Draw 2D shapes using Apple's high-speed drawing framework.

You're probably tired of me saying this: iOS is full of powerful and easy to use programming frameworks. It's true, and you've already met UIKit, SpriteKit, Core Animation, Core Motion, Core Image, Core Location, Grand Central Dispatch and more. But how would you feel if I said that we've yet to use one of the biggest, most powerful and most important frameworks of all?

Well, it's true. And in this technique project we're going to right that wrong. The framework is called Core Graphics, and it's responsible for device-independent 2D drawing – when you want to draw shapes, paths, shadows, colors or so on, you'll want Core Graphics. Being device-independent means you can draw things to the screen or draw them a PDF without having to change your code.