git.r.bdr.sh - rbdr/patterns/blob - Sources/Patterns/TileImage.swift

   1 import CoreGraphics
   2
   3 struct TileImage {
   4   static func image(_ design: TileDesign, pixelSize: CGFloat, foregroundColor: CGColor? = nil, backgroundColor: CGColor? = nil) -> CGImage {
   5
   6     let fg = foregroundColor ?? .init(red: 0, green: 0, blue: 0, alpha: 255)
   7     let bg = backgroundColor ?? .init(red: 255, green: 255, blue: 255, alpha: 255)
   8
   9     // Convert the array to image data
  10
  11     let pixels: [UInt8] = design.pixels().map({ x in
  12       var color = bg
  13       if x == 0 {
  14         color = fg
  15       }
  16       let components = color.components ?? [0,0,0,1]
  17       return components.map({ c in
  18         UInt8(round(c * 255))
  19       })
  20     }).reduce([], +)
  21
  22     // Generate the image
  23
  24     let pointer = UnsafeMutablePointer<UInt8>.allocate(capacity: pixels.count)
  25     pointer.initialize(from: pixels, count: pixels.count)
  26     let width = 8.0
  27     let height = 8.0
  28     let bitsPerComponent = 8
  29     let componentCount = 4
  30     let bitsPerPixel = bitsPerComponent * componentCount
  31     let colorSpace = CGColorSpaceCreateDeviceRGB()
  32
  33     let bitmapInfo = CGBitmapInfo([.byteOrderDefault, CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedLast.rawValue)])
  34     let provider = CGDataProvider(dataInfo: nil, data: pointer, size: Int(width * height * 4)) { _, _, _ in
  35       return
  36     }!
  37
  38     let image = CGImage(
  39       width: Int(width),
  40       height: Int(height),
  41       bitsPerComponent: bitsPerComponent,
  42       bitsPerPixel: bitsPerPixel,
  43       bytesPerRow: Int(width) * componentCount,
  44       space: colorSpace,
  45       bitmapInfo: bitmapInfo,
  46       provider: provider,
  47       decode: nil, shouldInterpolate: false, intent: CGColorRenderingIntent.defaultIntent)!
  48
  49     return image.resize(size: CGSize(width: width * pixelSize, height: height * pixelSize)) ?? image
  50   }
  51 }