135 lines
2.9 KiB
Swift
135 lines
2.9 KiB
Swift
//
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// InterpolatableExtensions.swift
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// lottie-swift
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//
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// Created by Brandon Withrow on 1/14/19.
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//
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import CoreGraphics
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import Foundation
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extension Color {
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// MARK: Lifecycle
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/// Initialize a new color with Hue Saturation and Value
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init(h: Double, s: Double, v: Double, a: Double) {
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let i = floor(h * 6)
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let f = h * 6 - i
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let p = v * (1 - s);
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let q = v * (1 - f * s)
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let t = v * (1 - (1 - f) * s)
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switch i.truncatingRemainder(dividingBy: 6) {
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case 0:
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r = v
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g = t
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b = p
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case 1:
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r = q
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g = v
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b = p
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case 2:
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r = p
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g = v
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b = t
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case 3:
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r = p
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g = q
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b = v
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case 4:
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r = t
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g = p
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b = v
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case 5:
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r = v
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g = p
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b = q
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default:
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r = 0
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g = 0
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b = 0
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}
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self.a = a
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}
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init(y: Double, u: Double, v: Double, a: Double) {
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// From https://www.fourcc.org/fccyvrgb.php
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r = y + 1.403 * v
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g = y - 0.344 * u
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b = y + 1.770 * u
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self.a = a
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}
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// MARK: Internal
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/// Hue Saturation Value of the color.
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var hsva: (h: Double, s: Double, v: Double, a: Double) {
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let maxValue = max(r, g, b)
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let minValue = min(r, g, b)
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var h: Double, s: Double, v: Double = maxValue
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let d = maxValue - minValue
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s = maxValue == 0 ? 0 : d / maxValue;
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if maxValue == minValue {
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h = 0; // achromatic
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} else {
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switch maxValue {
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case r: h = (g - b) / d + (g < b ? 6 : 0)
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case g: h = (b - r) / d + 2
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case b: h = (r - g) / d + 4
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default: h = maxValue
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}
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h = h / 6
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}
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return (h: h, s: s, v: v, a: a)
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}
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var yuv: (y: Double, u: Double, v: Double, a: Double) {
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/// From https://www.fourcc.org/fccyvrgb.php
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let y = 0.299 * r + 0.587 * g + 0.114 * b
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let u = -0.14713 * r - 0.28886 * g + 0.436 * b
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let v = 0.615 * r - 0.51499 * g - 0.10001 * b
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return (y: y, u: u, v: v, a: a)
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}
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}
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// MARK: - CurveVertex + Interpolatable
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extension CurveVertex: Interpolatable {
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func interpolate(to: CurveVertex, amount: CGFloat) -> CurveVertex {
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CurveVertex(
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point: point.interpolate(to: to.point, amount: amount),
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inTangent: inTangent.interpolate(to: to.inTangent, amount: amount),
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outTangent: outTangent.interpolate(to: to.outTangent, amount: amount))
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}
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}
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// MARK: - BezierPath + Interpolatable
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extension BezierPath: Interpolatable {
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func interpolate(to: BezierPath, amount: CGFloat) -> BezierPath {
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var newPath = BezierPath()
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for i in 0..<min(elements.count, to.elements.count) {
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let fromVertex = elements[i].vertex
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let toVertex = to.elements[i].vertex
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newPath.addVertex(fromVertex.interpolate(to: toVertex, amount: amount))
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}
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return newPath
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}
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}
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// MARK: - TextDocument + Interpolatable
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extension TextDocument: Interpolatable {
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func interpolate(to: TextDocument, amount: CGFloat) -> TextDocument {
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if amount == 1 {
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return to
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}
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return self
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}
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}
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