No line spacing when using drawline

unless you call g.clear() or clearRect for whole screen it is indeed strange to get whole screen. just note that with true parameter it still returns modified region bu then clears it so with next call you should get undefined. The idea is that you call it with true if it is the last time you are interested in that region so next time it will be empty. you call it with false if you are just interested in current state but won't do any action (like sending it to display) so it is still modified