Add zoom onWheel + move with mouse pointer

[slawkens]

Hi,

I leave this here, just so it won't be forgotten on my drive.

It isn't meant to be merged. I just use your repo as memory so my code won't disappear. Maybe someone will find it useful, when making map editor or something similar.

The code itself isn't 100% made by me, I looked at several tutorials because I'm new to PIXI.js.

What is working?

• Zoom in and out with mouse wheel
• Move map with mouse pointer

Hope it won't be a problem to leave it here.

So. Enough explanation ;)

Thanks for inspiration!

[edceds]

This is very cool, but my repo is meant to be developed as a game, instead of a map editor, so I won't merge. I'll leave this PR open, or another branch for the map editor could exist.