Perhaps I don't understand, but I'm pretty sure it is (0, 0) by default. If you translate to some point then you would just translate the opposite to get to 0. For example:

Thanks, I understand how one can translate relatively and use the matrix stack.

To the best of my knowledge you would have to track the translations with variables. For example:

Ah, I think I just understood what you meant, if Processing stores the current translateX or translateY without having to track it yourself. As far as I know it doesn't, maybe phi.lho would know

If you're using the JAVA2D renderer (which you are by default), you can get the translation X and Y like this:

Thanks, that works! I wonder what the syntax means though. Those two statements are black boxes to me.