[Feature Request] Better tile draw preview

[Gamer-XP]

When drawing a tile - it's displayed over everything. It may look a bit confusing if you're actually drawing to some BG layer and it's not fully visible. I'd like to request a small improvement here: Make tile look half-transparent if it's behind other objects/tiles.

Can think of few ways to implement that:

1. Draw tile at target depth, then draw it half-transparent on top of everything. If sprite had partially transparent pixels - it may make it look a bit different, but should be not critical
2. Draw tile on top of everything. Check everything that overlaps with it on higher layers, and draw them partially transparent using drawing tile as a mask
3. Mask area around cursor so it makes higher level layers partially transparent in a small circle around current tile.