GLEGram 12.5 — Initial public release

Based on Swiftgram 12.5 (Telegram iOS 12.5).
All GLEGram features ported and organized in GLEGram/ folder.

Features: Ghost Mode, Saved Deleted Messages, Content Protection Bypass,
Font Replacement, Fake Profile, Chat Export, Plugin System, and more.

See CHANGELOG_12.5.md for full details.

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Extensions/ItemsExtension.swift

@@ -0,0 +1,97 @@
+//
+//  ItemsExtension.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/18/19.
+//
+
+import Foundation
+
+// MARK: - NodeTree
+
+final class NodeTree {
+  var rootNode: AnimatorNode? = nil
+  var transform: ShapeTransform? = nil
+  var renderContainers: [ShapeContainerLayer] = []
+  var paths: [PathOutputNode] = []
+  var childrenNodes: [AnimatorNode] = []
+}
+
+extension Array where Element == ShapeItem {
+  func initializeNodeTree() -> NodeTree {
+
+    let nodeTree = NodeTree()
+
+    for item in self {
+      guard item.hidden == false, item.type != .unknown else { continue }
+      if let fill = item as? Fill {
+        let node = FillNode(parentNode: nodeTree.rootNode, fill: fill)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let stroke = item as? Stroke {
+        let node = StrokeNode(parentNode: nodeTree.rootNode, stroke: stroke)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let gradientFill = item as? GradientFill {
+        let node = GradientFillNode(parentNode: nodeTree.rootNode, gradientFill: gradientFill)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let gradientStroke = item as? GradientStroke {
+        let node = GradientStrokeNode(parentNode: nodeTree.rootNode, gradientStroke: gradientStroke)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let ellipse = item as? Ellipse {
+        let node = EllipseNode(parentNode: nodeTree.rootNode, ellipse: ellipse)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let rect = item as? Rectangle {
+        let node = RectangleNode(parentNode: nodeTree.rootNode, rectangle: rect)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let star = item as? Star {
+        switch star.starType {
+        case .none:
+          continue
+        case .polygon:
+          let node = PolygonNode(parentNode: nodeTree.rootNode, star: star)
+          nodeTree.rootNode = node
+          nodeTree.childrenNodes.append(node)
+        case .star:
+          let node = StarNode(parentNode: nodeTree.rootNode, star: star)
+          nodeTree.rootNode = node
+          nodeTree.childrenNodes.append(node)
+        }
+      } else if let shape = item as? Shape {
+        let node = ShapeNode(parentNode: nodeTree.rootNode, shape: shape)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let trim = item as? Trim {
+        let node = TrimPathNode(parentNode: nodeTree.rootNode, trim: trim, upstreamPaths: nodeTree.paths)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+      } else if let xform = item as? ShapeTransform {
+        nodeTree.transform = xform
+        continue
+      } else if let group = item as? Group {
+
+        let tree = group.items.initializeNodeTree()
+        let node = GroupNode(name: group.name, parentNode: nodeTree.rootNode, tree: tree)
+        nodeTree.rootNode = node
+        nodeTree.childrenNodes.append(node)
+        /// Now add all child paths to current tree
+        nodeTree.paths.append(contentsOf: tree.paths)
+        nodeTree.renderContainers.append(node.container)
+      }
+
+      if let pathNode = nodeTree.rootNode as? PathNode {
+        //// Add path container to the node tree
+        nodeTree.paths.append(pathNode.pathOutput)
+      }
+
+      if let renderNode = nodeTree.rootNode as? RenderNode {
+        nodeTree.renderContainers.append(ShapeRenderLayer(renderer: renderNode.renderer))
+      }
+    }
+    return nodeTree
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/NodeProperty.swift

@@ -0,0 +1,55 @@
+//
+//  NodeProperty.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+
+/// A node property that holds a reference to a T ValueProvider and a T ValueContainer.
+class NodeProperty<T>: AnyNodeProperty {
+
+  // MARK: Lifecycle
+
+  init(provider: AnyValueProvider) {
+    valueProvider = provider
+    originalValueProvider = valueProvider
+    typedContainer = ValueContainer<T>(provider.value(frame: 0) as! T)
+    typedContainer.setNeedsUpdate()
+  }
+
+  // MARK: Internal
+
+  var valueProvider: AnyValueProvider
+  var originalValueProvider: AnyValueProvider
+
+  var valueType: Any.Type { T.self }
+
+  var value: T {
+    typedContainer.outputValue
+  }
+
+  var valueContainer: AnyValueContainer {
+    typedContainer
+  }
+
+  func needsUpdate(frame: CGFloat) -> Bool {
+    valueContainer.needsUpdate || valueProvider.hasUpdate(frame: frame)
+  }
+
+  func setProvider(provider: AnyValueProvider) {
+    guard provider.valueType == valueType else { return }
+    valueProvider = provider
+    valueContainer.setNeedsUpdate()
+  }
+
+  func update(frame: CGFloat) {
+    typedContainer.setValue(valueProvider.value(frame: frame), forFrame: frame)
+  }
+
+  // MARK: Fileprivate
+
+  fileprivate var typedContainer: ValueContainer<T>
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/Protocols/AnyNodeProperty.swift

@@ -0,0 +1,50 @@
+//
+//  AnyNodeProperty.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+
+// MARK: - AnyNodeProperty
+
+/// A property of a node. The node property holds a provider and a container
+protocol AnyNodeProperty {
+
+  /// Returns true if the property needs to recompute its stored value
+  func needsUpdate(frame: CGFloat) -> Bool
+
+  /// Updates the property for the frame
+  func update(frame: CGFloat)
+
+  /// The stored value container for the property
+  var valueContainer: AnyValueContainer { get }
+
+  /// The value provider for the property
+  var valueProvider: AnyValueProvider { get }
+
+  /// The original value provider for the property
+  var originalValueProvider: AnyValueProvider { get }
+
+  /// The Type of the value provider
+  var valueType: Any.Type { get }
+
+  /// Sets the value provider for the property.
+  func setProvider(provider: AnyValueProvider)
+}
+
+extension AnyNodeProperty {
+
+  /// Returns the most recently computed value for the keypath, returns nil if property wasn't found
+  func getValueOfType<T>() -> T? {
+    valueContainer.value as? T
+  }
+
+  /// Returns the most recently computed value for the keypath, returns nil if property wasn't found
+  func getValue() -> Any? {
+    valueContainer.value
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/Protocols/AnyValueContainer.swift

@@ -0,0 +1,26 @@
+//
+//  AnyValueContainer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+
+/// The container for the value of a property.
+protocol AnyValueContainer: AnyObject {
+
+  /// The stored value of the container
+  var value: Any { get }
+
+  /// Notifies the provider that it should update its container
+  func setNeedsUpdate()
+
+  /// When true the container needs to have its value updated by its provider
+  var needsUpdate: Bool { get }
+
+  /// The frame time of the last provided update
+  var lastUpdateFrame: CGFloat { get }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/Protocols/KeypathSearchable.swift

@@ -0,0 +1,24 @@
+//
+//  KeypathSettable.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 2/4/19.
+//
+
+import Foundation
+import QuartzCore
+
+/// Protocol that provides keypath search functionality. Returns all node properties associated with a keypath.
+protocol KeypathSearchable {
+
+  /// The name of the Keypath
+  var keypathName: String { get }
+
+  /// A list of properties belonging to the keypath.
+  var keypathProperties: [String: AnyNodeProperty] { get }
+
+  /// Children Keypaths
+  var childKeypaths: [KeypathSearchable] { get }
+
+  var keypathLayer: CALayer? { get }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/Protocols/NodePropertyMap.swift

@@ -0,0 +1,44 @@
+//
+//  NodePropertyMap.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/21/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - NodePropertyMap
+
+protocol NodePropertyMap {
+  var properties: [AnyNodeProperty] { get }
+}
+
+extension NodePropertyMap {
+
+  var childKeypaths: [KeypathSearchable] {
+    []
+  }
+
+  var keypathLayer: CALayer? {
+    nil
+  }
+
+  /// Checks if the node's local contents need to be rebuilt.
+  func needsLocalUpdate(frame: CGFloat) -> Bool {
+    for property in properties {
+      if property.needsUpdate(frame: frame) {
+        return true
+      }
+    }
+    return false
+  }
+
+  /// Rebuilds only the local nodes that have an update for the frame
+  func updateNodeProperties(frame: CGFloat) {
+    properties.forEach { property in
+      property.update(frame: frame)
+    }
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/ValueContainer.swift

@@ -0,0 +1,47 @@
+//
+//  ValueContainer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+
+/// A container for a node value that is Typed to T.
+class ValueContainer<T>: AnyValueContainer {
+
+  // MARK: Lifecycle
+
+  init(_ value: T) {
+    outputValue = value
+  }
+
+  // MARK: Internal
+
+  private(set) var lastUpdateFrame = CGFloat.infinity
+
+  fileprivate(set) var needsUpdate = true
+
+  var value: Any {
+    outputValue as Any
+  }
+
+  var outputValue: T {
+    didSet {
+      needsUpdate = false
+    }
+  }
+
+  func setValue(_ value: Any, forFrame: CGFloat) {
+    if let typedValue = value as? T {
+      needsUpdate = false
+      lastUpdateFrame = forFrame
+      outputValue = typedValue
+    }
+  }
+
+  func setNeedsUpdate() {
+    needsUpdate = true
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/ValueProviders/GroupInterpolator.swift

