jellyflood/Shared/BlurHashKit/ColourSpace.swift

26 lines
778 B
Swift
Executable File

//
// Swiftfin is subject to the terms of the Mozilla Public
// License, v2.0. If a copy of the MPL was not distributed with this
// file, you can obtain one at https://mozilla.org/MPL/2.0/.
//
// Copyright (c) 2022 Jellyfin & Jellyfin Contributors
//
import Foundation
func signPow(_ value: Float, _ exp: Float) -> Float {
copysign(pow(abs(value), exp), value)
}
func linearTosRGB(_ value: Float) -> Int {
let v = max(0, min(1, value))
if v <= 0.0031308 { return Int(v * 12.92 * 255 + 0.5) }
else { return Int((1.055 * pow(v, 1 / 2.4) - 0.055) * 255 + 0.5) }
}
func sRGBToLinear<Type: BinaryInteger>(_ value: Type) -> Float {
let v = Float(Int64(value)) / 255
if v <= 0.04045 { return v / 12.92 }
else { return pow((v + 0.055) / 1.055, 2.4) }
}