[PATCH weston v2 07/12] gl-renderer: Always setup gl-renderer

Pekka Paalanen ppaalanen at gmail.com
Mon Jun 27 13:08:43 UTC 2016


Hi Armin,

several minor nitpicks on wording here, but the code looks good.

On Thu, 23 Jun 2016 11:59:35 +0200
Armin Krezović <krezovic.armin at gmail.com> wrote:

> Currently, the gl-renderer setup is being done on per-output
> basis. This isn't desirable when trying to make weston run
> with zero outputs.

On "first output" rather than "per-output" basis.

> 
> When there are no outputs present, there is no surface available
> to attach an EGLContext to with eglMakeCurrent, which makes
> any EGL command fail.

GL command. Only certain EGL calls use the current context, while all
GL calls use it. Specifically, image_target_texture_2d is the GL
function glEGLImageTargetTexture2DOES which IIRC was failing without
the renderer setup.

> 
> The problem is solved by using EGL_KHR_surfaceless_context to
> bind an EGLContext to EGL_NO_SURFACE, or if that is
> unavailable, creating a dummy PbufferSurface and binding an
> EGLContext to it, so EGL gets set up properly.
> 
> v2:
> 
> - Move PbufferSurface creation into its own function
> - Introduce a new EGLConfig with EGL_PBUFFER_BIT set
>   and use it to create a PbufferSurface
> - Make PbufferSurface attributes definition static
> - Check for return of gl_renderer_setup and terminate
>   in case it fails
> - Remove redundant gl_renderer_setup call from
>   gl_renderer_output_create
> - Only destroy the dummy surface if it is valid
> 
> Signed-off-by: Armin Krezović <krezovic.armin at gmail.com>
> ---
>  src/gl-renderer.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 65 insertions(+), 6 deletions(-)
> 
> diff --git a/src/gl-renderer.c b/src/gl-renderer.c
> index 23c0cd7..28c0b50 100644
> --- a/src/gl-renderer.c
> +++ b/src/gl-renderer.c
> @@ -175,6 +175,8 @@ struct gl_renderer {
>  	EGLContext egl_context;
>  	EGLConfig egl_config;
>  
> +	EGLSurface dummy_surface;
> +
>  	struct wl_array vertices;
>  	struct wl_array vtxcnt;
>  
> @@ -201,6 +203,8 @@ struct gl_renderer {
>  
>  	int has_configless_context;
>  
> +	int has_surfaceless_context;
> +
>  	int has_dmabuf_import;
>  	struct wl_list dmabuf_images;
>  
> @@ -2597,12 +2601,6 @@ gl_renderer_output_create(struct weston_output *output,
>  		return -1;
>  	}
>  
> -	if (gr->egl_context == NULL)
> -		if (gl_renderer_setup(ec, go->egl_surface) < 0) {
> -			free(go);
> -			return -1;
> -		}
> -
>  	for (i = 0; i < BUFFER_DAMAGE_COUNT; i++)
>  		pixman_region32_init(&go->buffer_damage[i]);
>  
> @@ -2654,6 +2652,9 @@ gl_renderer_destroy(struct weston_compositor *ec)
>  	wl_list_for_each_safe(image, next, &gr->dmabuf_images, link)
>  		dmabuf_image_destroy(image);
>  
> +	if (gr->dummy_surface != EGL_NO_SURFACE)
> +		eglDestroySurface(gr->egl_display, gr->dummy_surface);
> +
>  	eglTerminate(gr->egl_display);
>  	eglReleaseThread();
>  
> @@ -2765,6 +2766,9 @@ gl_renderer_setup_egl_extensions(struct weston_compositor *ec)
>  		gr->has_configless_context = 1;
>  #endif
>  
> +	if (check_extension(extensions, "EGL_KHR_surfaceless_context"))
> +		gr->has_surfaceless_context = 1;
> +
>  #ifdef EGL_EXT_image_dma_buf_import
>  	if (check_extension(extensions, "EGL_EXT_image_dma_buf_import"))
>  		gr->has_dmabuf_import = 1;
> @@ -2795,6 +2799,7 @@ static const EGLint gl_renderer_alpha_attribs[] = {
>  	EGL_NONE
>  };
>  
> +
>  /** Checks whether a platform EGL client extension is supported
>   *
>   * \param ec The weston compositor
> @@ -2873,6 +2878,43 @@ platform_to_extension(EGLenum platform)
>  }
>  
>  static int
> +gl_renderer_create_pbuffer_surface(struct gl_renderer *gr) {

