In this tutorial we are covering how to build turrets and latch them onto objects. Using this you can build a space ship game with limited turret pointing or even have a side-scroller with a character that can only aim when actually facing a direction. I put this together for a fellow member of the Game Maker Community who was having issues with this.
Please note that if you are using Game Maker 8.1 then angle_difference is unavailable to you. You can however get a script version here:
Be sure to check out my projects on Game Jolt!
Get the file here!