[Mesa-dev] [PATCH 10/34] glsl: add builtins for geometry shaders.

[Kenneth Graunke]

On 07/28/2013 11:03 PM, Paul Berry wrote:
> From: Bryan Cain <bryancain3 at gmail.com>
>
> v2 (Paul Berry <stereotype441 at gmail.com>): Account for rework of
> builtin_variables.cpp.  Use INTERP_QUALIFIER_FLAT for gl_PrimitiveID
> so that it will obey provoking vertex conventions.  Convert to GLSL
> 1.50 style geometry shaders.
> ---
>   src/glsl/builtin_variables.cpp               | 11 +++++++++--
>   src/glsl/builtins/ir/EmitVertex.ir           |  5 +++++
>   src/glsl/builtins/ir/EndPrimitive.ir         |  5 +++++
>   src/glsl/builtins/profiles/150.geom          |  3 +++
>   src/glsl/builtins/tools/generate_builtins.py |  6 ++++--
>   5 files changed, 26 insertions(+), 4 deletions(-)
>   create mode 100644 src/glsl/builtins/ir/EmitVertex.ir
>   create mode 100644 src/glsl/builtins/ir/EndPrimitive.ir
>   create mode 100644 src/glsl/builtins/profiles/150.geom
>
> diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
> index 1e88b6a..9d927a4 100644
> --- a/src/glsl/builtin_variables.cpp
> +++ b/src/glsl/builtin_variables.cpp
> @@ -686,8 +686,10 @@ builtin_variable_generator::generate_gs_special_vars()
>       * the specific case of gl_PrimitiveIDIn.  So we don't need to treat
>       * gl_PrimitiveIDIn as an {ARB,EXT}_geometry_shader4-only variable.
>       */
> -   add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveIDIn");
> -   add_output(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
> +   add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveIDIn")
> +      ->interpolation = INTERP_QUALIFIER_FLAT;
> +   add_output(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID")
> +      ->interpolation = INTERP_QUALIFIER_FLAT;
>   }

This took a moment to understand :)

Could we instead use a temporary?  Something like:

    ir_variable *var;
    var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveIDIn");
    var->interpolation = INTERP_QUALIFIER_FLAT;
    var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
    var->interpolation = INTERP_QUALIFIER_FLAT;

etc.

>
>
> @@ -702,6 +704,11 @@ builtin_variable_generator::generate_fs_special_vars()
>      if (state->is_version(120, 100))
>         add_input(VARYING_SLOT_PNTC, vec2_t, "gl_PointCoord");
>
> +   if (state->is_version(150, 0)) {
> +      add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID")
> +         ->interpolation = INTERP_QUALIFIER_FLAT;

Ditto.

> +   }
> +
>      /* gl_FragColor and gl_FragData were deprecated starting in desktop GLSL
>       * 1.30, and were relegated to the compatibility profile in GLSL 4.20.
>       * They were removed from GLSL ES 3.00.
> diff --git a/src/glsl/builtins/ir/EmitVertex.ir b/src/glsl/builtins/ir/EmitVertex.ir
> new file mode 100644
> index 0000000..e08ec62
> --- /dev/null
> +++ b/src/glsl/builtins/ir/EmitVertex.ir
> @@ -0,0 +1,5 @@
> +((function EmitVertex
> +  (signature void
> +    (parameters)
> +    ((emitvertex)))
> +))
> diff --git a/src/glsl/builtins/ir/EndPrimitive.ir b/src/glsl/builtins/ir/EndPrimitive.ir
> new file mode 100644
> index 0000000..ea6ecfd
> --- /dev/null
> +++ b/src/glsl/builtins/ir/EndPrimitive.ir
> @@ -0,0 +1,5 @@
> +((function EndPrimitive
> +  (signature void
> +    (parameters)
> +    ((endprim)))
> +))
> diff --git a/src/glsl/builtins/profiles/150.geom b/src/glsl/builtins/profiles/150.geom
> new file mode 100644
> index 0000000..d2ab891
> --- /dev/null
> +++ b/src/glsl/builtins/profiles/150.geom
> @@ -0,0 +1,3 @@
> +#version 150
> +void EmitVertex();
> +void EndPrimitive();
> diff --git a/src/glsl/builtins/tools/generate_builtins.py b/src/glsl/builtins/tools/generate_builtins.py
> index 85bd5dd..54c5a49 100755
> --- a/src/glsl/builtins/tools/generate_builtins.py
> +++ b/src/glsl/builtins/tools/generate_builtins.py
> @@ -125,7 +125,7 @@ def write_profiles():
>
>   def get_profile_list():
>       profile_files = []
> -    for extension in ['glsl', 'frag', 'vert']:
> +    for extension in ['glsl', 'frag', 'vert', 'geom']:
>           path_glob = path.join(
>               path.join(builtins_dir, 'profiles'), '*.' + extension)
>           profile_files.extend(glob(path_glob))
> @@ -279,10 +279,12 @@ _mesa_glsl_initialize_functions(struct _mesa_glsl_parse_state *state)
>               check = 'state->target == vertex_shader && '
>           elif profile.endswith('_frag'):
>               check = 'state->target == fragment_shader && '
> +        elif profile.endswith('_geom'):
> +            check = 'state->target == geometry_shader && '
>           else:
>               check = ''
>
> -        version = re.sub(r'_(glsl|vert|frag)$', '', profile)
> +        version = re.sub(r'_(glsl|vert|frag|geom)$', '', profile)
>           if version[0].isdigit():
>               is_es = version.endswith('es')
>               if is_es:
>