added iOS source code

[wl-app.git] / iOS / Pods / Kingfisher / Sources / Filter.swift

diff --git a/iOS/Pods/Kingfisher/Sources/Filter.swift b/iOS/Pods/Kingfisher/Sources/Filter.swift
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+//
+//  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(tranform: @escaping Transformer) {
+        self.transform = tranform
+    }
+    
+    /// Tint filter which will apply a tint color to images.
+    public static var tint: (Color) -> Filter = {
+        color in
+        Filter { 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 { 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
+        }
+        
+    }
+}
+
+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
+    }
+
+}