[Mesa-dev] [PATCH 2/3] mesa/st: use ESSL cap top enable gpu_shader5 (v2)

[Ilia Mirkin]

On Thu, Mar 21, 2019 at 1:45 PM Rob Clark <robdclark at gmail.com> wrote:
>
> For GLES2+ contexts, enable EXT_gpu_shader5 if the driver exposes a
> sufficiently high ESSL feature level, even if the GLSL feature level
> isn't high enough.
>
> This allows drivers to support EXT_gpu_shader5 in GLES contexts before
> they support all the additional features of ARB_gpu_shader5 in GL
> contexts.
>
> We can also use this cap to enable ARB_ES3_1_compatibility.

I believe this is no longer the case, so probably remove that line.
Also, all the cool people talk about the OES_* variants of the exts...
Doesn't really matter, of course. They're identical.

>
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---
> This kinda morphed into also fixing OES_viewport_array (which should
> depend on GLES 3.2)
>
>  src/mesa/state_tracker/st_extensions.c | 24 +++++++++++++++++-------
>  1 file changed, 17 insertions(+), 7 deletions(-)
>
> diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
> index c953bfd9f7a..7c3b98c1ba6 100644
> --- a/src/mesa/state_tracker/st_extensions.c
> +++ b/src/mesa/state_tracker/st_extensions.c
> @@ -1056,6 +1056,8 @@ void st_init_extensions(struct pipe_screen *screen,
>     consts->GLSLVersionCompat =
>        screen->get_param(screen, PIPE_CAP_GLSL_FEATURE_LEVEL_COMPATIBILITY);
>
> +   const unsigned ESSLVersion =
> +      screen->get_param(screen, PIPE_CAP_ESSL_FEATURE_LEVEL);
>     const unsigned GLSLVersion =
>        api == API_OPENGL_COMPAT ? consts->GLSLVersionCompat :
>                                   consts->GLSLVersion;
> @@ -1077,6 +1079,13 @@ void st_init_extensions(struct pipe_screen *screen,
>
>     consts->AllowGLSLCrossStageInterpolationMismatch = options->allow_glsl_cross_stage_interpolation_mismatch;
>
> +   /* Technically we are turning on the EXT_gpu_shader5 extension,
> +    * ARB_gpu_shader5 does not exist in GLES, but this flag is what
> +    * switches on EXT_gpu_shader5:
> +    */
> +   if (api == API_OPENGLES2 && ESSLVersion >= 320)
> +      extensions->ARB_gpu_shader5 = GL_TRUE;
> +
>     if (GLSLVersion >= 400)
>        extensions->ARB_gpu_shader5 = GL_TRUE;
>     if (GLSLVersion >= 410)
> @@ -1540,16 +1549,12 @@ void st_init_extensions(struct pipe_screen *screen,
>        extensions->EXT_shader_integer_mix;
>
>     extensions->OES_texture_cube_map_array =
> -      extensions->ARB_ES3_1_compatibility &&
> +      (extensions->ARB_ES3_1_compatibility || ESSLVersion >= 310) &&

It's a bit more work, but if you get all the drivers to properly
expose this cap, you could make this *just* ESSLVersion >= x, instead
of also relying on the ARB_* thing. Totally your call, just wanted to
make the observation.

>        extensions->OES_geometry_shader &&
>        extensions->ARB_texture_cube_map_array;
>
> -   extensions->OES_viewport_array =
> -      extensions->ARB_ES3_1_compatibility &&
> -      extensions->OES_geometry_shader &&
> -      extensions->ARB_viewport_array;
> -
> -   extensions->OES_primitive_bounding_box = extensions->ARB_ES3_1_compatibility;
> +   extensions->OES_primitive_bounding_box =
> +      extensions->ARB_ES3_1_compatibility || (ESSLVersion >= 310);
>     consts->NoPrimitiveBoundingBoxOutput = true;
>
>     extensions->ANDROID_extension_pack_es31a =
> @@ -1590,6 +1595,11 @@ void st_init_extensions(struct pipe_screen *screen,
>        extensions->ARB_texture_stencil8 &&
>        extensions->ARB_texture_multisample;
>
> +   extensions->OES_viewport_array =
> +      (extensions->ARB_ES3_2_compatibility || ESSLVersion >= 320) &&

Why is this getting bumped up to needing ES 3.2? Did you mean to leave
this at ES3_1_compat || ESSL >= 310?

"OpenGL ES 3.2, EXT_geometry_shader or OES_geometry_shader is
required." (Note the "or". Otherwise it'd make no sense since ES 3.2
includes geometry shaders as core functionality.)


> +      extensions->OES_geometry_shader &&
> +      extensions->ARB_viewport_array;
> +
>     if (screen->get_param(screen, PIPE_CAP_CONSERVATIVE_RASTER_POST_SNAP_TRIANGLES) &&
>         screen->get_param(screen, PIPE_CAP_CONSERVATIVE_RASTER_POST_SNAP_POINTS_LINES) &&
>         screen->get_param(screen, PIPE_CAP_CONSERVATIVE_RASTER_POST_DEPTH_COVERAGE)) {
> --
> 2.20.1
>