World border

[lukeeey]

This pull request implements support for the world border. It can be difficult as there is no support in bedrock edition for this feature.

Currently implemented

• A warning when the player is near the edge of the world border
  

TODO

• Implement something that acts as a makeshift world border thats stops players going passed. I have an idea.

[ZebulanStanphill]

Since the Java Edition world border only works in full-block increments (even when it appears half-way in a block), you could simulate the effects of the world border by interpreting the ring of blocks at the bottom of the world border as border blocks. Border blocks (despite their wall-like appearance) take up a full block... actually, their bounding box extends infinitely above and below them, making them the closest analog to a world border in Bedrock Edition.

The only issue is that they were an Education Edition exclusive up until recently. Luckily, they are being added to standard Bedrock in the 1.16 update. So you'll have to wait for that to release before you can use them.

If, for whatever reason, you can't use that approach, a somewhat more obtrusive approach would be to interpret all solid blocks on the world border as bedrock (the block), and all transparent blocks as barriers.

[lukeeey]

@ZebulanStanphill Message me on Discord (lukeeey#2013)