Thanks for the awesome advice! I have never thought about the option of using the ultimate all knowing search engine. Maybe I need to improve my googling skills but all I found was code that I never managed to integrate into SFML. It seems like there is plenty out there, the sort of sudo GLSL code that works with LOVE, unity or whatever.
My understanding of GLSL is still minimal and I'm not able to migrate those code snippets to works with my C++ SFML project. That is the reason I came to this forum to ask if anybody has or knows about something I can use.