[Mesa-dev] [PATCH 2/2] mesa: enable ARB_gpu_shader5 in compat

Timothy Arceri tarceri at itsqueeze.com
Fri May 18 09:25:16 UTC 2018


Hi Benedikt,

I think you have this backwards. compute_version() computes the version 
of OpenGL supported by the driver by checking what extensions it 
advertises. See version 2 of my patch to see where the extensions are 
enabled. I don't think this is something that can be automated, it 
really depends on the driver, just because an extension can be 
advertised at a certain level doesn't mean you must (or can) do it.

Tim

On 18/05/18 19:13, Benedikt Schemmer wrote:
> Hi Timothy,
> 
> I was looking into something similar myself.
> Great to see someone working on getting legacy extensions available
> to the applications that can actually use them!
> 
> Another thing I noticed is that extensions aren't advertised at the
> correct feature level.
> The code below works and does a better job at it, but its probably also
> the wrong way to go about it.
> 
> Cheers,
> Benedikt
> 
> P.S. I grepped and sed together a file which describes the requirements
> for every extension better, unfortunately the files on khronos
> arent exactly machine readable
> will send in next reply
> 
> ---
> 
> diff --git a/src/mesa/main/version.c b/src/mesa/main/version.c
> --- a/src/mesa/main/version.c
> +++ b/src/mesa/main/version.c
> @@ -233,8 +233,15 @@ _mesa_override_glsl_version(struct gl_constants *consts)
>   }
> 
>   /**
> - * Examine enabled GL extensions to determine GL version.
> + * Enable GL Extensions according to the minimum version requirements as per spec.
> + * Careful: some extensions are implemented for the express purpose of being
> + * used in a lower version context (legacy extensions).
> + * Example:
> + * ARB_gpu_shader5: first implementation in OpenGL 4.0 (GLSL 400) but
> + * supposed to be advertised from OpenGL 3.2 (GLSL 150) upwards,
> + * however early Nvidia FXAA could use it from GLSL 120 so advertise it there
>    */
> +
>   static GLuint
>   compute_version(const struct gl_extensions *extensions,
>                   const struct gl_constants *consts, gl_api api)
> @@ -242,25 +249,43 @@ compute_version(const struct gl_extensions *extensions,
>      GLuint major, minor, version;
> 
>      const bool ver_1_3 = (extensions->ARB_texture_border_clamp &&
> +                         extensions->ARB_instanced_arrays &&
> +                         extensions->ARB_shadow &&
> +                         extensions->ARB_vertex_shader &&
> +                         extensions->ARB_fragment_shader &&
> +                         extensions->ARB_depth_texture &&
> +                         extensions->ARB_occlusion_query2 &&
>                            extensions->ARB_texture_cube_map &&
> +                         extensions->ARB_seamless_cube_map &&
>                            extensions->ARB_texture_env_combine &&
> +                         extensions->ARB_texture_rg &&
> +                         extensions->ARB_texture_compression_rgtc &&
> +                         extensions->ARB_texture_compression_bptc &&
> +                         extensions->ARB_texture_float &&
> +                         extensions->ARB_framebuffer_object &&
> +                         extensions->ARB_framebuffer_no_attachments &&
>                            extensions->ARB_texture_env_dot3);
>      const bool ver_1_4 = (ver_1_3 &&
> -                         extensions->ARB_depth_texture &&
> -                         extensions->ARB_shadow &&
> +                         extensions->ARB_stencil_texturing &&
>                            extensions->ARB_texture_env_crossbar &&
> +                         extensions->ARB_texture_mirror_clamp_to_edge &&
>                            extensions->EXT_blend_color &&
>                            extensions->EXT_blend_func_separate &&
>                            extensions->EXT_blend_minmax &&
>                            extensions->EXT_point_parameters);
>      const bool ver_1_5 = (ver_1_4 &&
> +                         extensions->ARB_query_buffer_object &&
>                            extensions->ARB_occlusion_query);
>      const bool ver_2_0 = (ver_1_5 &&
>                            extensions->ARB_point_sprite &&
> -                         extensions->ARB_vertex_shader &&
> -                         extensions->ARB_fragment_shader &&
> +                         extensions->ARB_blend_func_extended &&
>                            extensions->ARB_texture_non_power_of_two &&
>                            extensions->EXT_blend_equation_separate &&
> +                         extensions->ARB_shader_texture_lod &&
> +                         extensions->ARB_transform_feedback2 &&
> +                         extensions->ARB_uniform_buffer_object &&
> +                         extensions->ARB_texture_buffer_object &&
> +                         extensions->ARB_texture_buffer_range &&
> 
>                            /* Technically, 2.0 requires the functionality of the
>                             * EXT version.  Enable 2.0 if either extension is
> @@ -272,33 +297,44 @@ compute_version(const struct gl_extensions *extensions,
>                             || extensions->ATI_separate_stencil));
>      const bool ver_2_1 = (ver_2_0 &&
>                            extensions->EXT_pixel_buffer_object &&
> +                         extensions->ARB_map_buffer_range &&
