Currently, the library only support loading resources from file or from memory. It will be nicer if it supports a custom file stream interface where data input can be overriden by users. Something like:
class IInputStream:
{
virtual void* readData(int size)=0;
virtual void release()=0;//called when SFML's done with this stream
};
This will give chances for things like: virtual file system, resource protection, mod (files from a mod override files from the original game...), online streaming ...
I know it's possible to load everything into memory, decrypt then feed it to sfml but for streamed resources like video or music, it defeats the purpose of streaming