96 lines
2.1 KiB
Swift
96 lines
2.1 KiB
Swift
import SDL2
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import HSLuv
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public struct Colour: Equatable { let r, g, b, a: Float }
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public extension Colour
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{
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static var zero: Self { .init(r: 0, g: 0, b: 0, a: 0) }
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static var black: Self { .init(r: 0, g: 0, b: 0, a: 1) }
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static var white: Self { .init(r: 1, g: 1, b: 1, a: 1) }
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init(r: Float, g: Float, b: Float)
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{
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self.init(r: r, g: g, b: b, a: 1.0)
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}
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init(fromSdl: SDL_Color)
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{
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self.init(
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r: Float(fromSdl.r) / 0xFF,
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g: Float(fromSdl.g) / 0xFF,
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b: Float(fromSdl.b) / 0xFF,
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a: Float(fromSdl.a) / 0xFF)
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}
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init(fromRgb24: UInt32)
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{
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self.init(
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r: Float((fromRgb24 >> 16) & 0xFF) / 0xFF,
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g: Float((fromRgb24 >> 8) & 0xFF) / 0xFF,
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b: Float((fromRgb24 >> 0) & 0xFF) / 0xFF,
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a: 1)
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}
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init(fromRgba32: UInt32)
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{
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self.init(
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r: Float((fromRgba32 >> 24) & 0xFF) / 0xFF,
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g: Float((fromRgba32 >> 16) & 0xFF) / 0xFF,
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b: Float((fromRgba32 >> 8) & 0xFF) / 0xFF,
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a: Float((fromRgba32 >> 0) & 0xFF) / 0xFF)
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}
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func mix(with rhs: Colour, _ amount: Float) -> Colour
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{
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let x = amount.saturate
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return Colour(
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r: Float.lerp(r, rhs.r, x),
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g: Float.lerp(g, rhs.g, x),
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b: Float.lerp(b, rhs.b, x),
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a: Float.lerp(a, rhs.a, x))
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}
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func lighten(by: Double) -> Colour
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{
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var hue = CGFloat(), sat = CGFloat(), light = CGFloat()
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rgbToHsluv(CGFloat(r), CGFloat(g), CGFloat(b), &hue, &sat, &light)
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let gamma: CGFloat = 3.0
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light = pow((pow(light / 100, 1 / gamma) + CGFloat(by) * 0.8).saturate, gamma) * 100
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var newR = CGFloat(), newG = CGFloat(), newB = CGFloat()
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hsluvToRgb(hue, sat, light, &newR, &newG, &newB)
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return Colour(r: Float(newR), g: Float(newG), b: Float(newB), a: a)
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}
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var linear: Colour { get
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{
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Colour(
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r: linearFromSrgb(r),
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g: linearFromSrgb(g),
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b: linearFromSrgb(b),
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a: a)
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} }
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func setAlpha(_ newAlpha: Float) -> Colour
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{
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return Colour(r: r, g: g, b: b, a: newAlpha)
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}
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}
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@inline(__always) fileprivate func srgbFromLinear(_ x: Float) -> Float
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{
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return (x < 0.0031308)
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? x * 12.92
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: 1.055 * pow(x, 1.0 / 2.4) - 0.055
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}
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@inline(__always) fileprivate func linearFromSrgb(_ x: Float) -> Float
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{
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return (x < 0.04045)
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? x / 12.92
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: pow((x + 0.055) / 1.055, 2.4)
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}
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