Style-wise, this function could just take a EGLDisplay as an argument,
and return the EGLSurface. That way the setting of dummy_surface would
be in the caller, which would make it easier to read.

> +	EGLConfig pbuffer_config;
> +
> +	static const EGLint pbuffer_config_attribs[] = {
> +		EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
> +		EGL_RED_SIZE, 1,
> +		EGL_GREEN_SIZE, 1,
> +		EGL_BLUE_SIZE, 1,
> +		EGL_ALPHA_SIZE, 0,
> +		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
> +		EGL_NONE
> +	};
> +
> +	static const EGLint pbuffer_attribs[] = {
> +		EGL_WIDTH, 10,
> +		EGL_HEIGHT, 10,
> +		EGL_NONE
> +	};
> +
> +	if (egl_choose_config(gr, pbuffer_config_attribs, NULL, 0, &pbuffer_config) < 0) {
> +		weston_log("failed to choose EGL config for PbufferSurface");
> +		return -1;
> +	}
> +
> +	gr->dummy_surface = eglCreatePbufferSurface(gr->egl_display,
> +						    pbuffer_config,
> +						    pbuffer_attribs);
> +
> +	if (gr->dummy_surface == EGL_NO_SURFACE) {
> +		weston_log("failed to create PbufferSurface\n");
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
>  gl_renderer_create(struct weston_compositor *ec, EGLenum platform,
>  	void *native_window, const EGLint *attribs,
>  	const EGLint *visual_id, int n_ids)
> @@ -2956,10 +2998,27 @@ gl_renderer_create(struct weston_compositor *ec, EGLenum platform,
>  	if (gr->has_dmabuf_import)
>  		gr->base.import_dmabuf = gl_renderer_import_dmabuf;
>  
> +	if (gr->has_surfaceless_context) {
> +		weston_log("EGL_KHR_surfaceless_context available\n");
> +		gr->dummy_surface = EGL_NO_SURFACE;
> +	} else {
> +		weston_log("EGL_KHR_surfaceless_context unavailable. "
> +			   "Trying PbufferSurface\n");
> +
> +		if (gl_renderer_create_pbuffer_surface(gr) < 0)
> +			goto fail_with_error;
> +	}
> +
>  	wl_display_add_shm_format(ec->wl_display, WL_SHM_FORMAT_RGB565);
>  
>  	wl_signal_init(&gr->destroy_signal);
>  
> +	if (gl_renderer_setup(ec, gr->dummy_surface) < 0) {
> +		if (gr->dummy_surface != EGL_NO_SURFACE)
> +			eglDestroySurface(gr->egl_display, gr->dummy_surface);

To follow the error clean-up style, you'd have a new goto label
'fail_with_dummy' or something, put the eglDestroySurface() call after
that, and then let it fall through to fail_with_error etc.

But, not a big deal.

> +		goto fail_with_error;
> +	}
> +
>  	return 0;
>  
>  fail_with_error:

I filed a Mesa bug about the "libEGL warning: FIXME: egl/x11 doesn't
support front buffer rendering." because I think it's wrong:
https://bugs.freedesktop.org/show_bug.cgi?id=96694

I don't think it should hurt anything though, so pushed:
   ea0316a..28d240f  master -> master

The rest of the series is for another day.


Thanks,
pq
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