> +                         extensions->ARB_draw_instanced &&
> +                         extensions->ARB_shader_bit_encoding &&
> +                         extensions->ARB_gpu_shader5 &&
>                            extensions->EXT_texture_sRGB);
>      const bool ver_3_0 = (ver_2_1 &&
>                            consts->GLSLVersion >= 130 &&
>                            (consts->MaxSamples >= 4 || consts->FakeSWMSAA) &&
>                            (api == API_OPENGL_CORE ||
>                             extensions->ARB_color_buffer_float) &&
> +                         extensions->ARB_conservative_depth &&
>                            extensions->ARB_depth_buffer_float &&
>                            extensions->ARB_half_float_vertex &&
> -                         extensions->ARB_map_buffer_range &&
> -                         extensions->ARB_shader_texture_lod &&
> -                         extensions->ARB_texture_float &&
> -                         extensions->ARB_texture_rg &&
> -                         extensions->ARB_texture_compression_rgtc &&
> +                         extensions->ARB_pipeline_statistics_query &&
> +                         extensions->ARB_shader_image_load_store &&
> +                         extensions->ARB_texture_rgb10_a2ui &&
> +                         extensions->ARB_vertex_type_10f_11f_11f_rev &&
>                            extensions->EXT_draw_buffers2 &&
> -                         extensions->ARB_framebuffer_object &&
> +                         extensions->ARB_transform_feedback_instanced &&
> +                         extensions->ARB_internalformat_query &&
> +                         extensions->ARB_internalformat_query2 &&
>                            extensions->EXT_framebuffer_sRGB &&
>                            extensions->EXT_packed_float &&
> +                         extensions->ARB_sample_shading &&
> +                         extensions->ARB_shader_atomic_counters &&
>                            extensions->EXT_texture_array &&
> +                         extensions->ARB_texture_query_lod &&
>                            extensions->EXT_texture_shared_exponent &&
>                            extensions->EXT_transform_feedback &&
> -                         extensions->NV_conditional_render);
> +                         extensions->NV_conditional_render &&
> +                         extensions->ARB_texture_cube_map_array &&
> +                         extensions->ARB_transform_feedback_overflow_query);
>      const bool ver_3_1 = (ver_3_0 &&
>                            consts->GLSLVersion >= 140 &&
> -                         extensions->ARB_draw_instanced &&
> -                         extensions->ARB_texture_buffer_object &&
> -                         extensions->ARB_uniform_buffer_object &&
>                            extensions->EXT_texture_snorm &&
> +                         extensions->ARB_shading_language_420pack &&
> +                         extensions->ARB_sync &&
> +                         extensions->ARB_draw_indirect &&
>                            extensions->NV_primitive_restart &&
>                            extensions->NV_texture_rectangle &&
>                            consts->Program[MESA_SHADER_VERTEX].MaxTextureImageUnits >= 16);
> @@ -308,18 +344,17 @@ compute_version(const struct gl_extensions *extensions,
>                            extensions->ARB_draw_elements_base_vertex &&
>                            extensions->ARB_fragment_coord_conventions &&
>                            extensions->EXT_provoking_vertex &&
> -                         extensions->ARB_seamless_cube_map &&
> -                         extensions->ARB_sync &&
> +                         extensions->ARB_gpu_shader_fp64 &&
> +                         extensions->ARB_vertex_attrib_64bit &&
>                            extensions->ARB_texture_multisample &&
> -                         extensions->EXT_vertex_array_bgra);
> +                         extensions->ARB_tessellation_shader &&
> +                         extensions->EXT_vertex_array_bgra &&
> +                         extensions->ARB_fragment_layer_viewport &&
> +                         extensions->ARB_viewport_array);
>      const bool ver_3_3 = (ver_3_2 &&
>                            consts->GLSLVersion >= 330 &&
> -                         extensions->ARB_blend_func_extended &&
>                            extensions->ARB_explicit_attrib_location &&
> -                         extensions->ARB_instanced_arrays &&
> -                         extensions->ARB_occlusion_query2 &&
> -                         extensions->ARB_shader_bit_encoding &&
> -                         extensions->ARB_texture_rgb10_a2ui &&
> +                         extensions->ARB_explicit_uniform_location &&
>                            extensions->ARB_timer_query &&
>                            extensions->ARB_vertex_type_2_10_10_10_rev &&
>                            extensions->EXT_texture_swizzle);
> @@ -328,67 +363,42 @@ compute_version(const struct gl_extensions *extensions,
>      const bool ver_4_0 = (ver_3_3 &&
>                            consts->GLSLVersion >= 400 &&
>                            extensions->ARB_draw_buffers_blend &&
> -                         extensions->ARB_draw_indirect &&
> -                         extensions->ARB_gpu_shader5 &&
> -                         extensions->ARB_gpu_shader_fp64 &&