@@ -0,0 +1,39 @@
+//
+//  KeyframeGroupInterpolator.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/22/19.
+//
+
+import CoreGraphics
+import Foundation
+
+/// A value provider that produces an array of values from an array of Keyframe Interpolators
+final class GroupInterpolator<ValueType>: ValueProvider where ValueType: Interpolatable {
+
+  // MARK: Lifecycle
+
+  /// Initialize with an array of array of keyframes.
+  init(keyframeGroups: ContiguousArray<ContiguousArray<Keyframe<ValueType>>>) {
+    keyframeInterpolators = ContiguousArray(keyframeGroups.map({ KeyframeInterpolator(keyframes: $0) }))
+  }
+
+  // MARK: Internal
+
+  let keyframeInterpolators: ContiguousArray<KeyframeInterpolator<ValueType>>
+
+  var valueType: Any.Type {
+    [ValueType].self
+  }
+
+  var storage: ValueProviderStorage<[ValueType]> {
+    .closure { frame in
+      self.keyframeInterpolators.map({ $0.value(frame: frame) as! ValueType })
+    }
+  }
+
+  func hasUpdate(frame: CGFloat) -> Bool {
+    let updated = keyframeInterpolators.first(where: { $0.hasUpdate(frame: frame) })
+    return updated != nil
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/ValueProviders/KeyframeInterpolator.swift

@@ -0,0 +1,253 @@
+//
+//  KeyframeInterpolator.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/15/19.
+//
+
+import CoreGraphics
+import Foundation
+
+// MARK: - KeyframeInterpolator
+
+/// A value provider that produces a value at Time from a group of keyframes
+final class KeyframeInterpolator<ValueType>: ValueProvider where ValueType: AnyInterpolatable {
+
+  // MARK: Lifecycle
+
+  init(keyframes: ContiguousArray<Keyframe<ValueType>>) {
+    self.keyframes = keyframes
+  }
+
+  // MARK: Internal
+
+  let keyframes: ContiguousArray<Keyframe<ValueType>>
+
+  var valueType: Any.Type {
+    ValueType.self
+  }
+
+  var storage: ValueProviderStorage<ValueType> {
+    .closure { [self] frame in
+      // First set the keyframe span for the frame.
+      updateSpanIndices(frame: frame)
+      lastUpdatedFrame = frame
+      // If only one keyframe return its value
+      let progress: CGFloat
+      let value: ValueType
+
+      if
+        let leading = leadingKeyframe,
+        let trailing = trailingKeyframe
+      {
+        /// We have leading and trailing keyframe.
+        progress = leading.interpolatedProgress(trailing, keyTime: frame)
+        value = leading.interpolate(to: trailing, progress: progress)
+      } else if let leading = leadingKeyframe {
+        progress = 0
+        value = leading.value
+      } else if let trailing = trailingKeyframe {
+        progress = 1
+        value = trailing.value
+      } else {
+        /// Satisfy the compiler.
+        progress = 0
+        value = keyframes[0].value
+      }
+      return value
+    }
+  }
+
+  /// Returns true to trigger a frame update for this interpolator.
+  ///
+  /// An interpolator will be asked if it needs to update every frame.
+  /// If the interpolator needs updating it will be asked to compute its value for
+  /// the given frame.
+  ///
+  /// Cases a keyframe should not be updated:
+  /// - If time is in span and leading keyframe is hold
+  /// - If time is after the last keyframe.
+  /// - If time is before the first keyframe
+  ///
+  /// Cases for updating a keyframe:
+  /// - If time is in the span, and is not a hold
+  /// - If time is outside of the span, and there are more keyframes
+  /// - If a value delegate is set
+  /// - If leading and trailing are both nil.
+  func hasUpdate(frame: CGFloat) -> Bool {
+    if lastUpdatedFrame == nil {
+      return true
+    }
+
+    if
+      let leading = leadingKeyframe,
+      trailingKeyframe == nil,
+      leading.time < frame
+    {
+      /// Frame is after bounds of keyframes
+      return false
+    }
+    if
+      let trailing = trailingKeyframe,
+      leadingKeyframe == nil,
+      frame < trailing.time
+    {
+      /// Frame is before bounds of keyframes
+      return false
+    }
+    if
+      let leading = leadingKeyframe,
+      let trailing = trailingKeyframe,
+      leading.isHold,
+      leading.time < frame,
+      frame < trailing.time
+    {
+      return false
+    }
+    return true
+  }
+
+  // MARK: Fileprivate
+
+  fileprivate var lastUpdatedFrame: CGFloat?
+
+  fileprivate var leadingIndex: Int? = nil
+  fileprivate var trailingIndex: Int? = nil
+  fileprivate var leadingKeyframe: Keyframe<ValueType>? = nil
+  fileprivate var trailingKeyframe: Keyframe<ValueType>? = nil
+
+  /// Finds the appropriate Leading and Trailing keyframe index for the given time.
+  fileprivate func updateSpanIndices(frame: CGFloat) {
+    guard keyframes.count > 0 else {
+      leadingIndex = nil
+      trailingIndex = nil
+      leadingKeyframe = nil
+      trailingKeyframe = nil
+      return
+    }
+
+    // This function searches through the array to find the span of two keyframes
+    // that contain the current time.
+    //
+    // We could use Array.first(where:) but that would search through the entire array
+    // each frame.
+    // Instead we track the last used index and search either forwards or
+    // backwards from there. This reduces the iterations and complexity from
+    //
+    // O(n), where n is the length of the sequence to
+    // O(n), where n is the number of items after or before the last used index.
+    //
+
+    if keyframes.count == 1 {
+      /// Only one keyframe. Set it as first and move on.
+      leadingIndex = 0
+      trailingIndex = nil
+      leadingKeyframe = keyframes[0]
+      trailingKeyframe = nil
+      return
+    }
+
+    /// Sets the initial keyframes. This is often only needed for the first check.
+    if
+      leadingIndex == nil &&
+      trailingIndex == nil
+    {
+      if frame < keyframes[0].time {
+        /// Time is before the first keyframe. Set it as the trailing.
+        trailingIndex = 0
+      } else {
+        /// Time is after the first keyframe. Set the keyframe and the trailing.
+        leadingIndex = 0
+        trailingIndex = 1
+      }
+    }
+
+    if
+      let currentTrailing = trailingIndex,
+      keyframes[currentTrailing].time <= frame
+    {
+      /// Time is after the current span. Iterate forward.
+      var newLeading = currentTrailing
+      var keyframeFound = false
+      while !keyframeFound {
+
+        leadingIndex = newLeading
+        trailingIndex = keyframes.validIndex(newLeading + 1)
+
+        guard let trailing = trailingIndex else {
+          /// We have reached the end of our keyframes. Time is after the last keyframe.
+          keyframeFound = true
+          continue
+        }
+        if frame < keyframes[trailing].time {
+          /// Keyframe in current span.
+          keyframeFound = true
+          continue
+        }
+        /// Advance the array.
+        newLeading = trailing
+      }
+
+    } else if
+      let currentLeading = leadingIndex,
+      frame < keyframes[currentLeading].time
+    {
+
+      /// Time is before the current span. Iterate backwards
+      var newTrailing = currentLeading
+
+      var keyframeFound = false
+      while !keyframeFound {
+
+        leadingIndex = keyframes.validIndex(newTrailing - 1)
+        trailingIndex = newTrailing
+
+        guard let leading = leadingIndex else {
+          /// We have reached the end of our keyframes. Time is after the last keyframe.
+          keyframeFound = true
+          continue
+        }
+        if keyframes[leading].time <= frame {
+          /// Keyframe in current span.
+          keyframeFound = true
+          continue
+        }
+        /// Step back
+        newTrailing = leading
+      }
+    }
+    if let keyFrame = leadingIndex {
+      leadingKeyframe = keyframes[keyFrame]
+    } else {
+      leadingKeyframe = nil
+    }
+
+    if let keyFrame = trailingIndex {
+      trailingKeyframe = keyframes[keyFrame]
+    } else {
+      trailingKeyframe = nil
+    }
+  }
+}
+
+extension Array {
+
+  fileprivate func validIndex(_ index: Int) -> Int? {
+    if 0 <= index, index < endIndex {
+      return index
+    }
+    return nil
+  }
+
+}
+
+extension ContiguousArray {
+
+  fileprivate func validIndex(_ index: Int) -> Int? {
+    if 0 <= index, index < endIndex {
+      return index
+    }
+    return nil
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/NodeProperties/ValueProviders/SingleValueProvider.swift

@@ -0,0 +1,43 @@
+//
+//  SingleValueProvider.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import Foundation
+import QuartzCore
+
+/// Returns a value for every frame.
+final class SingleValueProvider<ValueType: AnyInterpolatable>: ValueProvider {
+
+  // MARK: Lifecycle
+
+  init(_ value: ValueType) {
+    self.value = value
+  }
+
+  // MARK: Internal
+
+  var value: ValueType {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var storage: ValueProviderStorage<ValueType> {
+    .singleValue(value)
+  }
+
+  var valueType: Any.Type {
+    ValueType.self
+  }
+
+  func hasUpdate(frame _: CGFloat) -> Bool {
+    hasUpdate
+  }
+
+  // MARK: Private
+
+  private var hasUpdate = true
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/ModifierNodes/TrimPathNode.swift

