The enemy of an infinite tile engine: negative coordinates

So, another step forward in my program: I turned my tile engine to be infinite!
At least I think so. It'll probably crash or shift to negative at tilemap MaxFloat.

And 'negative' is just the word I don't like in that. Like this guy, I ran into the problem with Perlin Noise and negative values. But unlike this guy I didn't find a way to solve this problem. Yeah, it would have been cool to start at 0/0 and then go for ever to the left or to the right. But alas, my unimaginable brainz aren't lack the capacity to solve this myste riddle. At least for now. And now may be a pretty long time.

But what the heck, then the game will start at something like 1.073.281 instead of 0/0. That's still plenty of tilemaps to explore.