Sources/Patterns/CGImage+resize.swift


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

import CoreGraphics

extension CGImage {
    func resize(size:CGSize) -> CGImage? {
        let width: Int = Int(size.width)
        let height: Int = Int(size.height)

        let bytesPerPixel = self.bitsPerPixel / self.bitsPerComponent
        let destBytesPerRow = width * bytesPerPixel

        guard let colorSpace = self.colorSpace else { return nil }
        guard let context = CGContext(data: nil, width: width, height: height, bitsPerComponent: self.bitsPerComponent, bytesPerRow: destBytesPerRow, space: colorSpace, bitmapInfo: self.alphaInfo.rawValue) else { return nil }

        context.interpolationQuality = .none
        context.draw(self, in: CGRect(x: 0, y: 0, width: width, height: height))

        return context.makeImage()
    }
}