|You don't have any items in your cart|
|Subtotal (ex. VAT)|
There has been a long standing issue with tile maps in GameMaker, where that if you scale them (or the viewport) you'll get cracks, or other tiles poking in and corrupting the display.
So the aim of this post is to show you why this happens, and how to avoid it. Some users have already figured a way around this, but don't really know the cause, so I want to also clear up what the hardware is actually doing, and why your getting these visual artifacts.