How to generate multiple stars using CIStarShineGenerator?

SwiftyLifestyle 0
Viewed 31

I'm looking for efficient way to generate multiple stars at random places (for example 10-15 of them). With this code below I can easily achieve one star but my question would be how to generate more than one star.

let filter = StarShineGenerator()
filter.center = CIVector(values: [CGFloat.random(in: 50.0...finalImage.size.width), CGFloat.random(in: 50.0...finalImage.size.height)], count: 2)
let ciFilter = filter.filter()
guard let ciFilter = ciFilter else { return }
let result = ciFilter.outputImage
guard let result = result else { return }
finalImage = UIImage(cgImage: context.createCGImage(result, from: CIImage(image: finalImage)!.extent)!)
core-image swift
1 Answers

The CIStarShineGenerator creates a single starburst. If you want to generate lots of them, you'd have to call it repeatedly and composite the resulting images together.

Core Image also has compositing filters that will combine images; you could use one of those to combine your different starbursts. I don't know if it would be fast enough.

You might also install your image into multiple CALayers, apply rotation and shift transforms to those layers, add them to the backing layer of a UIView, and then capture the combined view's contents into an image.

Duncan C0
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