Re: [filters] Shading language recommendation

Sent from my iPad

On Sep 5, 2012, at 1:46 PM, "Tab Atkins Jr." <jackalmage@gmail.com> wrote:

> It would perhaps be clearer if you answered my questions from earlier.
> I'll reproduce them here:
> 
> You've said that we should allow for expansion, so that future shader
> languages can be supported.  Sure, that's reasonable.  But that has
> nothing to do with what languages we require to be supported in the
> beginning.  What is *wrong* with requiring GLSL as a supported
> language, but allowing extensions such that you can expose additional
> languages?
> 
> In a previous response email to Dirk, where you
> repeatedly stressed the importance of developer choice in the matter,
> but never actually argued for why "1 required option, + additional
> choices" was bad.  Can you elaborate?  More importantly, can you
> explain why that is worse for developers than "you have to write all
> your shaders twice - once for IE and once for everyone else"?

But currently the spec doesn't REQUIRE any language. It RECOMMENDS GLSL ES and by the definition of RFC2119 that means:

3. SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course.

So that's a strong recommendation, but it's still not a requirement. It allows for support to be omitted based on the market needs of the vendor. At least 3 browser vendors present on this list support the recommended shading language on multiple platforms (desktop and mobile) and operating systems. I think it would be a shame not to capitalize on that strong direction by leaving the recommendation in the spec. 

> 
> ~TJ
>