Blame view

Pods/Kingfisher/Sources/Filter.swift 5.42 KB
f2cf74c7   yangbin   1.0.20(4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
  //
  //  Filter.swift
  //  Kingfisher
  //
  //  Created by Wei Wang on 2016/08/31.
  //
  //  Copyright (c) 2018 Wei Wang <onevcat@gmail.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.
  
  
  
  import CoreImage
  import Accelerate
  
  // Reuse the same CI Context for all CI drawing.
  private let ciContext = CIContext(options: nil)
  
  /// Transformer method which will be used in to provide a `Filter`.
  public typealias Transformer = (CIImage) -> CIImage?
  
  /// Supply a filter to create an `ImageProcessor`.
  public protocol CIImageProcessor: ImageProcessor {
      var filter: Filter { get }
  }
  
  extension CIImageProcessor {
      public func process(item: ImageProcessItem, options: KingfisherOptionsInfo) -> Image? {
          switch item {
          case .image(let image):
              return image.kf.apply(filter)
          case .data(_):
              return (DefaultImageProcessor.default >> self).process(item: item, options: options)
          }
      }
  }
  
  /// Wrapper for a `Transformer` of CIImage filters.
  public struct Filter {
      
      let transform: Transformer
  
      public init(transform: @escaping Transformer) {
          self.transform = transform
      }
      
      /// Tint filter which will apply a tint color to images.
      public static var tint: (Color) -> Filter = {
          color in
          Filter(transform: { input in
              let colorFilter = CIFilter(name: "CIConstantColorGenerator")!
              colorFilter.setValue(CIColor(color: color), forKey: kCIInputColorKey)
              
              let colorImage = colorFilter.outputImage
              let filter = CIFilter(name: "CISourceOverCompositing")!
              filter.setValue(colorImage, forKey: kCIInputImageKey)
              filter.setValue(input, forKey: kCIInputBackgroundImageKey)
              #if swift(>=4.0)
              return filter.outputImage?.cropped(to: input.extent)
              #else
              return filter.outputImage?.cropping(to: input.extent)
              #endif
          })
      }
      
      public typealias ColorElement = (CGFloat, CGFloat, CGFloat, CGFloat)
      
      /// Color control filter which will apply color control change to images.
      public static var colorControl: (ColorElement) -> Filter = { arg -> Filter in
          let (brightness, contrast, saturation, inputEV) = arg
          return Filter(transform: { input in
              let paramsColor = [kCIInputBrightnessKey: brightness,
                                 kCIInputContrastKey: contrast,
                                 kCIInputSaturationKey: saturation]
              
              let paramsExposure = [kCIInputEVKey: inputEV]
              #if swift(>=4.0)
              let blackAndWhite = input.applyingFilter("CIColorControls", parameters: paramsColor)
              return blackAndWhite.applyingFilter("CIExposureAdjust", parameters: paramsExposure)
              #else
              let blackAndWhite = input.applyingFilter("CIColorControls", withInputParameters: paramsColor)
              return blackAndWhite.applyingFilter("CIExposureAdjust", withInputParameters: paramsExposure)
              #endif
          })
      }
  }
  
  // MARK: - Deprecated
  extension Filter {
      @available(*, deprecated, message: "Use init(transform:) instead.", renamed: "init(transform:)")
      public init(tranform: @escaping Transformer) {
          self.transform = tranform
      }
  }
  
  extension Kingfisher where Base: Image {
      /// Apply a `Filter` containing `CIImage` transformer to `self`.
      ///
      /// - parameter filter: The filter used to transform `self`.
      ///
      /// - returns: A transformed image by input `Filter`.
      ///
      /// - Note: Only CG-based images are supported. If any error happens during transforming, `self` will be returned.
      public func apply(_ filter: Filter) -> Image {
          
          guard let cgImage = cgImage else {
              assertionFailure("[Kingfisher] Tint image only works for CG-based image.")
              return base
          }
          
          let inputImage = CIImage(cgImage: cgImage)
          guard let outputImage = filter.transform(inputImage) else {
              return base
          }
          
          guard let result = ciContext.createCGImage(outputImage, from: outputImage.extent) else {
              assertionFailure("[Kingfisher] Can not make an tint image within context.")
              return base
          }
          
          #if os(macOS)
              return fixedForRetinaPixel(cgImage: result, to: size)
          #else
              return Image(cgImage: result, scale: base.scale, orientation: base.imageOrientation)
          #endif
      }
  
  }