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refactor UIImage extension #8

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refactor UIImage extension #8

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137 changes: 30 additions & 107 deletions GIF-Swift/iOSDevCenters+GIF.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -8,21 +8,6 @@

import UIKit
import ImageIO
// FIXME: comparison operators with optionals were removed from the Swift Standard Libary.
// Consider refactoring the code to use the non-optional operators.
fileprivate func < <T : Comparable>(lhs: T?, rhs: T?) -> Bool {
switch (lhs, rhs) {
case let (l?, r?):
return l < r
case (nil, _?):
return true
default:
return false
}
}



extension UIImage {

public class func gifImageWithData(_ data: Data) -> UIImage? {
Expand All @@ -35,12 +20,11 @@ extension UIImage {
}

public class func gifImageWithURL(_ gifUrl:String) -> UIImage? {
guard let bundleURL:URL? = URL(string: gifUrl)
else {
print("image named \"\(gifUrl)\" doesn't exist")
return nil
guard let bundleURL:URL = URL(string: gifUrl) else {
print("image named \"\(gifUrl)\" doesn't exist")
return nil
}
guard let imageData = try? Data(contentsOf: bundleURL!) else {
guard let imageData = try? Data(contentsOf: bundleURL) else {
print("image named \"\(gifUrl)\" into NSData")
return nil
}
Expand All @@ -49,10 +33,9 @@ extension UIImage {
}

public class func gifImageWithName(_ name: String) -> UIImage? {
guard let bundleURL = Bundle.main
.url(forResource: name, withExtension: "gif") else {
print("SwiftGif: This image named \"\(name)\" does not exist")
return nil
guard let bundleURL = Bundle.main.url(forResource: name, withExtension: "gif") else {
print("SwiftGif: This image named \"\(name)\" does not exist")
return nil
}
guard let imageData = try? Data(contentsOf: bundleURL) else {
print("SwiftGif: Cannot turn image named \"\(name)\" into NSData")
Expand All @@ -62,8 +45,9 @@ extension UIImage {
return gifImageWithData(imageData)
}

class func delayForImageAtIndex(_ index: Int, source: CGImageSource!) -> Double {
var delay = 0.1
private class func delayForImageAtIndex(_ index: Int, source: CGImageSource!) -> Double {
let defaultDelay = 0.032 // 30 fps
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@sachinmeesho sachinmeesho Jun 22, 2021 •
edited
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0.032 value could be even less, maybe 0.001. In my case, per frame delay was 0.02 for a gif.

var delay = defaultDelay

let cfProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil)
let gifProperties: CFDictionary = unsafeBitCast(
Expand All @@ -80,102 +64,41 @@ extension UIImage {
Unmanaged.passUnretained(kCGImagePropertyGIFDelayTime).toOpaque()), to: AnyObject.self)
}

delay = delayObject as! Double
guard let castedDelay = delayObject as? Double else { return delay }

if delay < 0.1 {
delay = 0.1
}
delay = castedDelay < defaultDelay ? defaultDelay : castedDelay

return delay
}

class func gcdForPair(_ a: Int?, _ b: Int?) -> Int {
var a = a
var b = b
if b == nil || a == nil {
if b != nil {
return b!
} else if a != nil {
return a!
} else {
return 0
}
}

if a < b {
let c = a
a = b
b = c
}

var rest: Int
while true {
rest = a! % b!

if rest == 0 {
return b!
} else {
a = b
b = rest
}
}
}

class func gcdForArray(_ array: Array<Int>) -> Int {
private class func gcdForArray(_ array: [Int]) -> Int {
if array.isEmpty {
return 1
}

var gcd = array[0]

for val in array {
gcd = UIImage.gcdForPair(val, gcd)
}

return gcd
return array.sorted(by: <).first ?? 1
}

class func animatedImageWithSource(_ source: CGImageSource) -> UIImage? {
private class func animatedImageWithSource(_ source: CGImageSource) -> UIImage? {
let count = CGImageSourceGetCount(source)
var images = [CGImage]()
var delays = [Int]()
let images = (0..<count)
.compactMap({ CGImageSourceCreateImageAtIndex(source, $0, nil) })
let delays = images
.enumerated()
.map({ Int(UIImage.delayForImageAtIndex($0.offset,source: source) * 1000) })

for i in 0..<count {
if let image = CGImageSourceCreateImageAtIndex(source, i, nil) {
images.append(image)
}

let delaySeconds = UIImage.delayForImageAtIndex(Int(i),
source: source)
delays.append(Int(delaySeconds * 1000.0)) // Seconds to ms
}

let duration: Int = {
var sum = 0

for val: Int in delays {
sum += val
}

return sum
}()
let duration = delays.reduce(0, +)

let gcd = gcdForArray(delays)
var frames = [UIImage]()

var frame: UIImage
var frameCount: Int
for i in 0..<count {
frame = UIImage(cgImage: images[Int(i)])
frameCount = Int(delays[Int(i)] / gcd)

for _ in 0..<frameCount {
frames.append(frame)
}
}

let animation = UIImage.animatedImage(with: frames,
duration: Double(duration) / 1000.0)
let frames: [UIImage] = images
.map({ UIImage(cgImage: $0) })
.enumerated()
.map({
Array(repeating: $0.element, count: Int(delays[$0.offset] / gcd) )
})
.flatMap({ $0 })

let animation = UIImage.animatedImage(with: frames, duration: Double(duration) / 1000)

return animation
}
Expand Down