Lerp
Lerp is a linear interpolation microlibrary.
I got sick of copying and pasting these functions into every project, so I made a Cocoapod.
Lerp implements a Lerpable protocol on Float, Double, CGFloat, and CGPoint - mostly cribbed from this Stack Overflow post.
Examples
✓ Linear interpolation
lerp(0.5, min: 30, max: 40)
// 35
✓ Inverse linear interpolation
ilerp(35, min: 30, max: 40)
// 0.5
✓ Clamping
clamp(35, min: 30, max: 40)
// 35
clamp(25, min: 30, max: 40)
// 20
clamp(45, min: 30, max: 40)
// 40
CGPoint helpers:
CGPoint(x: 0.5, y: 0.5).lerp(min: CGPoint(x: 0.0, y: 0.0), max: CGPoint(x: 20.0, y: 40.0))
// CGPoint(x: 10.0, y: 20.0)
CGPoint(x: 0.5, y: 0.5).lerp(rect: CGRect(x: 0.0, y: 0.0, width: 20.0, height: 40.0))
// CGPoint(x: 10.0, y: 20.0)
CGPoint(x: 10.0, y: 20.0).ilerp(min: CGPoint(x: 0.0, y: 0.0), max: CGPoint(x: 20.0, y: 40.0))
// CGPoint(x: 0.5, y: 0.5)
CGPoint(x: 10.0, y: 20.0).ilerp(rect: CGRect(x: 0.0, y: 0.0, width: 20.0, height: 40.0))
// CGPoint(x: 0.5, y: 0.5)
CGPoint(x: -10.0, y: 50.0).clamp(min: CGPoint(x: 0.0, y: 0.0), max: CGPoint(x: 20.0, y: 40.0))
// CGPoint(x: 0.0, y: 40.0)
CGPoint(x: -10.0, y: 50.0).clamp(rect: CGRect(x: 0.0, y: 0.0, width: 20.0, height: 40.0))
// CGPoint(x: 0.0, y: 40.0)
CGRect helpers:
CGRect(x: 0.0, y: 0.0, width: 0.5, height: 0.5).lerp(rect: CGRect(x: 0.0, y: 0.0, width: 20.0, height: 40.0))
// CGRect(x: 0.0, y: 0.0, width: 10.0, height: 20.0)
CGRect(x: 0.0, y: 0.0, width: 10.0, height: 20.0).ilerp(rect: CGRect(x: 0.0, y: 0.0, width: 20.0, height: 40.0))
// CGRect(x: 0.0, y: 0.0, width: 0.5, height: 0.5)