add: ColorExtension

Sources/TsuzuKit/Extension/ColorExtension.swift

@@ -0,0 +1,64 @@
+import SwiftUI
+
+@available(iOS 13.0, *)
+@available(macOS 12.0, *)
+public extension Color {
+
+  init(
+    hue: Double,
+    saturation: Double,
+    lightness: Double,
+    opacity: Double = 1
+  ) {
+    let (h, s, b) = ColorTransformer.hslToHsb(h: hue, s: saturation, l: lightness)
+    self = Color(hue: h, saturation: s, brightness: b, opacity: opacity)
+  }
+
+  init(hex: String, opacity: Double = 1.0) {
+    let v = Int(hex, radix: 16) ?? 0
+    let r = Double(v / Int(powf(256, 2)) % 256) / 255
+    let g = Double(v / Int(powf(256, 1)) % 256) / 255
+    let b = Double(v / Int(powf(256, 0)) % 256) / 255
+    self = Color(red: r, green: g, blue: b, opacity: opacity)
+  }
+
+#if canImport(UIKit)
+  func uiColor() -> UIColor {
+    let (r, g, b, a) = getRGBA()
+    return UIColor(red: CGFloat(r), green: CGFloat(g), blue: CGFloat(b), alpha: CGFloat(a))
+  }
+#endif
+
+#if canImport(AppKit)
+  func nsColor() -> NSColor {
+    let (r, g, b, a) = getRGBA()
+    return NSColor(red: CGFloat(r), green: CGFloat(g), blue: CGFloat(b), alpha: CGFloat(a))
+  }
+#endif
+
+  func getRGBA() -> (r: Double, g: Double, b: Double, a: Double) {
+    let str = String(self.description.dropFirst())
+    let value = Int(str, radix: 16) ?? 0
+    let r = Double(value / Int(powf(256, 3)) % 256) / 255
+    let g = Double(value / Int(powf(256, 2)) % 256) / 255
+    let b = Double(value / Int(powf(256, 1)) % 256) / 255
+    let a = Double(value / Int(powf(256, 0)) % 256) / 255
+    return (r, g, b, a)
+  }
+
+  func getHSLA() -> (h: Double, s: Double, l: Double, a: Double) {
+    let (r, g, b, a) = getRGBA()
+    let (h, s, l) = ColorTransformer.rgbToHsl(r: r, g: g, b: b)
+    return (h, s, l, a)
+  }
+
+  func lighterColor() -> Color {
+    let (h, s, l, a) = getHSLA()
+    return Color(hue: h, saturation: s, lightness: min(l + 0.12, 1), opacity: a)
+  }
+
+  func darkerColor() -> Color {
+    let (h, s, l, a) = getHSLA()
+    return  Color(hue: h, saturation: s, lightness: max(l - 0.199, 0), opacity: a)
+  }
+}

Sources/TsuzuKit/Utils/ColorTransformer.swift

@@ -0,0 +1,122 @@
+
+public enum ColorTransformer {
+  static func hslToHsb(
+    h: Double,
+    s: Double,
+    l: Double
+  ) -> (h: Double, s: Double, b: Double) {
+    let (r, g, b) = hslToRgb(h: h, s: s, l: l)
+    return Self.rgbToHsb(r: r, g: g, b: b)
+  }
+
+  static func rgbToHsl(
+    r: Double,
+    g: Double,
+    b: Double
+  ) -> (h: Double, s: Double, l: Double) {
+    let (r, g, b) = (r*255, g*255, b*255)
+
+    let maxVal = max(r, g, b)
+    let minVal = min(r, g, b)
+
+    let h: Double = getHFromRGB(r: r, g: g, b: b)
+
+    let s: Double = {
+      let cnt = (maxVal + minVal) / 2
+      if cnt < 128 {
+        let a = (maxVal - minVal) / (maxVal + minVal)
+        return a.isNaN ? 0 : a
+      } else {
+        let a = (maxVal - minVal) / (510 - maxVal - minVal)
+        return a.isNaN ? 0 : a
+      }
+    }() * 255
+
+    let l = (maxVal + minVal) / 2
+
+    return (h/360, s/255, l/255)
+  }
+
+  static func hslToRgb(
+    h: Double,
+    s: Double,
+    l: Double
+  ) -> (r: Double, g: Double, b: Double) {
+    let (h, s, l) = (h*360, s*100, l*100)
+
+    let max: Double
+    let min: Double
+    if l <= 50 {
+      max = 2.55 * (l + l * (s / 100))
+      min = 2.55 * (l - l * (s / 100))
+    } else {
+      max = 2.55 * (l + (100 - l) * (s / 100))
+      min = 2.55 * (l - (100 - l) * (s / 100))
+    }
+
+    let rgb: (Double, Double, Double)
+    switch h {
+    case 0...60:
+      let g = (h / 60) * (max - min) + min
+      rgb = (max, g, min)
+    case 60...120:
+      let r = ((120 - h) / 60) * (max - min) + min
+      rgb = (r, max, min)
+    case 120...180:
+      let b = ((h - 120) / 60) * (max - min) + min
+      rgb = (min, max, b)
+    case 180...240:
+      let g = ((240 - h) / 60) * (max - min) + min
+      rgb = (min, g, max)
+    case 240...300:
+      let r = ((h - 240) / 60) * (max - min) + min
+      rgb = (r, min, max)
+    default:
+      let b = ((360 - h) / 60) * (max - min) + min
+      rgb = (max, min, b)
+    }
+    return (rgb.0 / 255, rgb.1 / 255, rgb.2 / 255)
+  }
+
+  static func rgbToHsb(
+    r: Double,
+    g: Double,
+    b: Double
+  ) -> (h: Double, s: Double, b: Double) {
+    let (r, g, b) = (r*255, g*255, b*255)
+
+    let maxVal = max(r, g, b)
+    let minVal = min(r, g, b)
+
+    let h = getHFromRGB(r: r, g: g, b: b)
+    var s = (maxVal - minVal) / maxVal * 255
+    if s.isNaN { s = 0 }
+    return (h/360, s/255, maxVal/255)
+  }
+
+  private static func getHFromRGB(r: Double, g: Double, b: Double) -> Double {
+    if r == g, g == b { return 0 }
+
+    let maxVal = max(r, g, b)
+    let minVal = min(r, g, b)
+
+    func cal(_ x: Double, max: Double, min: Double) -> Double {
+      return 60 * (x / (max - min))
+    }
+
+    var h: Double
+    switch maxVal {
+    case r:
+      h = cal(g - b, max: maxVal, min: minVal)
+      if h.isNaN { h = 0 }
+    case g:
+      h = cal(b - r, max: maxVal, min: minVal) + 120
+      if h.isNaN { h = 120 }
+    case b:
+      h = cal(r - g, max: maxVal, min: minVal) + 240
+      if h.isNaN { h = 240 }
+    default: h = 0
+    }
+    return h >= 0 ? h : h + 360
+  }
+}