @@ gl_renderer_output_create(struct weston_output *output,
>>>      }
>>>
>>>      if (egl_config != gr->egl_config &&
>>> +        !gr->has_no_config_context &&
>>>          !gr->has_configless_context) {
>>>              weston_log("attempted to use a different EGL config for an "
>>> -                       "output but EGL_MESA_configless_context is not "
>>> -                       "supported\n");
>>> +                       "output but EGL_KHR_no_config_context or "
>>> +                       "EGL_MESA_configless_context is not supported\n");
>>>              return -1;
>>>      }
>>>
>>> @@ -2726,6 +2729,9 @@ gl_renderer_setup_egl_extensions(struct weston_compositor *ec)
>>>              weston_log("warning: EGL_EXT_swap_buffers_with_damage not "
>>>                         "supported. Performance could be affected.\n");
>>>
>>> +    if (weston_check_egl_extension(extensions, "EGL_KHR_no_config_context"))
>>> +            gr->has_no_config_context = 1;
>>> +
>>>      if (weston_check_egl_extension(extensions, "EGL_MESA_configless_context"))
>>>              gr->has_configless_context = 1;
>>
>> Same here, you can safely set gr->has_no_config_context instead.
>>
>>>
>>> @@ -3101,7 +3107,9 @@ gl_renderer_setup(struct weston_compositor *ec, EGLSurface egl_surface)
>>>
>>>      context_config = gr->egl_config;
>>>
>>> -    if (gr->has_configless_context)
>>> +    if (gr->has_no_config_context)
>>> +            context_config = EGL_NO_CONFIG_KHR;
>>> +    else if (gr->has_configless_context)
>>>              context_config = EGL_NO_CONFIG_MESA;
>>
>> And same here, the EGL_NO_CONFIG_KHR and EGL_NO_CONFIG_MESA values are
>> the same, so as long as you have both in the header (you do), it will
>> not be an issue.
>>
>>>
>>>      gr->egl_context = eglCreateContext(gr->egl_display, context_config,
>>> diff --git a/libweston/weston-egl-ext.h b/libweston/weston-egl-ext.h
>>> index 6e36996..50964a8 100644
>>> --- a/libweston/weston-egl-ext.h
>>> +++ b/libweston/weston-egl-ext.h
>>> @@ -152,5 +152,8 @@ typedef EGLSurface (EGLAPIENTRYP PFNEGLCREATEPLATFORMPIXMAPSURFACEEXTPROC) (EGLD
>>>  #define EGL_PLATFORM_X11_KHR 0x31D5
>>>  #endif
>>>
>>> +#ifndef EGL_NO_CONFIG_KHR
>>> +#define EGL_NO_CONFIG_KHR ((EGLConfig)0)
>>> +#endif
>>>
>>>  #endif
>>> --
>>> 2.10.0
>>>
>>> _______________________________________________
>>> wayland-devel mailing list
>>> wayland-devel at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/wayland-devel
>>
>
> Hi Emmanuel,
>
> Thanks for the review. I was going to implement it that way, but I wanted to keep
> up the tradition.
>
> If nobody complains about the way you suggested, I'll implement it that way.
>
Fwiw, I believe Emmanuel's suggestion is spot on.

The only difference between the two extensions is that the mesa
extension lacks explicit text error handling corner case. Everything
else is identical afaict, thus there's little need for a special case
in weston/other EGL users.

Regards,
Emil