@@ -0,0 +1,281 @@
+//
+//  TrimPathNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/23/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - TrimPathProperties
+
+final class TrimPathProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(trim: Trim) {
+    keypathName = trim.name
+    start = NodeProperty(provider: KeyframeInterpolator(keyframes: trim.start.keyframes))
+    end = NodeProperty(provider: KeyframeInterpolator(keyframes: trim.end.keyframes))
+    offset = NodeProperty(provider: KeyframeInterpolator(keyframes: trim.offset.keyframes))
+    type = trim.trimType
+    keypathProperties = [
+      "Start" : start,
+      "End" : end,
+      "Offset" : offset,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+  let keypathName: String
+
+  let start: NodeProperty<Vector1D>
+  let end: NodeProperty<Vector1D>
+  let offset: NodeProperty<Vector1D>
+  let type: TrimType
+}
+
+// MARK: - TrimPathNode
+
+final class TrimPathNode: AnimatorNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, trim: Trim, upstreamPaths: [PathOutputNode]) {
+    outputNode = PassThroughOutputNode(parent: parentNode?.outputNode)
+    self.parentNode = parentNode
+    properties = TrimPathProperties(trim: trim)
+    self.upstreamPaths = upstreamPaths
+  }
+
+  // MARK: Internal
+
+  let properties: TrimPathProperties
+
+  let parentNode: AnimatorNode?
+  let outputNode: NodeOutput
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+  var isEnabled = true
+
+  // MARK: Animator Node
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    properties
+  }
+
+  func forceUpstreamOutputUpdates() -> Bool {
+    hasLocalUpdates || hasUpstreamUpdates
+  }
+
+  func rebuildOutputs(frame: CGFloat) {
+    /// Make sure there is a trim.
+    let startValue = properties.start.value.cgFloatValue * 0.01
+    let endValue = properties.end.value.cgFloatValue * 0.01
+    let start = min(startValue, endValue)
+    let end = max(startValue, endValue)
+
+    let offset = properties.offset.value.cgFloatValue.truncatingRemainder(dividingBy: 360) / 360
+
+    /// No need to trim, it's a full path
+    if start == 0, end == 1 {
+      return
+    }
+
+    /// All paths are empty.
+    if start == end {
+      for pathContainer in upstreamPaths {
+        pathContainer.removePaths(updateFrame: frame)
+      }
+      return
+    }
+
+    if properties.type == .simultaneously {
+      /// Just trim each path
+      for pathContainer in upstreamPaths {
+        let pathObjects = pathContainer.removePaths(updateFrame: frame)
+        for path in pathObjects {
+          // We are treating each compount path as an individual path. Its subpaths are treated as a whole.
+          pathContainer.appendPath(
+            path.trim(fromPosition: start, toPosition: end, offset: offset, trimSimultaneously: false),
+            updateFrame: frame)
+        }
+      }
+      return
+    }
+
+    /// Individual path trimming.
+
+    /// Brace yourself for the below code.
+
+    /// Normalize lengths with offset.
+    var startPosition = (start + offset).truncatingRemainder(dividingBy: 1)
+    var endPosition = (end + offset).truncatingRemainder(dividingBy: 1)
+
+    if startPosition < 0 {
+      startPosition = 1 + startPosition
+    }
+
+    if endPosition < 0 {
+      endPosition = 1 + endPosition
+    }
+    if startPosition == 1 {
+      startPosition = 0
+    }
+    if endPosition == 0 {
+      endPosition = 1
+    }
+
+    /// First get the total length of all paths.
+    var totalLength: CGFloat = 0
+    upstreamPaths.forEach({ totalLength = totalLength + $0.totalLength })
+
+    /// Now determine the start and end cut lengths
+    let startLength = startPosition * totalLength
+    let endLength = endPosition * totalLength
+    var pathStart: CGFloat = 0
+
+    /// Now loop through all path containers
+    for pathContainer in upstreamPaths {
+
+      let pathEnd = pathStart + pathContainer.totalLength
+
+      if
+        !startLength.isInRange(pathStart, pathEnd) &&
+        endLength.isInRange(pathStart, pathEnd)
+      {
+        // pathStart|=======E----------------------|pathEnd
+        // Cut path components, removing after end.
+
+        let pathCutLength = endLength - pathStart
+        let subpaths = pathContainer.removePaths(updateFrame: frame)
+        var subpathStart: CGFloat = 0
+        for path in subpaths {
+          let subpathEnd = subpathStart + path.length
+          if pathCutLength < subpathEnd {
+            /// This is the subpath that needs to be cut.
+            let cutLength = pathCutLength - subpathStart
+            let newPath = path.trim(fromPosition: 0, toPosition: cutLength / path.length, offset: 0, trimSimultaneously: false)
+            pathContainer.appendPath(newPath, updateFrame: frame)
+            break
+          } else {
+            /// Add to container and move on
+            pathContainer.appendPath(path, updateFrame: frame)
+          }
+          if pathCutLength == subpathEnd {
+            /// Right on the end. The next subpath is not included. Break.
+            break
+          }
+          subpathStart = subpathEnd
+        }
+
+      } else if
+        !endLength.isInRange(pathStart, pathEnd) &&
+        startLength.isInRange(pathStart, pathEnd)
+      {
+        // pathStart|-------S======================|pathEnd
+        //
+
+        // Cut path components, removing before beginning.
+        let pathCutLength = startLength - pathStart
+        // Clear paths from container
+        let subpaths = pathContainer.removePaths(updateFrame: frame)
+        var subpathStart: CGFloat = 0
+        for path in subpaths {
+          let subpathEnd = subpathStart + path.length
+
+          if subpathStart < pathCutLength, pathCutLength < subpathEnd {
+            /// This is the subpath that needs to be cut.
+            let cutLength = pathCutLength - subpathStart
+            let newPath = path.trim(fromPosition: cutLength / path.length, toPosition: 1, offset: 0, trimSimultaneously: false)
+            pathContainer.appendPath(newPath, updateFrame: frame)
+          } else if pathCutLength <= subpathStart {
+            pathContainer.appendPath(path, updateFrame: frame)
+          }
+          subpathStart = subpathEnd
+        }
+      } else if
+        endLength.isInRange(pathStart, pathEnd) &&
+        startLength.isInRange(pathStart, pathEnd)
+      {
+        // pathStart|-------S============E---------|endLength
+        // pathStart|=====E----------------S=======|endLength
+        // trim from path beginning to endLength.
+
+        // Cut path components, removing before beginnings.
+        let startCutLength = startLength - pathStart
+        let endCutLength = endLength - pathStart
+        // Clear paths from container
+        let subpaths = pathContainer.removePaths(updateFrame: frame)
+        var subpathStart: CGFloat = 0
+        for path in subpaths {
+
+          let subpathEnd = subpathStart + path.length
+
+          if
+            !startCutLength.isInRange(subpathStart, subpathEnd) &&
+            !endCutLength.isInRange(subpathStart, subpathEnd)
+          {
+            // The whole path is included. Add
+            // S|==============================|E
+            pathContainer.appendPath(path, updateFrame: frame)
+
+          } else if
+            startCutLength.isInRange(subpathStart, subpathEnd) &&
+            !endCutLength.isInRange(subpathStart, subpathEnd)
+          {
+            /// The start of the path needs to be trimmed
+            //  |-------S======================|E
+            let cutLength = startCutLength - subpathStart
+            let newPath = path.trim(fromPosition: cutLength / path.length, toPosition: 1, offset: 0, trimSimultaneously: false)
+            pathContainer.appendPath(newPath, updateFrame: frame)
+          } else if
+            !startCutLength.isInRange(subpathStart, subpathEnd) &&
+            endCutLength.isInRange(subpathStart, subpathEnd)
+          {
+            // S|=======E----------------------|
+            let cutLength = endCutLength - subpathStart
+            let newPath = path.trim(fromPosition: 0, toPosition: cutLength / path.length, offset: 0, trimSimultaneously: false)
+            pathContainer.appendPath(newPath, updateFrame: frame)
+            break
+          } else if
+            startCutLength.isInRange(subpathStart, subpathEnd) &&
+            endCutLength.isInRange(subpathStart, subpathEnd)
+          {
+            //  |-------S============E---------|
+            let cutFromLength = startCutLength - subpathStart
+            let cutToLength = endCutLength - subpathStart
+            let newPath = path.trim(
+              fromPosition: cutFromLength / path.length,
+              toPosition: cutToLength / path.length,
+              offset: 0,
+              trimSimultaneously: false)
+            pathContainer.appendPath(newPath, updateFrame: frame)
+            break
+          }
+
+          subpathStart = subpathEnd
+        }
+      } else if
+        (endLength <= pathStart && pathEnd <= startLength) ||
+        (startLength <= pathStart && endLength <= pathStart) ||
+        (pathEnd <= startLength && pathEnd <= endLength)
+      {
+        /// The Path needs to be cleared
+        pathContainer.removePaths(updateFrame: frame)
+      }
+
+      pathStart = pathEnd
+    }
+
+  }
+
+  // MARK: Fileprivate
+
+  fileprivate let upstreamPaths: [PathOutputNode]
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/GroupOutputNode.swift

@@ -0,0 +1,76 @@
+//
+//  TransformNodeOutput.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+import QuartzCore
+
+class GroupOutputNode: NodeOutput {
+
+  // MARK: Lifecycle
+
+  init(parent: NodeOutput?, rootNode: NodeOutput?) {
+    self.parent = parent
+    self.rootNode = rootNode
+  }
+
+  // MARK: Internal
+
+  let parent: NodeOutput?
+  let rootNode: NodeOutput?
+  var isEnabled = true
+
+  private(set) var outputPath: CGPath? = nil
+  private(set) var transform: CATransform3D = CATransform3DIdentity
+
+  func setTransform(_ xform: CATransform3D, forFrame _: CGFloat) {
+    transform = xform
+    outputPath = nil
+  }
+
+  func hasOutputUpdates(_ forFrame: CGFloat) -> Bool {
+    guard isEnabled else {
+      let upstreamUpdates = parent?.hasOutputUpdates(forFrame) ?? false
+      outputPath = parent?.outputPath
+      return upstreamUpdates
+    }
+
+    let upstreamUpdates = parent?.hasOutputUpdates(forFrame) ?? false
+    if upstreamUpdates {
+      outputPath = nil
+    }
+    let rootUpdates = rootNode?.hasOutputUpdates(forFrame) ?? false
+    if rootUpdates {
+      outputPath = nil
+    }
+
+    var localUpdates = false
+    if outputPath == nil {
+      localUpdates = true
+
+      let newPath = CGMutablePath()
+      if let parentNode = parent, let parentPath = parentNode.outputPath {
+        /// First add parent path.
+        newPath.addPath(parentPath)
+      }
+      var xform = CATransform3DGetAffineTransform(transform)
+      if
+        let rootNode = rootNode,
+        let rootPath = rootNode.outputPath,
+        let xformedPath = rootPath.copy(using: &xform)
+      {
+        /// Now add root path. Note root path is transformed.
+        newPath.addPath(xformedPath)
+      }
+
+      outputPath = newPath
+    }
+
+    return upstreamUpdates || localUpdates
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/PassThroughOutputNode.swift

