DynamicColor/Sources/DynamicGradient.swift

106 lines
3.7 KiB
Swift

/*
* DynamicColor
*
* Copyright 2015-present Yannick Loriot.
* http://yannickloriot.com
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
*/
#if os(iOS) || os(tvOS) || os(watchOS)
import UIKit
#elseif os(OSX)
import AppKit
#endif
/**
Object representing a gradient object. It allows you to manipulate colors inside different gradients and color spaces.
*/
final public class DynamicGradient {
let colors: [DynamicColor]
/**
Initializes and creates a gradient from a color array.
- Parameter colors: An array of colors.
*/
public init(colors: [DynamicColor]) {
self.colors = colors
}
/**
Returns the color palette of `amount` elements by grabbing equidistant colors.
- Parameter amount: An amount of colors to return. 2 by default.
- Parameter colorspace: The color space used to mix the colors. By default it uses the RBG color space.
- Returns: An array of DynamicColor objects with equi-distant space in the gradient.
*/
public func colorPalette(amount: UInt = 2, inColorSpace colorspace: DynamicColorSpace = .rgb) -> [DynamicColor] {
guard amount > 0 && colors.count > 0 else {
return []
}
guard colors.count > 1 else {
return (0 ..< amount).map { _ in colors[0] }
}
let increment = 1 / CGFloat(amount - 1)
return (0 ..< amount).map { pickColorAt(scale: CGFloat($0) * increment, inColorSpace: colorspace) }
}
/**
Picks up and returns the color at the given scale by interpolating the colors.
For example, given this color array `[red, green, blue]` and a scale of `0.25` you will get a kaki color.
- Parameter scale: A float value between 0.0 and 1.0.
- Parameter colorspace: The color space used to mix the colors. By default it uses the RBG color space.
- Returns: A DynamicColor object corresponding to the color at the given scale.
*/
public func pickColorAt(scale: CGFloat, inColorSpace colorspace: DynamicColorSpace = .rgb) -> DynamicColor {
guard colors.count > 1 else {
return colors.first ?? .black
}
let clippedScale = clip(scale, 0, 1)
let positions = (0 ..< colors.count).map { CGFloat($0) / CGFloat(colors.count - 1) }
var color: DynamicColor = .black
for (index, position) in positions.enumerated() {
guard clippedScale <= position else { continue }
guard clippedScale != 0 && clippedScale != 1 else {
return colors[index]
}
let previousPosition = positions[index - 1]
let weight = (clippedScale - previousPosition) / (position - previousPosition)
color = colors[index - 1].mixed(withColor: colors[index], weight: weight, inColorSpace: colorspace)
break
}
return color
}
}