void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
void attach(FramebufferAttachment attch, Texture2D &tex, int level);
void detach(FramebufferAttachment attch);
void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
void attach(FramebufferAttachment attch, Texture2D &tex, int level);
void detach(FramebufferAttachment attch);