Here's the first brand-new engine I've made in a while! A pen bar with a draggable node that changes a variable (otherwise known as a slider :P). This was made for an upcoming game of mine (see @CantStopWishiwashi if you are interested) to change the brightness. However, since the engine turned out so well, I decided to share it early with comments explaining how to adjust it for your own needs! As always, be sure to give credit. Doesn't matter if you're using my stuff, @griffpatch's, or someone else's. It's important to always give credit.