@@ -0,0 +1,47 @@
+//
+//  PassThroughOutputNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+
+class PassThroughOutputNode: NodeOutput {
+
+  // MARK: Lifecycle
+
+  init(parent: NodeOutput?) {
+    self.parent = parent
+  }
+
+  // MARK: Internal
+
+  let parent: NodeOutput?
+
+  var hasUpdate = false
+  var isEnabled = true
+
+  var outputPath: CGPath? {
+    if let parent = parent {
+      return parent.outputPath
+    }
+    return nil
+  }
+
+  func hasOutputUpdates(_ forFrame: CGFloat) -> Bool {
+    /// Changes to this node do not affect downstream nodes.
+    let parentUpdate = parent?.hasOutputUpdates(forFrame) ?? false
+    /// Changes to upstream nodes do, however, affect this nodes state.
+    hasUpdate = hasUpdate || parentUpdate
+    return parentUpdate
+  }
+
+  func hasRenderUpdates(_ forFrame: CGFloat) -> Bool {
+    /// Return true if there are upstream updates or if this node has updates
+    let upstreamUpdates = parent?.hasOutputUpdates(forFrame) ?? false
+    hasUpdate = hasUpdate || upstreamUpdates
+    return hasUpdate
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/PathOutputNode.swift

@@ -0,0 +1,90 @@
+//
+//  PathNodeOutput.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+
+/// A node that has an output of a BezierPath
+class PathOutputNode: NodeOutput {
+
+  // MARK: Lifecycle
+
+  init(parent: NodeOutput?) {
+    self.parent = parent
+  }
+
+  // MARK: Internal
+
+  let parent: NodeOutput?
+
+  fileprivate(set) var outputPath: CGPath? = nil
+
+  var lastUpdateFrame: CGFloat? = nil
+  var lastPathBuildFrame: CGFloat? = nil
+  var isEnabled = true
+  fileprivate(set) var totalLength: CGFloat = 0
+  fileprivate(set) var pathObjects: [CompoundBezierPath] = []
+
+  func hasOutputUpdates(_ forFrame: CGFloat) -> Bool {
+    guard isEnabled else {
+      let upstreamUpdates = parent?.hasOutputUpdates(forFrame) ?? false
+      outputPath = parent?.outputPath
+      return upstreamUpdates
+    }
+
+    /// Ask if parent was updated
+    let upstreamUpdates = parent?.hasOutputUpdates(forFrame) ?? false
+
+    /// If parent was updated and the path hasn't been built for this frame, clear the path.
+    if upstreamUpdates && lastPathBuildFrame != forFrame {
+      outputPath = nil
+    }
+
+    if outputPath == nil {
+      /// If the path is clear, build the new path.
+      lastPathBuildFrame = forFrame
+      let newPath = CGMutablePath()
+      if let parentNode = parent, let parentPath = parentNode.outputPath {
+        newPath.addPath(parentPath)
+      }
+      for path in pathObjects {
+        for subPath in path.paths {
+          newPath.addPath(subPath.cgPath())
+        }
+      }
+      outputPath = newPath
+    }
+
+    /// Return true if there were upstream updates or if this node was updated.
+    return upstreamUpdates || (lastUpdateFrame == forFrame)
+  }
+
+  @discardableResult
+  func removePaths(updateFrame: CGFloat?) -> [CompoundBezierPath] {
+    lastUpdateFrame = updateFrame
+    let returnPaths = pathObjects
+    outputPath = nil
+    totalLength = 0
+    pathObjects = []
+    return returnPaths
+  }
+
+  func setPath(_ path: BezierPath, updateFrame: CGFloat) {
+    lastUpdateFrame = updateFrame
+    outputPath = nil
+    totalLength = path.length
+    pathObjects = [CompoundBezierPath(path: path)]
+  }
+
+  func appendPath(_ path: CompoundBezierPath, updateFrame: CGFloat) {
+    lastUpdateFrame = updateFrame
+    outputPath = nil
+    totalLength = totalLength + path.length
+    pathObjects.append(path)
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/Renderables/FillRenderer.swift

@@ -0,0 +1,71 @@
+//
+//  FillRenderer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import CoreGraphics
+import Foundation
+import QuartzCore
+
+extension FillRule {
+  var cgFillRule: CGPathFillRule {
+    switch self {
+    case .evenOdd:
+      return .evenOdd
+    default:
+      return .winding
+    }
+  }
+
+  var caFillRule: CAShapeLayerFillRule {
+    switch self {
+    case .evenOdd:
+      return CAShapeLayerFillRule.evenOdd
+    default:
+      return CAShapeLayerFillRule.nonZero
+    }
+  }
+}
+
+// MARK: - FillRenderer
+
+/// A rendered for a Path Fill
+final class FillRenderer: PassThroughOutputNode, Renderable {
+  var shouldRenderInContext = false
+
+  var color: CGColor? {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var opacity: CGFloat = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var fillRule: FillRule = .none {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  func render(_: CGContext) {
+    // do nothing
+  }
+
+  func setupSublayers(layer _: CAShapeLayer) {
+    // do nothing
+  }
+
+  func updateShapeLayer(layer: CAShapeLayer) {
+    layer.fillColor = color
+    layer.opacity = Float(opacity)
+    layer.fillRule = fillRule.caFillRule
+    hasUpdate = false
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/Renderables/GradientFillRenderer.swift

@@ -0,0 +1,242 @@
+//
+//  GradientFillRenderer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - GradientFillLayer
+
+private final class GradientFillLayer: CALayer {
+
+  var start: CGPoint = .zero {
+    didSet {
+      setNeedsDisplay()
+    }
+  }
+
+  var numberOfColors = 0 {
+    didSet {
+      setNeedsDisplay()
+    }
+  }
+
+  var colors: [CGFloat] = [] {
+    didSet {
+      setNeedsDisplay()
+    }
+  }
+
+  var end: CGPoint = .zero {
+    didSet {
+      setNeedsDisplay()
+    }
+  }
+
+  var type: GradientType = .none {
+    didSet {
+      setNeedsDisplay()
+    }
+  }
+
+  override func draw(in ctx: CGContext) {
+    var alphaColors = [CGColor]()
+    var alphaLocations = [CGFloat]()
+
+    var gradientColors = [CGColor]()
+    var colorLocations = [CGFloat]()
+    let colorSpace = CGColorSpaceCreateDeviceRGB()
+    let maskColorSpace = CGColorSpaceCreateDeviceGray()
+    for i in 0..<numberOfColors {
+      let ix = i * 4
+      if
+        colors.count > ix, let color = CGColor(
+          colorSpace: colorSpace,
+          components: [colors[ix + 1], colors[ix + 2], colors[ix + 3], 1])
+      {
+        gradientColors.append(color)
+        colorLocations.append(colors[ix])
+      }
+    }
+
+    var drawMask = false
+    for i in stride(from: numberOfColors * 4, to: colors.endIndex, by: 2) {
+      let alpha = colors[i + 1]
+      if alpha < 1 {
+        drawMask = true
+      }
+      if let color = CGColor(colorSpace: maskColorSpace, components: [alpha, 1]) {
+        alphaLocations.append(colors[i])
+        alphaColors.append(color)
+      }
+    }
+
+    /// First draw a mask is necessary.
+    if drawMask {
+      guard
+        let maskGradient = CGGradient(
+          colorsSpace: maskColorSpace,
+          colors: alphaColors as CFArray,
+          locations: alphaLocations),
+        let maskContext = CGContext(
+          data: nil,
+          width: ctx.width,
+          height: ctx.height,
+          bitsPerComponent: 8,
+          bytesPerRow: ctx.width,
+          space: maskColorSpace,
+          bitmapInfo: 0) else { return }
+      let flipVertical = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: CGFloat(maskContext.height))
+      maskContext.concatenate(flipVertical)
+      maskContext.concatenate(ctx.ctm)
+      if type == .linear {
+        maskContext.drawLinearGradient(
+          maskGradient,
+          start: start,
+          end: end,
+          options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+      } else {
+        maskContext.drawRadialGradient(
+          maskGradient,
+          startCenter: start,
+          startRadius: 0,
+          endCenter: start,
+          endRadius: start.distanceTo(end),
+          options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+      }
+      /// Clips the gradient
+      if let alphaMask = maskContext.makeImage() {
+        ctx.clip(to: ctx.boundingBoxOfClipPath, mask: alphaMask)
+      }
+    }
+
+    /// Now draw the gradient
+    guard let gradient = CGGradient(colorsSpace: colorSpace, colors: gradientColors as CFArray, locations: colorLocations)
+    else { return }
+    if type == .linear {
+      ctx.drawLinearGradient(gradient, start: start, end: end, options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+    } else {
+      ctx.drawRadialGradient(
+        gradient,
+        startCenter: start,
+        startRadius: 0,
+        endCenter: start,
+        endRadius: start.distanceTo(end),
+        options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+    }
+  }
+
+}
+
+// MARK: - GradientFillRenderer
+
+/// A rendered for a Path Fill
+final class GradientFillRenderer: PassThroughOutputNode, Renderable {
+
+  // MARK: Lifecycle
+
+  override init(parent: NodeOutput?) {
+    super.init(parent: parent)
+
+    maskLayer.fillColor = CGColor(colorSpace: CGColorSpaceCreateDeviceRGB(), components: [1, 1, 1, 1])
+    gradientLayer.mask = maskLayer
+
+    maskLayer.actions = [
+      "startPoint" : NSNull(),
+      "endPoint" : NSNull(),
+      "opacity" : NSNull(),
+      "locations" : NSNull(),
+      "colors" : NSNull(),
+      "bounds" : NSNull(),
+      "anchorPoint" : NSNull(),
+      "isRadial" : NSNull(),
+      "path" : NSNull(),
+    ]
+    gradientLayer.actions = maskLayer.actions
+  }
+
+  // MARK: Internal
+
+  var shouldRenderInContext = false
+
+  var start: CGPoint = .zero {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var numberOfColors = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var colors: [CGFloat] = [] {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var end: CGPoint = .zero {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var opacity: CGFloat = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var type: GradientType = .none {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  func render(_: CGContext) {
+    // do nothing
+  }
+
+  func setupSublayers(layer: CAShapeLayer) {
+    layer.addSublayer(gradientLayer)
+    layer.fillColor = nil
+  }
+
+  func updateShapeLayer(layer: CAShapeLayer) {
+    hasUpdate = false
+
+    guard let path = layer.path else {
+      return
+    }
+
+    let frame = path.boundingBox
+    let anchor = CGPoint(
+      x: -frame.origin.x / frame.size.width,
+      y: -frame.origin.y / frame.size.height)
+    maskLayer.path = path
+    maskLayer.bounds = path.boundingBox
+    maskLayer.anchorPoint = anchor
+
+    gradientLayer.bounds = maskLayer.bounds
+    gradientLayer.anchorPoint = anchor
+
+    // setup gradient properties
+    gradientLayer.start = start
+    gradientLayer.end = end
+    gradientLayer.numberOfColors = numberOfColors
+    gradientLayer.colors = colors
+    gradientLayer.opacity = Float(opacity)
+    gradientLayer.type = type
+  }
+
+  // MARK: Private
+
+  private let gradientLayer = GradientFillLayer()
+  private let maskLayer = CAShapeLayer()
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/Renderables/GradientStrokeRenderer.swift

