questions about creating new shaders

[steve3d]

I'm trying to create some new post shaders, when studying the default shaders, I've found there are some keywords before if and for loop, like [branch] [unroll], but these keywords don't exists in opengl shader part.

 

So what's the meaning of these keywords? and is there any more keywords? I only found [branch] and [unroll] keywords so far.

 

and another one, why [branch] keywords only appear before some if condition, some other if condition don't have this keywords?

[alexei.garbuzenko]

In HLSL loops can be unrolled - their code would be repeated up to N times:

http://msdn.microsoft.com/en-us/library/windows/desktop/bb509602(v=vs.85).aspx

 

Conditional statements (if and switch) could be flattened or branched:

http://msdn.microsoft.com/en-us/library/windows/desktop/bb509610(v=VS.85).aspx

 

These attributes are specific for HLSL language and you should refer to its manual instead of this forum.

[steve3d]

thank you, :)