Currently, I'm drawing a sf::RenderTexture on the window every time when I draw an effect. For some effects this is fine, like blur and warp and such, but certan effects really only alter a part of the texture, like this one:
Looking at the docs, however, I don't see a way to give a sprite a texture that is a smaller part of a RenderTexture. So, question is, is there a way to optimise this or do I need to draw the RenderTexture every time?