@@ -0,0 +1,66 @@
+//
+//  GradientStrokeRenderer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - Renderer
+
+final class GradientStrokeRenderer: PassThroughOutputNode, Renderable {
+
+  // MARK: Lifecycle
+
+  override init(parent: NodeOutput?) {
+    strokeRender = StrokeRenderer(parent: nil)
+    gradientRender = LegacyGradientFillRenderer(parent: nil)
+    strokeRender.color = CGColor(colorSpace: CGColorSpaceCreateDeviceRGB(), components: [1, 1, 1, 1])
+    super.init(parent: parent)
+  }
+
+  // MARK: Internal
+
+  var shouldRenderInContext = true
+
+  let strokeRender: StrokeRenderer
+  let gradientRender: LegacyGradientFillRenderer
+
+  override func hasOutputUpdates(_ forFrame: CGFloat) -> Bool {
+    let updates = super.hasOutputUpdates(forFrame)
+    return updates || strokeRender.hasUpdate || gradientRender.hasUpdate
+  }
+
+  func updateShapeLayer(layer _: CAShapeLayer) {
+    /// Not Applicable
+  }
+
+  func setupSublayers(layer _: CAShapeLayer) {
+    /// Not Applicable
+  }
+
+  func render(_ inContext: CGContext) {
+    guard inContext.path != nil && inContext.path!.isEmpty == false else {
+      return
+    }
+
+    strokeRender.hasUpdate = false
+    hasUpdate = false
+    gradientRender.hasUpdate = false
+
+    strokeRender.setupForStroke(inContext)
+
+    inContext.replacePathWithStrokedPath()
+
+    /// Now draw the gradient.
+    gradientRender.render(inContext)
+
+  }
+
+  func renderBoundsFor(_ boundingBox: CGRect) -> CGRect {
+    strokeRender.renderBoundsFor(boundingBox)
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/Renderables/LegacyGradientFillRenderer.swift

@@ -0,0 +1,153 @@
+//
+//  LegacyGradientFillRenderer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import Foundation
+import QuartzCore
+
+/// A rendered for a Path Fill
+final class LegacyGradientFillRenderer: PassThroughOutputNode, Renderable {
+
+  var shouldRenderInContext = true
+
+  var start: CGPoint = .zero {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var numberOfColors = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var colors: [CGFloat] = [] {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var end: CGPoint = .zero {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var opacity: CGFloat = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var type: GradientType = .none {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  func updateShapeLayer(layer _: CAShapeLayer) {
+    // Not applicable
+  }
+
+  func setupSublayers(layer _: CAShapeLayer) {
+    // Not applicable
+  }
+
+  func render(_ inContext: CGContext) {
+    guard inContext.path != nil && inContext.path!.isEmpty == false else {
+      return
+    }
+    hasUpdate = false
+    var alphaColors = [CGColor]()
+    var alphaLocations = [CGFloat]()
+
+    var gradientColors = [CGColor]()
+    var colorLocations = [CGFloat]()
+    let colorSpace = CGColorSpaceCreateDeviceRGB()
+    let maskColorSpace = CGColorSpaceCreateDeviceGray()
+    for i in 0..<numberOfColors {
+      let ix = i * 4
+      if
+        colors.count > ix, let color = CGColor(
+          colorSpace: colorSpace,
+          components: [colors[ix + 1], colors[ix + 2], colors[ix + 3], 1])
+      {
+        gradientColors.append(color)
+        colorLocations.append(colors[ix])
+      }
+    }
+
+    var drawMask = false
+    for i in stride(from: numberOfColors * 4, to: colors.endIndex, by: 2) {
+      let alpha = colors[i + 1]
+      if alpha < 1 {
+        drawMask = true
+      }
+      if let color = CGColor(colorSpace: maskColorSpace, components: [alpha, 1]) {
+        alphaLocations.append(colors[i])
+        alphaColors.append(color)
+      }
+    }
+
+    inContext.setAlpha(opacity)
+    inContext.clip()
+
+    /// First draw a mask is necessary.
+    if drawMask {
+      guard
+        let maskGradient = CGGradient(
+          colorsSpace: maskColorSpace,
+          colors: alphaColors as CFArray,
+          locations: alphaLocations),
+        let maskContext = CGContext(
+          data: nil,
+          width: inContext.width,
+          height: inContext.height,
+          bitsPerComponent: 8,
+          bytesPerRow: inContext.width,
+          space: maskColorSpace,
+          bitmapInfo: 0) else { return }
+      let flipVertical = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: CGFloat(maskContext.height))
+      maskContext.concatenate(flipVertical)
+      maskContext.concatenate(inContext.ctm)
+      if type == .linear {
+        maskContext.drawLinearGradient(
+          maskGradient,
+          start: start,
+          end: end,
+          options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+      } else {
+        maskContext.drawRadialGradient(
+          maskGradient,
+          startCenter: start,
+          startRadius: 0,
+          endCenter: start,
+          endRadius: start.distanceTo(end),
+          options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+      }
+      /// Clips the gradient
+      if let alphaMask = maskContext.makeImage() {
+        inContext.clip(to: inContext.boundingBoxOfClipPath, mask: alphaMask)
+      }
+    }
+
+    /// Now draw the gradient
+    guard let gradient = CGGradient(colorsSpace: colorSpace, colors: gradientColors as CFArray, locations: colorLocations)
+    else { return }
+    if type == .linear {
+      inContext.drawLinearGradient(gradient, start: start, end: end, options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+    } else {
+      inContext.drawRadialGradient(
+        gradient,
+        startCenter: start,
+        startRadius: 0,
+        endCenter: start,
+        endRadius: start.distanceTo(end),
+        options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+    }
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/OutputNodes/Renderables/StrokeRenderer.swift

@@ -0,0 +1,166 @@
+//
+//  StrokeRenderer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import Foundation
+import QuartzCore
+
+extension LineJoin {
+  var cgLineJoin: CGLineJoin {
+    switch self {
+    case .bevel:
+      return .bevel
+    case .none:
+      return .miter
+    case .miter:
+      return .miter
+    case .round:
+      return .round
+    }
+  }
+
+  var caLineJoin: CAShapeLayerLineJoin {
+    switch self {
+    case .none:
+      return CAShapeLayerLineJoin.miter
+    case .miter:
+      return CAShapeLayerLineJoin.miter
+    case .round:
+      return CAShapeLayerLineJoin.round
+    case .bevel:
+      return CAShapeLayerLineJoin.bevel
+    }
+  }
+}
+
+extension LineCap {
+  var cgLineCap: CGLineCap {
+    switch self {
+    case .none:
+      return .butt
+    case .butt:
+      return .butt
+    case .round:
+      return .round
+    case .square:
+      return .square
+    }
+  }
+
+  var caLineCap: CAShapeLayerLineCap {
+    switch self {
+    case .none:
+      return CAShapeLayerLineCap.butt
+    case .butt:
+      return CAShapeLayerLineCap.butt
+    case .round:
+      return CAShapeLayerLineCap.round
+    case .square:
+      return CAShapeLayerLineCap.square
+    }
+  }
+}
+
+// MARK: - StrokeRenderer
+
+/// A rendered that renders a stroke on a path.
+final class StrokeRenderer: PassThroughOutputNode, Renderable {
+
+  var shouldRenderInContext = false
+
+  var color: CGColor? {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var opacity: CGFloat = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var width: CGFloat = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var miterLimit: CGFloat = 0 {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var lineCap: LineCap = .none {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var lineJoin: LineJoin = .none {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var dashPhase: CGFloat? {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  var dashLengths: [CGFloat]? {
+    didSet {
+      hasUpdate = true
+    }
+  }
+
+  func setupSublayers(layer _: CAShapeLayer) {
+    // empty
+  }
+
+  func renderBoundsFor(_ boundingBox: CGRect) -> CGRect {
+    boundingBox.insetBy(dx: -width, dy: -width)
+  }
+
+  func setupForStroke(_ inContext: CGContext) {
+    inContext.setLineWidth(width)
+    inContext.setMiterLimit(miterLimit)
+    inContext.setLineCap(lineCap.cgLineCap)
+    inContext.setLineJoin(lineJoin.cgLineJoin)
+    if let dashPhase = dashPhase, let lengths = dashLengths {
+      inContext.setLineDash(phase: dashPhase, lengths: lengths)
+    } else {
+      inContext.setLineDash(phase: 0, lengths: [])
+    }
+  }
+
+  func render(_ inContext: CGContext) {
+    guard inContext.path != nil && inContext.path!.isEmpty == false else {
+      return
+    }
+    guard let color = color else { return }
+    hasUpdate = false
+    setupForStroke(inContext)
+    inContext.setAlpha(opacity)
+    inContext.setStrokeColor(color)
+    inContext.strokePath()
+  }
+
+  func updateShapeLayer(layer: CAShapeLayer) {
+    layer.strokeColor = color
+    layer.opacity = Float(opacity)
+    layer.lineWidth = width
+    layer.lineJoin = lineJoin.caLineJoin
+    layer.lineCap = lineCap.caLineCap
+    layer.lineDashPhase = dashPhase ?? 0
+    layer.fillColor = nil
+    if let dashPattern = dashLengths {
+      layer.lineDashPattern = dashPattern.map({ NSNumber(value: Double($0)) })
+    }
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/PathNodes/EllipseNode.swift

