fix: account for tilePos.x getting out of the level boundary

[benhuangbmj]

Please describe what issue(s) this PR fixes.

levelComp.getAt returns incorrect results when tilePos.x is beyond the scope of the level.

Summary

When the tilePos is beyond the scope of the level, the getAt method should return an empty array. The tile2Hash function already accounts for tilePos.y getting outside of the level. However, it doesn't work for tilePos.x properly. I added a simple check in the getAt method without touching any other part of the code to avoid unexpected breaking behavior.

• Changeloged

[dragoncoder047]

The tile2hash function already accounts for tilePos.y getting outside of the level.

you sure about that?

https://github.com/benhuangbmj/kaplay/blob/7dfe1a634d0d821459ffcf136a6f48699a57d5c7/src/ecs/components/level/level.ts#L141

[benhuangbmj]

The tile2hash function already accounts for tilePos.y getting outside of the level.

you sure about that?

https://github.com/benhuangbmj/kaplay/blob/7dfe1a634d0d821459ffcf136a6f48699a57d5c7/src/ecs/components/level/level.ts#L141

What I meant was, suppose the level has m rows and n columns, then its tiles are indexed from 0 to m*n - 1. As long as 0 <= tilePos.x < m*n, then whenever tilePos.y >= m or tilePos.y < 0, tile2Hash will return a number that is beyond the proper index range, henceforth getAt will just return an empty array.

However, without the "0 <= tilePos.x < m*n" check, tile2Hash may potentially return an index within the proper index range even if tilePos itself is beyond the level boundary. And that's why I proposed the current fix.