git.r.bdr.sh - rbdr/captura/blob - Captura/Core Extensions/CGImage+resize.swift

   1 /*
   2  Copyright (C) 2024 Rubén Beltrán del Río
   3
   4  This program is free software: you can redistribute it and/or modify
   5  it under the terms of the GNU General Public License as published by
   6  the Free Software Foundation, either version 3 of the License, or
   7  (at your option) any later version.
   8
   9  This program is distributed in the hope that it will be useful,
  10  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  GNU General Public License for more details.
  13
  14  You should have received a copy of the GNU General Public License
  15  along with this program. If not, see https://captura.tranquil.systems.
  16  */
  17 import CoreGraphics
  18
  19 extension CGImage {
  20   func resize(by scale: CGFloat) -> CGImage? {
  21     let width = Int(CGFloat(self.width) / scale)
  22     let height = Int(CGFloat(self.height) / scale)
  23
  24     let bitsPerComponent = self.bitsPerComponent
  25     let colorSpace = self.colorSpace ?? CGColorSpace(name: CGColorSpace.sRGB)!
  26     let bitmapInfo = self.bitmapInfo.rawValue
  27
  28     guard
  29       let context = CGContext(
  30         data: nil, width: width, height: height, bitsPerComponent: bitsPerComponent, bytesPerRow: 0,
  31         space: colorSpace, bitmapInfo: bitmapInfo)
  32     else {
  33       return nil
  34     }
  35
  36     context.interpolationQuality = .high
  37     context.draw(self, in: CGRect(x: 0, y: 0, width: width, height: height))
  38
  39     return context.makeImage()
  40   }
  41 }