@@ -0,0 +1,139 @@
+//
+//  EllipseNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/17/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - EllipseNodeProperties
+
+final class EllipseNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(ellipse: Ellipse) {
+    keypathName = ellipse.name
+    direction = ellipse.direction
+    position = NodeProperty(provider: KeyframeInterpolator(keyframes: ellipse.position.keyframes))
+    size = NodeProperty(provider: KeyframeInterpolator(keyframes: ellipse.size.keyframes))
+    keypathProperties = [
+      "Position" : position,
+      "Size" : size,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  let direction: PathDirection
+  let position: NodeProperty<Vector3D>
+  let size: NodeProperty<Vector3D>
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+}
+
+// MARK: - EllipseNode
+
+final class EllipseNode: AnimatorNode, PathNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, ellipse: Ellipse) {
+    pathOutput = PathOutputNode(parent: parentNode?.outputNode)
+    properties = EllipseNodeProperties(ellipse: ellipse)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  static let ControlPointConstant: CGFloat = 0.55228
+
+  let pathOutput: PathOutputNode
+
+  let properties: EllipseNodeProperties
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  // MARK: Animator Node
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    properties
+  }
+
+  var isEnabled = true {
+    didSet {
+      pathOutput.isEnabled = isEnabled
+    }
+  }
+
+  func rebuildOutputs(frame: CGFloat) {
+    pathOutput.setPath(
+      .ellipse(
+        size: properties.size.value.sizeValue,
+        center: properties.position.value.pointValue,
+        direction: properties.direction),
+      updateFrame: frame)
+  }
+
+}
+
+extension BezierPath {
+  /// Constructs a `BezierPath` in the shape of an ellipse
+  static func ellipse(
+    size: CGSize,
+    center: CGPoint,
+    direction: PathDirection)
+    -> BezierPath
+  {
+    // Unfortunately we HAVE to manually build out the ellipse.
+    // Every Apple method constructs an ellipse from the 3 o-clock position
+    // After effects constructs from the Noon position.
+    // After effects does clockwise, but also has a flag for reversed.
+    var half = size * 0.5
+    if direction == .counterClockwise {
+      half.width = half.width * -1
+    }
+
+    let q1 = CGPoint(x: center.x, y: center.y - half.height)
+    let q2 = CGPoint(x: center.x + half.width, y: center.y)
+    let q3 = CGPoint(x: center.x, y: center.y + half.height)
+    let q4 = CGPoint(x: center.x - half.width, y: center.y)
+
+    let cp = half * EllipseNode.ControlPointConstant
+
+    var path = BezierPath(startPoint: CurveVertex(
+      point: q1,
+      inTangentRelative: CGPoint(x: -cp.width, y: 0),
+      outTangentRelative: CGPoint(x: cp.width, y: 0)))
+    path.addVertex(CurveVertex(
+      point: q2,
+      inTangentRelative: CGPoint(x: 0, y: -cp.height),
+      outTangentRelative: CGPoint(x: 0, y: cp.height)))
+
+    path.addVertex(CurveVertex(
+      point: q3,
+      inTangentRelative: CGPoint(x: cp.width, y: 0),
+      outTangentRelative: CGPoint(x: -cp.width, y: 0)))
+
+    path.addVertex(CurveVertex(
+      point: q4,
+      inTangentRelative: CGPoint(x: 0, y: cp.height),
+      outTangentRelative: CGPoint(x: 0, y: -cp.height)))
+
+    path.addVertex(CurveVertex(
+      point: q1,
+      inTangentRelative: CGPoint(x: -cp.width, y: 0),
+      outTangentRelative: CGPoint(x: cp.width, y: 0)))
+    path.close()
+    return path
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/PathNodes/PolygonNode.swift

@@ -0,0 +1,170 @@
+//
+//  PolygonNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/21/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - PolygonNodeProperties
+
+final class PolygonNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(star: Star) {
+    keypathName = star.name
+    direction = star.direction
+    position = NodeProperty(provider: KeyframeInterpolator(keyframes: star.position.keyframes))
+    outerRadius = NodeProperty(provider: KeyframeInterpolator(keyframes: star.outerRadius.keyframes))
+    outerRoundedness = NodeProperty(provider: KeyframeInterpolator(keyframes: star.outerRoundness.keyframes))
+    rotation = NodeProperty(provider: KeyframeInterpolator(keyframes: star.rotation.keyframes))
+    points = NodeProperty(provider: KeyframeInterpolator(keyframes: star.points.keyframes))
+    keypathProperties = [
+      "Position" : position,
+      "Outer Radius" : outerRadius,
+      "Outer Roundedness" : outerRoundedness,
+      "Rotation" : rotation,
+      "Points" : points,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  var childKeypaths: [KeypathSearchable] = []
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+  let direction: PathDirection
+  let position: NodeProperty<Vector3D>
+  let outerRadius: NodeProperty<Vector1D>
+  let outerRoundedness: NodeProperty<Vector1D>
+  let rotation: NodeProperty<Vector1D>
+  let points: NodeProperty<Vector1D>
+}
+
+// MARK: - PolygonNode
+
+final class PolygonNode: AnimatorNode, PathNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, star: Star) {
+    pathOutput = PathOutputNode(parent: parentNode?.outputNode)
+    properties = PolygonNodeProperties(star: star)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  /// Magic number needed for constructing path.
+  static let PolygonConstant: CGFloat = 0.25
+
+  let properties: PolygonNodeProperties
+
+  let pathOutput: PathOutputNode
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  // MARK: Animator Node
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    properties
+  }
+
+  var isEnabled = true {
+    didSet {
+      pathOutput.isEnabled = isEnabled
+    }
+  }
+
+  func rebuildOutputs(frame: CGFloat) {
+    let path = BezierPath.polygon(
+      position: properties.position.value.pointValue,
+      numberOfPoints: properties.points.value.cgFloatValue,
+      outerRadius: properties.outerRadius.value.cgFloatValue,
+      outerRoundedness: properties.outerRoundedness.value.cgFloatValue,
+      rotation: properties.rotation.value.cgFloatValue,
+      direction: properties.direction)
+
+    pathOutput.setPath(path, updateFrame: frame)
+  }
+
+}
+
+extension BezierPath {
+  /// Creates a `BezierPath` in the shape of a polygon
+  static func polygon(
+    position: CGPoint,
+    numberOfPoints: CGFloat,
+    outerRadius: CGFloat,
+    outerRoundedness inputOuterRoundedness: CGFloat,
+    rotation: CGFloat,
+    direction: PathDirection)
+    -> BezierPath
+  {
+    var currentAngle = (rotation - 90).toRadians()
+    let anglePerPoint = ((2 * CGFloat.pi) / numberOfPoints)
+    let outerRoundedness = inputOuterRoundedness * 0.01
+
+    var point = CGPoint(
+      x: outerRadius * cos(currentAngle),
+      y: outerRadius * sin(currentAngle))
+    var vertices = [CurveVertex(point: point + position, inTangentRelative: .zero, outTangentRelative: .zero)]
+
+    var previousPoint = point
+    currentAngle += anglePerPoint;
+    for _ in 0..<Int(ceil(numberOfPoints)) {
+      previousPoint = point
+      point = CGPoint(
+        x: outerRadius * cos(currentAngle),
+        y: outerRadius * sin(currentAngle))
+
+      if outerRoundedness != 0 {
+        let cp1Theta = (atan2(previousPoint.y, previousPoint.x) - CGFloat.pi / 2)
+        let cp1Dx = cos(cp1Theta);
+        let cp1Dy = sin(cp1Theta);
+
+        let cp2Theta = (atan2(point.y, point.x) - CGFloat.pi / 2)
+        let cp2Dx = cos(cp2Theta)
+        let cp2Dy = sin(cp2Theta)
+
+        let cp1 = CGPoint(
+          x: outerRadius * outerRoundedness * PolygonNode.PolygonConstant * cp1Dx,
+          y: outerRadius * outerRoundedness * PolygonNode.PolygonConstant * cp1Dy)
+        let cp2 = CGPoint(
+          x: outerRadius * outerRoundedness * PolygonNode.PolygonConstant * cp2Dx,
+          y: outerRadius * outerRoundedness * PolygonNode.PolygonConstant * cp2Dy)
+
+        let previousVertex = vertices[vertices.endIndex - 1]
+        vertices[vertices.endIndex - 1] = CurveVertex(
+          previousVertex.inTangent,
+          previousVertex.point,
+          previousVertex.point - cp1)
+        vertices.append(CurveVertex(point: point + position, inTangentRelative: cp2, outTangentRelative: .zero))
+      } else {
+        vertices.append(CurveVertex(point: point + position, inTangentRelative: .zero, outTangentRelative: .zero))
+      }
+      currentAngle += anglePerPoint;
+    }
+    let reverse = direction == .counterClockwise
+    if reverse {
+      vertices = vertices.reversed()
+    }
+    var path = BezierPath()
+    for vertex in vertices {
+      path.addVertex(reverse ? vertex.reversed() : vertex)
+    }
+    path.close()
+    return path
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/PathNodes/RectNode.swift

