[Mesa-dev] [RFC 08/21] mesa/extensions: Replace extension::api_set with ::version

[Chad Versace]

On Mon 19 Oct 2015, Nanley Chery wrote:
> From: Nanley Chery <nanley.g.chery at intel.com>
> 
> The api_set field has no users outside of _mesa_extension_supported().
> Remove it and allow the version field to take its place.
> 
> The brunt of the transformation was performed with the following vim commands:
> s/\(GL [^,]\+\),\s*\d*,\s*\d*\(,\s*\d*\)\(,\s*\d*\)/\1, GLL, GLC\2\3/g
> s/\(GLL [^,]\+\)\,\s*\d*/\1, GLL/g
> s/\(GLC [^,]\+\)\(,\s*\d*\),\s*\d*\(,\s*\d*\)\(,\s*\d*\)/\1\2, GLC\3\4/g
> s/\( ES1[^,]*\)\(,\s*\(\w\|\d\)\+\)\(,\s*\(\w\|\d\)\+\),\s*\d*/\1\2\4, ES1/g
> s/\( ES2[^,]*\)\(,\s*\(\w\|\d\)\+\)\(,\s*\(\w\|\d\)\+\)\(,\s*\(\w\|\d\)\+\),\s*\d*/\1\2\4\6, ES2/g
> 
> Signed-off-by: Nanley Chery <nanley.g.chery at intel.com>
> ---
>  src/mesa/main/extensions.c       |  21 +-
>  src/mesa/main/extensions_table.h | 636 ++++++++++++++++++++-------------------
>  2 files changed, 326 insertions(+), 331 deletions(-)

[...]

> diff --git a/src/mesa/main/extensions_table.h b/src/mesa/main/extensions_table.h

[...]

> +#define GLL 0
> +#define GLC 0
> +#define ES1 0
> +#define ES2 0
> +#define  x ~0

> +EXT(EXT_abgr                                , dummy_true                             , GLL, GLC,  x ,  x , 1995)
> +EXT(EXT_bgra                                , dummy_true                             , GLL,  x ,  x ,  x , 1995)
> +EXT(EXT_blend_color                         , EXT_blend_color                        , GLL,  x ,  x ,  x , 1995)
> +EXT(EXT_blend_equation_separate             , EXT_blend_equation_separate            , GLL, GLC,  x ,  x , 2003)
> +EXT(EXT_blend_func_separate                 , EXT_blend_func_separate                , GLL,  x ,  x ,  x , 1999)
> +EXT(EXT_discard_framebuffer                 , dummy_true                             ,  x ,  x , ES1, ES2, 2009)
> +EXT(EXT_blend_minmax                        , EXT_blend_minmax                       , GLL,  x , ES1, ES2, 1995)

I like the idea of this patch. It's a cleanup that needs to happen. But,
the little details confuse me.

When I see GLL, GLC, ES1, and ES2 as the entries in the version columns,
the entries confuse me because I expect the tokens to all have different
values. Otherwise, why would the tokens have different names?

I think the table would be less confusing if you used the macros
  #define x ~0
  #define Y 0
or
  #define n ~0
  #define Y 0
or
  #define n ~0
  #define y 0
or anything like that. I like the n/Y the best because the letters are
mnenomic and the contrast of uppercase to lowercase is easy to see when
scanning the table.