I have a couple of .fx files from a Shader-Based 2D Shadows example. I want to utilize the same kind of technique with XNA 4.0's Reach profile, which if I understand correctly needs to have HLSL 2.0 shaders. I am not familiar with shaders, so obviously I need to learn HLSL, but what I'm wondering right now is how to tell what shader code is 3.0 and what is 2.0, because I need to port those shaders to 2.0 and utilize them in my project. Can FX Composer be used to know such a thing?
A sub-question - Is it possible that they would not perform well when ported to 2.0? If I want to utilize a similar effect to what is presented in the link, do I need to bump my project up to the HiDef profile and use HLSL 3.0, or should I be able to get away with 2.0?