@@ -0,0 +1,225 @@
+//
+//  RectNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/21/19.
+//
+
+import CoreGraphics
+import Foundation
+
+// MARK: - RectNodeProperties
+
+final class RectNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(rectangle: Rectangle) {
+    keypathName = rectangle.name
+    direction = rectangle.direction
+    position = NodeProperty(provider: KeyframeInterpolator(keyframes: rectangle.position.keyframes))
+    size = NodeProperty(provider: KeyframeInterpolator(keyframes: rectangle.size.keyframes))
+    cornerRadius = NodeProperty(provider: KeyframeInterpolator(keyframes: rectangle.cornerRadius.keyframes))
+
+    keypathProperties = [
+      "Position" : position,
+      "Size" : size,
+      "Roundness" : cornerRadius,
+    ]
+
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+  let direction: PathDirection
+  let position: NodeProperty<Vector3D>
+  let size: NodeProperty<Vector3D>
+  let cornerRadius: NodeProperty<Vector1D>
+
+}
+
+// MARK: - RectangleNode
+
+final class RectangleNode: AnimatorNode, PathNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, rectangle: Rectangle) {
+    properties = RectNodeProperties(rectangle: rectangle)
+    pathOutput = PathOutputNode(parent: parentNode?.outputNode)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  let properties: RectNodeProperties
+
+  let pathOutput: PathOutputNode
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  // MARK: Animator Node
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    properties
+  }
+
+  var isEnabled = true {
+    didSet {
+      pathOutput.isEnabled = isEnabled
+    }
+  }
+
+  func rebuildOutputs(frame: CGFloat) {
+    pathOutput.setPath(
+      .rectangle(
+        position: properties.position.value.pointValue,
+        size: properties.size.value.sizeValue,
+        cornerRadius: properties.cornerRadius.value.cgFloatValue,
+        direction: properties.direction),
+      updateFrame: frame)
+  }
+
+}
+
+// MARK: - BezierPath + rectangle
+
+extension BezierPath {
+  /// Constructs a `BezierPath` in the shape of a rectangle, optionally with rounded corners
+  static func rectangle(
+    position: CGPoint,
+    size inputSize: CGSize,
+    cornerRadius: CGFloat,
+    direction: PathDirection)
+    -> BezierPath
+  {
+    let size = inputSize * 0.5
+    let radius = min(min(cornerRadius, size.width) , size.height)
+
+    var bezierPath = BezierPath()
+    let points: [CurveVertex]
+
+    if radius <= 0 {
+      /// No Corners
+      points = [
+        /// Lead In
+        CurveVertex(
+          point: CGPoint(x: size.width, y: -size.height),
+          inTangentRelative: .zero,
+          outTangentRelative: .zero)
+          .translated(position),
+        /// Corner 1
+        CurveVertex(
+          point: CGPoint(x: size.width, y: size.height),
+          inTangentRelative: .zero,
+          outTangentRelative: .zero)
+          .translated(position),
+        /// Corner 2
+        CurveVertex(
+          point: CGPoint(x: -size.width, y: size.height),
+          inTangentRelative: .zero,
+          outTangentRelative: .zero)
+          .translated(position),
+        /// Corner 3
+        CurveVertex(
+          point: CGPoint(x: -size.width, y: -size.height),
+          inTangentRelative: .zero,
+          outTangentRelative: .zero)
+          .translated(position),
+        /// Corner 4
+        CurveVertex(
+          point: CGPoint(x: size.width, y: -size.height),
+          inTangentRelative: .zero,
+          outTangentRelative: .zero)
+          .translated(position),
+      ]
+    } else {
+      let controlPoint = radius * EllipseNode.ControlPointConstant
+      points = [
+        /// Lead In
+        CurveVertex(
+          CGPoint(x: radius, y: 0),
+          CGPoint(x: radius, y: 0),
+          CGPoint(x: radius, y: 0))
+          .translated(CGPoint(x: -radius, y: radius))
+          .translated(CGPoint(x: size.width, y: -size.height))
+          .translated(position),
+        /// Corner 1
+        CurveVertex(
+          CGPoint(x: radius, y: 0), // In tangent
+          CGPoint(x: radius, y: 0), // Point
+          CGPoint(x: radius, y: controlPoint))
+          .translated(CGPoint(x: -radius, y: -radius))
+          .translated(CGPoint(x: size.width, y: size.height))
+          .translated(position),
+        CurveVertex(
+          CGPoint(x: controlPoint, y: radius), // In tangent
+          CGPoint(x: 0, y: radius), // Point
+          CGPoint(x: 0, y: radius)) // Out Tangent
+          .translated(CGPoint(x: -radius, y: -radius))
+          .translated(CGPoint(x: size.width, y: size.height))
+          .translated(position),
+        /// Corner 2
+        CurveVertex(
+          CGPoint(x: 0, y: radius), // In tangent
+          CGPoint(x: 0, y: radius), // Point
+          CGPoint(x: -controlPoint, y: radius))// Out tangent
+          .translated(CGPoint(x: radius, y: -radius))
+          .translated(CGPoint(x: -size.width, y: size.height))
+          .translated(position),
+        CurveVertex(
+          CGPoint(x: -radius, y: controlPoint), // In tangent
+          CGPoint(x: -radius, y: 0), // Point
+          CGPoint(x: -radius, y: 0)) // Out tangent
+          .translated(CGPoint(x: radius, y: -radius))
+          .translated(CGPoint(x: -size.width, y: size.height))
+          .translated(position),
+        /// Corner 3
+        CurveVertex(
+          CGPoint(x: -radius, y: 0), // In tangent
+          CGPoint(x: -radius, y: 0), // Point
+          CGPoint(x: -radius, y: -controlPoint)) // Out tangent
+          .translated(CGPoint(x: radius, y: radius))
+          .translated(CGPoint(x: -size.width, y: -size.height))
+          .translated(position),
+        CurveVertex(
+          CGPoint(x: -controlPoint, y: -radius), // In tangent
+          CGPoint(x: 0, y: -radius), // Point
+          CGPoint(x: 0, y: -radius)) // Out tangent
+          .translated(CGPoint(x: radius, y: radius))
+          .translated(CGPoint(x: -size.width, y: -size.height))
+          .translated(position),
+        /// Corner 4
+        CurveVertex(
+          CGPoint(x: 0, y: -radius), // In tangent
+          CGPoint(x: 0, y: -radius), // Point
+          CGPoint(x: controlPoint, y: -radius)) // Out tangent
+          .translated(CGPoint(x: -radius, y: radius))
+          .translated(CGPoint(x: size.width, y: -size.height))
+          .translated(position),
+        CurveVertex(
+          CGPoint(x: radius, y: -controlPoint), // In tangent
+          CGPoint(x: radius, y: 0), // Point
+          CGPoint(x: radius, y: 0)) // Out tangent
+          .translated(CGPoint(x: -radius, y: radius))
+          .translated(CGPoint(x: size.width, y: -size.height))
+          .translated(position),
+      ]
+    }
+    let reversed = direction == .counterClockwise
+    let pathPoints = reversed ? points.reversed() : points
+    for point in pathPoints {
+      bezierPath.addVertex(reversed ? point.reversed() : point)
+    }
+    bezierPath.close()
+    return bezierPath
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/PathNodes/ShapeNode.swift

@@ -0,0 +1,74 @@
+//
+//  PathNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/16/19.
+//
+
+import CoreGraphics
+import Foundation
+
+// MARK: - ShapeNodeProperties
+
+final class ShapeNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(shape: Shape) {
+    keypathName = shape.name
+    path = NodeProperty(provider: KeyframeInterpolator(keyframes: shape.path.keyframes))
+    keypathProperties = [
+      "Path" : path,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  let path: NodeProperty<BezierPath>
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+}
+
+// MARK: - ShapeNode
+
+final class ShapeNode: AnimatorNode, PathNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, shape: Shape) {
+    pathOutput = PathOutputNode(parent: parentNode?.outputNode)
+    properties = ShapeNodeProperties(shape: shape)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  let properties: ShapeNodeProperties
+
+  let pathOutput: PathOutputNode
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  // MARK: Animator Node
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    properties
+  }
+
+  var isEnabled = true {
+    didSet {
+      pathOutput.isEnabled = isEnabled
+    }
+  }
+
+  func rebuildOutputs(frame: CGFloat) {
+    pathOutput.setPath(properties.path.value, updateFrame: frame)
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/PathNodes/StarNode.swift

