I guess because of the new rendering system?
Yes, the sf::Renderer class will disappear and vertices won't be pre-transformed on the CPU anymore. Since aligning must happen after transforming... I'm stuck.
Do you have a good advice how to achieve such tasks on user side (maybe not now but if everything is finished)?
I'm afraid it's very complicated to align untransformed points. You have to take position/rotation/scale/origin in account, as well as the current view, viewport and size of the target.
