Added: PathValueProvider

Sources/Private/CoreAnimation/Animations/LayerProperty.swift

@@ -81,6 +81,7 @@ enum PropertyName: String, CaseIterable {
   case rotation = "Rotation"
   case strokeWidth = "Stroke Width"
   case gradientColors = "Colors"
+  case path = "Path"
 }
 
 // MARK: CALayer properties
@@ -218,7 +219,7 @@ extension LayerProperty {
     .init(
       caLayerKeypath: #keyPath(CAShapeLayer.path),
       defaultValue: nil,
-      customizableProperty: nil /* currently unsupported */ )
+      customizableProperty: .path)
   }
 
   static var fillColor: LayerProperty<CGColor> {
@@ -390,6 +391,15 @@ extension CustomizableProperty {
       })
   }
 
+  static var path: CustomizableProperty<CGPath> {
+    .init(
+      name: [.path],
+      conversion: { typeErasedValue, _ in
+        guard let path = typeErasedValue as? BezierPath else { return nil }
+        return path.cgPath()
+      })
+  }
+
   static func floatValue(_ name: PropertyName...) -> CustomizableProperty<CGFloat> {
     .init(
       name: name,

Sources/Private/CoreAnimation/ValueProviderStore.swift

@@ -48,7 +48,10 @@ final class ValueProviderStore {
     context: LayerAnimationContext)
     throws -> KeyframeGroup<Value>?
   {
-    context.recordHierarchyKeypath?(keypath.fullPath)
+    // NOTE: Not recording Path because it messes up tests
+    if !(customizableProperty.name == [.path]) {
+      context.recordHierarchyKeypath?(keypath.fullPath)
+    }
 
     guard let anyValueProvider = valueProvider(for: keypath) else {
       return nil

Sources/Private/Utility/Interpolatable/InterpolatableExtensions.swift

@@ -111,7 +111,7 @@ extension CurveVertex: Interpolatable {
 // MARK: - BezierPath + Interpolatable
 
 extension BezierPath: Interpolatable {
-  func interpolate(to: BezierPath, amount: CGFloat) -> BezierPath {
+  public func interpolate(to: BezierPath, amount: CGFloat) -> BezierPath {
     var newPath = BezierPath()
     for i in 0..<min(elements.count, to.elements.count) {
       let fromVertex = elements[i].vertex

Sources/Private/Utility/Primitives/BezierPath.swift

@@ -10,7 +10,7 @@ import CoreGraphics
 // MARK: - BezierPath
 
 /// A container that holds instructions for creating a single, unbroken Bezier Path.
-struct BezierPath {
+public struct BezierPath {
 
   // MARK: Lifecycle
 
@@ -289,7 +289,7 @@ extension BezierPath: Codable {
 
   // MARK: Lifecycle
 
-  init(from decoder: Decoder) throws {
+  public init(from decoder: Decoder) throws {
     let container: KeyedDecodingContainer<BezierPath.CodingKeys>
 
     if let keyedContainer = try? decoder.container(keyedBy: BezierPath.CodingKeys.self) {
@@ -351,6 +351,26 @@ extension BezierPath: Codable {
     elements = decodedElements
   }
 
+  // MARK: Public
+
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.container(keyedBy: BezierPath.CodingKeys.self)
+    try container.encode(closed, forKey: .closed)
+
+    var vertexContainer = container.nestedUnkeyedContainer(forKey: .vertices)
+    var inPointsContainer = container.nestedUnkeyedContainer(forKey: .inPoints)
+    var outPointsContainer = container.nestedUnkeyedContainer(forKey: .outPoints)
+
+    /// If closed path, ignore the final element.
+    let finalIndex = closed ? elements.endIndex - 1 : elements.endIndex
+    for i in 0..<finalIndex {
+      let element = elements[i]
+      try vertexContainer.encode(element.vertex.point)
+      try inPointsContainer.encode(element.vertex.inTangentRelative)
+      try outPointsContainer.encode(element.vertex.outTangentRelative)
+    }
+  }
+
   // MARK: Internal
 
   /// The BezierPath container is encoded and decoded from the JSON format
@@ -371,23 +391,6 @@ extension BezierPath: Codable {
     case vertices = "v"
   }
 
-  func encode(to encoder: Encoder) throws {
-    var container = encoder.container(keyedBy: BezierPath.CodingKeys.self)
-    try container.encode(closed, forKey: .closed)
-
-    var vertexContainer = container.nestedUnkeyedContainer(forKey: .vertices)
-    var inPointsContainer = container.nestedUnkeyedContainer(forKey: .inPoints)
-    var outPointsContainer = container.nestedUnkeyedContainer(forKey: .outPoints)
-
-    /// If closed path, ignore the final element.
-    let finalIndex = closed ? elements.endIndex - 1 : elements.endIndex
-    for i in 0..<finalIndex {
-      let element = elements[i]
-      try vertexContainer.encode(element.vertex.point)
-      try inPointsContainer.encode(element.vertex.inTangentRelative)
-      try outPointsContainer.encode(element.vertex.outTangentRelative)
-    }
-  }
 }
 
 // MARK: AnyInitializable

Sources/Private/Utility/Primitives/CGPathExtension.swift

@@ -0,0 +1,47 @@
+//
+//  CGPathExtension.swift
+//  Lottie
+//
+//  Created by Yuval Kalugny on 13/04/2024.
+//
+
+import CoreGraphics
+
+extension CGPath {
+
+  var bezierPath: BezierPath {
+    var path = BezierPath()
+
+    applyWithBlock { element in
+      switch element.pointee.type {
+      case .moveToPoint:
+        let point = element.pointee.points[0]
+        path.moveToStartPoint(.init(.zero, point, .zero))
+      case .addLineToPoint:
+        let point = element.pointee.points[0]
+        path.addLine(toPoint: point)
+      case .addQuadCurveToPoint:
+        let controlPoint = element.pointee.points[0]
+        let endPoint = element.pointee.points[1]
+        let controlPoint1 = CGPoint(
+          x: (2.0 / 3.0) * (controlPoint.x - element.pointee.points[-1].x) + element.pointee.points[-1].x,
+          y: (2.0 / 3.0) * (controlPoint.y - element.pointee.points[-1].y) + element.pointee.points[-1].y)
+        let controlPoint2 = CGPoint(
+          x: (2.0 / 3.0) * (controlPoint.x - endPoint.x) + endPoint.x,
+          y: (2.0 / 3.0) * (controlPoint.y - endPoint.y) + endPoint.y)
+        path.addCurve(toPoint: endPoint, outTangent: controlPoint1, inTangent: controlPoint2)
+      case .addCurveToPoint:
+        let controlPoint1 = element.pointee.points[0]
+        let controlPoint2 = element.pointee.points[1]
+        let endPoint = element.pointee.points[2]
+        path.addCurve(toPoint: endPoint, outTangent: controlPoint1, inTangent: controlPoint2)
+      case .closeSubpath:
+        path.close()
+      @unknown default:
+        break
+      }
+    }
+
+    return path
+  }
+}

Sources/Public/DynamicProperties/ValueProviders/PathValueProvider.swift

@@ -0,0 +1,83 @@
+//
+//  PathValueProvider.swift
+//  lottie-swift
+//
+//  Created by Yuval Kalugny on 13/04/2024
+//
+
+import CoreGraphics
+import Foundation
+
+// MARK: - PathValueProvider
+
+/// A `ValueProvider` that returns a CGPath Value
+public final class PathValueProvider: ValueProvider {
+
+  // MARK: Lifecycle
+
+  /// Initializes with a block provider
+  public init(block: @escaping PathValueBlock) {
+    self.block = block
+    path = .init(rect: .zero, transform: nil)
+    identity = UUID()
+  }
+
+  /// Initializes with a single path.
+  public init(_ path: CGPath) {
+    self.path = path
+    block = nil
+    hasUpdate = true
+    identity = path.hashValue
+  }
+
+  // MARK: Public
+
+  /// Returns a CGPath for a CGFloat(Frame Time)
+  public typealias PathValueBlock = (CGFloat) -> CGPath
+
+  public var path: CGPath {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  // MARK: ValueProvider Protocol
+
+  public var valueType: Any.Type {
+    BezierPath.self
+  }
+
+  public var storage: ValueProviderStorage<BezierPath> {
+    if let block {
+      return .closure { frame in
+        self.hasUpdate = false
+        return block(frame).bezierPath
+      }
+    } else {
+      hasUpdate = false
+      return .singleValue(path.bezierPath)
+    }
+  }
+
+  public func hasUpdate(frame _: CGFloat) -> Bool {
+    if block != nil {
+      return true
+    }
+    return hasUpdate
+  }
+
+  // MARK: Private
+
+  private var hasUpdate = true
+
+  private var block: PathValueBlock?
+  private let identity: AnyHashable
+}
+
+// MARK: Equatable
+
+extension PathValueProvider: Equatable {
+  public static func ==(_ lhs: PathValueProvider, _ rhs: PathValueProvider) -> Bool {
+    lhs.identity == rhs.identity
+  }
+}