IOS uses Layer Masking to create an irregular progress bar

Have you ever seen an irregular progress bar like this? Like this:

Let’s look at its layer first:

The darker layer is the bottom layer, which we label as 1, and the lighter layer, which we label as 2, looks like a simple overlay of layers, but the difficulty is how to make layer 2 show only what we want it to show, for example, at 45%, layer 2 shows only part of it, like this:

The answer is Layer Masking, which is Layer Masking. So what is a layer mask? There are too many materials on the Internet. Here is a brief description, as shown below:

A layer mask looks like a specially shaped image matter. you might have played with silly Putty prints as a kid, like this:

Here is the Demo address: github.com/zsading/Gif… If you like, don’t forget star. Enjoy 🙂