Up until now I’ve had placeholder health bars that do their job as intended, but require a ton of manual work and take up a lot of memory. I’ve always had the goal of making the health bars work programmatically, and I finally got around to doing it. Well, version 1 at least. Have a look at how I’ve used SKShader, SKCropNode, SKShapeNode and CGPath all rendered to one final texture to make my health system work.

If you’re new to game development, you’ve probably heard of shaders but don’t quite understand them. If you’re new to SpriteKit, you’ve probably hit a few speed bumps working with shaders. Since I’m still learning more about the two, I figured it would be nice to put up a concrete example that covers cropping and effects using shaders. Specifically, we’ll cover two concepts: