If by pixel clamping, you mean the fact that every pixel is on a perfect grid, then yes it's a built in feature...sort of.
That's acheived by rendering everything at a lower resolution and then scaling it up before showing it to the player. It's pretty easy to do in Godot, but it requires setting the size you want to render at, and the size of the window (size you want to show to the player). As well as stretch modes. It's barely a minute of config (and the concepts involved aren't that complicated either) , but it's not plug and play.
