Reflection interfaces

[Rico Schüller]

Am 19.10.2010 12:25, schrieb Henri Verbeet:
> 2010/10/18 Rico Schüller<kgbricola at web.de>:
>    
>> What's the preferred way to implement the different interfaces?
>>
>> 1. Implement a parser which parses the shader (RDEF, STAT), and implement 4
>> independent interfaces (each in its own dll). Only reuse the parser.
>> 2. Like 1, but all 4 implementations have there own parser, which leads to a
>> lot of duplicated code. But it is the most flexible way. It could easily
>> parse all possible shader blobs (theoretically they could differ from
>> version to version, I have no test for that, yet).
>> 3. Forward all interfaces to d3dcompiler_43.dll and this will contain all
>> interfaces and the parser. This way the codebase is the smallest possible
>> one, but it will offer all interfaces, which isn't what native does. Also
>> all further interfaces would go to d3dcompiler_43.dll. This could get
>> tricky.
>>
>>      
> I'm not sure. The problem with 3 is that it will prevent using the
> native d3dcompiler to work around e.g. the missing HLSL compiler
> because it doesn't implement ID3D10ShaderReflection etc. Perhaps we
> don't care in the long term, but at least in the short term that would
> be a problem. Option 1 would require d3dcompiler to have some private
> interface or entry point, and you'd still have the same problem as
> with option 3. Option 2 leads to duplicated code.
>
> There may be an option 4 though, which would be to implement the older
> interfaces on top of ID3D11ShaderReflection. I.e., you'd use the
> information you get from the ID3D11ShaderReflection interface to
> construct constant buffers and variables for the other interfaces,
> instead of parsing the shader bytecode yourself. It would need some
> investigation to determine how feasible this option is.
>
>    
Yeah option 4 sounds very well. The problem I see with that is if there 
is a newer interface that adds a new interface function where the values 
couldn't be quarried by an older one. (I'm not sure if this would 
happen.) Then we would have to move the code to the newest function.

I guess that older functions/variable will be always there in newer 
interfaces. But if it is really a showstopper we could move from option 
4 to option 3 if that would really be required.

So we start with option 4 and implement the ID3D11ShaderReflection 
interface in d3dcompiler_43.

Any other opinions?

Cheers
Rico