I fixed lerping

[VirtuGuy]

A ton of things in Friday Night Funkin's source code uses lerp. Icons on every beat, camera zooming, the freeplay menu, etc.

Though the one problem was that it worked differently on different framerates. Luckily, I have fixed this problem with a little math.

The way lerp works is that it's a little math that goes like: a + (b - a) * ratio.

Here's the lerp calculation that works for different framerates: a + (b - a) * Math.pow(ratio, (FlxG.elapsed / (1 / 60)))