Why does AwesomeBump require OpenGL 4.0?

[megad...@gmail.com]

I'd like to know the technical reason(s) for needing to use OpenGL 4.0.

[K Kolasinski]

Basically, there are no reasons, I started the project with openGL 4.0 because I  didn't suspect that it would be a problem for many people :/ 

Talking about technical reasons:

Tessellation requires 4.0, but this feature is not necessary. I also use GLSL subroutines (extremelly usefull feature!) which require 4.0 version, but they can be replaced by "#ifdef/#endif" statements in code. So, I think all the features of AB (except tessellation) can be reproduced with GL3.3 version. Unfortunately this would require a lot of additional work. If you find someone who would like to rewrite almost 20% of AB code I'd be glad :)