> -                         extensions->ARB_sample_shading &&
> -                         extensions->ARB_tessellation_shader &&
> +                         extensions->ARB_derivative_control &&
>                            extensions->ARB_texture_buffer_object_rgb32 &&
> -                         extensions->ARB_texture_cube_map_array &&
> -                         extensions->ARB_texture_query_lod &&
> -                         extensions->ARB_transform_feedback2 &&
>                            extensions->ARB_transform_feedback3);
>      const bool ver_4_1 = (ver_4_0 &&
>                            consts->GLSLVersion >= 410 &&
>                            extensions->ARB_ES2_compatibility &&
> -                         extensions->ARB_shader_precision &&
> -                         extensions->ARB_vertex_attrib_64bit &&
> -                         extensions->ARB_viewport_array);
> +                         extensions->ARB_shading_language_packing &&
> +                         extensions->ARB_shader_precision);
>      const bool ver_4_2 = (ver_4_1 &&
>                            consts->GLSLVersion >= 420 &&
>                            extensions->ARB_base_instance &&
> -                         extensions->ARB_conservative_depth &&
> -                         extensions->ARB_internalformat_query &&
> -                         extensions->ARB_shader_atomic_counters &&
> -                         extensions->ARB_shader_image_load_store &&
> -                         extensions->ARB_shading_language_420pack &&
> -                         extensions->ARB_shading_language_packing &&
> -                         extensions->ARB_texture_compression_bptc &&
> -                         extensions->ARB_transform_feedback_instanced);
> +                         extensions->ARB_compute_shader &&
> +                         extensions->ARB_shader_atomic_counter_ops);
>      const bool ver_4_3 = (ver_4_2 &&
>                            consts->GLSLVersion >= 430 &&
>                            consts->Program[MESA_SHADER_VERTEX].MaxUniformBlocks >= 14 &&
>                            extensions->ARB_ES3_compatibility &&
>                            extensions->ARB_arrays_of_arrays &&
> -                         extensions->ARB_compute_shader &&
> +                         extensions->ARB_buffer_storage &&
>                            extensions->ARB_copy_image &&
> -                         extensions->ARB_explicit_uniform_location &&
> -                         extensions->ARB_fragment_layer_viewport &&
> -                         extensions->ARB_framebuffer_no_attachments &&
> -                         extensions->ARB_internalformat_query2 &&
>                            extensions->ARB_robust_buffer_access_behavior &&
>                            extensions->ARB_shader_image_size &&
>                            extensions->ARB_shader_storage_buffer_object &&
> -                         extensions->ARB_stencil_texturing &&
> -                         extensions->ARB_texture_buffer_range &&
>                            extensions->ARB_texture_query_levels &&
>                            extensions->ARB_texture_view);
>      const bool ver_4_4 = (ver_4_3 &&
>                            consts->GLSLVersion >= 440 &&
> -                         extensions->ARB_buffer_storage &&
>                            extensions->ARB_clear_texture &&
>                            extensions->ARB_enhanced_layouts &&
> -                         extensions->ARB_query_buffer_object &&
> -                         extensions->ARB_texture_mirror_clamp_to_edge &&
> -                         extensions->ARB_texture_stencil8 &&
> -                         extensions->ARB_vertex_type_10f_11f_11f_rev);
> +                         extensions->ARB_texture_stencil8);
>      const bool ver_4_5 = (ver_4_4 &&
>                            consts->GLSLVersion >= 450 &&
>                            extensions->ARB_ES3_1_compatibility &&
>                            extensions->ARB_clip_control &&
>                            extensions->ARB_conditional_render_inverted &&
>                            extensions->ARB_cull_distance &&
> -                         extensions->ARB_derivative_control &&
>                            extensions->ARB_shader_texture_image_samples &&
>                            extensions->NV_texture_barrier);
>      const bool ver_4_6 = (ver_4_5 &&
> @@ -396,13 +406,10 @@ compute_version(const struct gl_extensions *extensions,
>                            /* extensions->ARB_gl_spirv */ 0 &&
>                            /* extensions->ARB_spirv_extensions */ 0 &&
>                            extensions->ARB_indirect_parameters &&
> -                         extensions->ARB_pipeline_statistics_query &&
>                            extensions->ARB_polygon_offset_clamp &&
> -                         extensions->ARB_shader_atomic_counter_ops &&
>                            extensions->ARB_shader_draw_parameters &&
>                            extensions->ARB_shader_group_vote &&
> -                         extensions->ARB_texture_filter_anisotropic &&
> -                         extensions->ARB_transform_feedback_overflow_query);
> +                         extensions->ARB_texture_filter_anisotropic);
> 
>      if (ver_4_6) {
>         major = 4;
> 


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