[Mesa-dev] [PATCH 2/3] glsl: add AMD_vertex_shader_layer support

[Ian Romanick]

On 04/27/2013 04:32 PM, Jordan Justen wrote:
> This GLSL extension requires that AMD_vertex_shader_layer be
> enabled by the driver.

Most (all?) extensions also add a preprocessor define.  Can you poke at 
AMD's driver to see if GL_AMD_vertex_shader_layer is defined?  If so, 
then we need to add it too.

> Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
> ---
>   src/glsl/builtin_variables.cpp  |   31 +++++++++++++++++++++++++++++++
>   src/glsl/glsl_parser_extras.cpp |    1 +
>   src/glsl/glsl_parser_extras.h   |    2 ++
>   3 files changed, 34 insertions(+)
>
> diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
> index b0c7a20..098c3f1 100644
> --- a/src/glsl/builtin_variables.cpp
> +++ b/src/glsl/builtin_variables.cpp
> @@ -39,6 +39,12 @@ generate_ARB_draw_instanced_variables(exec_list *,
>                                         struct _mesa_glsl_parse_state *,
>                                         bool, _mesa_glsl_parser_targets);
>
> +static void
> +generate_AMD_vertex_shader_layer_variables(exec_list *instructions,
> +                                           struct _mesa_glsl_parse_state *state,
> +                                           bool warn,
> +                                           _mesa_glsl_parser_targets target);
> +
>   struct builtin_variable {
>      enum ir_variable_mode mode;
>      int slot;
> @@ -818,6 +824,8 @@ generate_130_vs_variables(exec_list *instructions,
>   		"gl_ClipDistance", clip_distance_array_type, ir_var_shader_out,
>                   VARYING_SLOT_CLIP_DIST0);
>
> +   generate_AMD_vertex_shader_layer_variables(instructions, state, false,
> +                                              vertex_shader);
>   }
>
>
> @@ -1020,6 +1028,29 @@ generate_ARB_draw_instanced_variables(exec_list *instructions,
>      }
>   }
>
> +static void
> +generate_AMD_vertex_shader_layer_variables(exec_list *instructions,
> +                                           struct _mesa_glsl_parse_state *state,
> +                                           bool warn,
> +                                           _mesa_glsl_parser_targets target)
> +{
> +   /* gl_Layer is only available in the vertex shader for the
> +    * AMD_vertex_shader_layer extension. It will also be available in the
> +    * geometry shader when GLSL 1.50 is supported.
> +    */
> +   if (target != vertex_shader)
> +      return;
> +
> +   if (state->AMD_vertex_shader_layer_enable) {
> +      ir_variable *inst =
> +         add_variable(instructions, state->symbols,
> +                      "gl_Layer", glsl_type::int_type,
> +                      ir_var_shader_out, VARYING_SLOT_LAYER);
> +
> +      if (warn)
> +         inst->warn_extension = "GL_AMD_vertex_shader_layer";
> +   }
> +}
>
>   static void
>   generate_ARB_shader_stencil_export_variables(exec_list *instructions,
> diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
> index 0992294..e419264 100644
> --- a/src/glsl/glsl_parser_extras.cpp
> +++ b/src/glsl/glsl_parser_extras.cpp
> @@ -468,6 +468,7 @@ static const _mesa_glsl_extension _mesa_glsl_supported_extensions[] = {
>      EXT(ARB_shading_language_packing,   true,  false, true,  true,  false,     ARB_shading_language_packing),
>      EXT(ARB_texture_multisample,        true,  false, true,  true,  false,     ARB_texture_multisample),
>      EXT(ARB_texture_query_lod,          false, false, true,  true,  false,     ARB_texture_query_lod),
> +   EXT(AMD_vertex_shader_layer,        true,  false, false, true,  false,     AMD_vertex_shader_layer),
>   };
>
>   #undef EXT
> diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
> index 95891b5..3386365 100644
> --- a/src/glsl/glsl_parser_extras.h
> +++ b/src/glsl/glsl_parser_extras.h
> @@ -284,6 +284,8 @@ struct _mesa_glsl_parse_state {
>      bool ARB_texture_multisample_warn;
>      bool ARB_texture_query_lod_enable;
>      bool ARB_texture_query_lod_warn;
> +   bool AMD_vertex_shader_layer_enable;
> +   bool AMD_vertex_shader_layer_warn;
>      /*@}*/
>
>      /** Extensions supported by the OpenGL implementation. */
>