@@ -0,0 +1,222 @@
+//
+//  StarNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/21/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - StarNodeProperties
+
+final class StarNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(star: Star) {
+    keypathName = star.name
+    direction = star.direction
+    position = NodeProperty(provider: KeyframeInterpolator(keyframes: star.position.keyframes))
+    outerRadius = NodeProperty(provider: KeyframeInterpolator(keyframes: star.outerRadius.keyframes))
+    outerRoundedness = NodeProperty(provider: KeyframeInterpolator(keyframes: star.outerRoundness.keyframes))
+    if let innerRadiusKeyframes = star.innerRadius?.keyframes {
+      innerRadius = NodeProperty(provider: KeyframeInterpolator(keyframes: innerRadiusKeyframes))
+    } else {
+      innerRadius = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+    }
+    if let innderRoundedness = star.innerRoundness?.keyframes {
+      innerRoundedness = NodeProperty(provider: KeyframeInterpolator(keyframes: innderRoundedness))
+    } else {
+      innerRoundedness = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+    }
+    rotation = NodeProperty(provider: KeyframeInterpolator(keyframes: star.rotation.keyframes))
+    points = NodeProperty(provider: KeyframeInterpolator(keyframes: star.points.keyframes))
+    keypathProperties = [
+      "Position" : position,
+      "Outer Radius" : outerRadius,
+      "Outer Roundedness" : outerRoundedness,
+      "Inner Radius" : innerRadius,
+      "Inner Roundedness" : innerRoundedness,
+      "Rotation" : rotation,
+      "Points" : points,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+  let direction: PathDirection
+  let position: NodeProperty<Vector3D>
+  let outerRadius: NodeProperty<Vector1D>
+  let outerRoundedness: NodeProperty<Vector1D>
+  let innerRadius: NodeProperty<Vector1D>
+  let innerRoundedness: NodeProperty<Vector1D>
+  let rotation: NodeProperty<Vector1D>
+  let points: NodeProperty<Vector1D>
+}
+
+// MARK: - StarNode
+
+final class StarNode: AnimatorNode, PathNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, star: Star) {
+    pathOutput = PathOutputNode(parent: parentNode?.outputNode)
+    properties = StarNodeProperties(star: star)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  /// Magic number needed for building path data
+  static let PolystarConstant: CGFloat = 0.47829
+
+  let properties: StarNodeProperties
+
+  let pathOutput: PathOutputNode
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  // MARK: Animator Node
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    properties
+  }
+
+  var isEnabled = true {
+    didSet {
+      pathOutput.isEnabled = isEnabled
+    }
+  }
+
+  func rebuildOutputs(frame: CGFloat) {
+    let path = BezierPath.star(
+      position: properties.position.value.pointValue,
+      outerRadius: properties.outerRadius.value.cgFloatValue,
+      innerRadius: properties.innerRadius.value.cgFloatValue,
+      outerRoundedness: properties.outerRoundedness.value.cgFloatValue,
+      innerRoundedness: properties.innerRoundedness.value.cgFloatValue,
+      numberOfPoints: properties.points.value.cgFloatValue,
+      rotation: properties.rotation.value.cgFloatValue,
+      direction: properties.direction)
+
+    pathOutput.setPath(path, updateFrame: frame)
+  }
+
+}
+
+extension BezierPath {
+  /// Constructs a `BezierPath` in the shape of a star
+  static func star(
+    position: CGPoint,
+    outerRadius: CGFloat,
+    innerRadius: CGFloat,
+    outerRoundedness inoutOuterRoundedness: CGFloat,
+    innerRoundedness inputInnerRoundedness: CGFloat,
+    numberOfPoints: CGFloat,
+    rotation: CGFloat,
+    direction: PathDirection)
+    -> BezierPath
+  {
+    var currentAngle = (rotation - 90).toRadians()
+    let anglePerPoint = (2 * CGFloat.pi) / numberOfPoints
+    let halfAnglePerPoint = anglePerPoint / 2.0
+    let partialPointAmount = numberOfPoints - floor(numberOfPoints)
+    let outerRoundedness = inoutOuterRoundedness * 0.01
+    let innerRoundedness = inputInnerRoundedness * 0.01
+
+    var point: CGPoint = .zero
+
+    var partialPointRadius: CGFloat = 0
+    if partialPointAmount != 0 {
+      currentAngle += halfAnglePerPoint * (1 - partialPointAmount)
+      partialPointRadius = innerRadius + partialPointAmount * (outerRadius - innerRadius)
+      point.x = (partialPointRadius * cos(currentAngle))
+      point.y = (partialPointRadius * sin(currentAngle))
+      currentAngle += anglePerPoint * partialPointAmount / 2
+    } else {
+      point.x = (outerRadius * cos(currentAngle))
+      point.y = (outerRadius * sin(currentAngle))
+      currentAngle += halfAnglePerPoint
+    }
+
+    var vertices = [CurveVertex]()
+    vertices.append(CurveVertex(point: point + position, inTangentRelative: .zero, outTangentRelative: .zero))
+
+    var previousPoint = point
+    var longSegment = false
+    let numPoints = Int(ceil(numberOfPoints) * 2)
+    for i in 0..<numPoints {
+      var radius = longSegment ? outerRadius : innerRadius
+      var dTheta = halfAnglePerPoint
+      if partialPointRadius != 0 && i == numPoints - 2 {
+        dTheta = anglePerPoint * partialPointAmount / 2
+      }
+      if partialPointRadius != 0 && i == numPoints - 1 {
+        radius = partialPointRadius
+      }
+      previousPoint = point
+      point.x = (radius * cos(currentAngle))
+      point.y = (radius * sin(currentAngle))
+
+      if innerRoundedness == 0 && outerRoundedness == 0 {
+        vertices.append(CurveVertex(point: point + position, inTangentRelative: .zero, outTangentRelative: .zero))
+      } else {
+        let cp1Theta = (atan2(previousPoint.y, previousPoint.x) - CGFloat.pi / 2)
+        let cp1Dx = cos(cp1Theta)
+        let cp1Dy = sin(cp1Theta)
+
+        let cp2Theta = (atan2(point.y, point.x) - CGFloat.pi / 2)
+        let cp2Dx = cos(cp2Theta)
+        let cp2Dy = sin(cp2Theta)
+
+        let cp1Roundedness = longSegment ? innerRoundedness : outerRoundedness
+        let cp2Roundedness = longSegment ? outerRoundedness : innerRoundedness
+        let cp1Radius = longSegment ? innerRadius : outerRadius
+        let cp2Radius = longSegment ? outerRadius : innerRadius
+
+        var cp1 = CGPoint(
+          x: cp1Radius * cp1Roundedness * StarNode.PolystarConstant * cp1Dx,
+          y: cp1Radius * cp1Roundedness * StarNode.PolystarConstant * cp1Dy)
+        var cp2 = CGPoint(
+          x: cp2Radius * cp2Roundedness * StarNode.PolystarConstant * cp2Dx,
+          y: cp2Radius * cp2Roundedness * StarNode.PolystarConstant * cp2Dy)
+        if partialPointAmount != 0 {
+          if i == 0 {
+            cp1 = cp1 * partialPointAmount
+          } else if i == numPoints - 1 {
+            cp2 = cp2 * partialPointAmount
+          }
+        }
+        let previousVertex = vertices[vertices.endIndex - 1]
+        vertices[vertices.endIndex - 1] = CurveVertex(
+          previousVertex.inTangent,
+          previousVertex.point,
+          previousVertex.point - cp1)
+        vertices.append(CurveVertex(point: point + position, inTangentRelative: cp2, outTangentRelative: .zero))
+      }
+      currentAngle += dTheta
+      longSegment = !longSegment
+    }
+
+    let reverse = direction == .counterClockwise
+    if reverse {
+      vertices = vertices.reversed()
+    }
+    var path = BezierPath()
+    for vertex in vertices {
+      path.addVertex(reverse ? vertex.reversed() : vertex)
+    }
+    path.close()
+    return path
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/RenderContainers/GroupNode.swift

@@ -0,0 +1,155 @@
+//
+//  GroupNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/18/19.
+//
+
+import CoreGraphics
+import Foundation
+import QuartzCore
+
+// MARK: - GroupNodeProperties
+
+final class GroupNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(transform: ShapeTransform?) {
+    if let transform = transform {
+      anchor = NodeProperty(provider: KeyframeInterpolator(keyframes: transform.anchor.keyframes))
+      position = NodeProperty(provider: KeyframeInterpolator(keyframes: transform.position.keyframes))
+      scale = NodeProperty(provider: KeyframeInterpolator(keyframes: transform.scale.keyframes))
+      rotation = NodeProperty(provider: KeyframeInterpolator(keyframes: transform.rotation.keyframes))
+      opacity = NodeProperty(provider: KeyframeInterpolator(keyframes: transform.opacity.keyframes))
+      skew = NodeProperty(provider: KeyframeInterpolator(keyframes: transform.skew.keyframes))
+      skewAxis = NodeProperty(provider: KeyframeInterpolator(keyframes: transform.skewAxis.keyframes))
+    } else {
+      /// Transform node missing. Default to empty transform.
+      anchor = NodeProperty(provider: SingleValueProvider(Vector3D(x: CGFloat(0), y: CGFloat(0), z: CGFloat(0))))
+      position = NodeProperty(provider: SingleValueProvider(Vector3D(x: CGFloat(0), y: CGFloat(0), z: CGFloat(0))))
+      scale = NodeProperty(provider: SingleValueProvider(Vector3D(x: CGFloat(100), y: CGFloat(100), z: CGFloat(100))))
+      rotation = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+      opacity = NodeProperty(provider: SingleValueProvider(Vector1D(100)))
+      skew = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+      skewAxis = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+    }
+    keypathProperties = [
+      "Anchor Point" : anchor,
+      "Position" : position,
+      "Scale" : scale,
+      "Rotation" : rotation,
+      "Opacity" : opacity,
+      "Skew" : skew,
+      "Skew Axis" : skewAxis,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName = "Transform"
+
+  var childKeypaths: [KeypathSearchable] = []
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+  let anchor: NodeProperty<Vector3D>
+  let position: NodeProperty<Vector3D>
+  let scale: NodeProperty<Vector3D>
+  let rotation: NodeProperty<Vector1D>
+  let opacity: NodeProperty<Vector1D>
+  let skew: NodeProperty<Vector1D>
+  let skewAxis: NodeProperty<Vector1D>
+
+  var caTransform: CATransform3D {
+    CATransform3D.makeTransform(
+      anchor: anchor.value.pointValue,
+      position: position.value.pointValue,
+      scale: scale.value.sizeValue,
+      rotation: rotation.value.cgFloatValue,
+      skew: skew.value.cgFloatValue,
+      skewAxis: skewAxis.value.cgFloatValue)
+  }
+}
+
+// MARK: - GroupNode
+
+final class GroupNode: AnimatorNode {
+
+  // MARK: Lifecycle
+
+  // MARK: Initializer
+  init(name: String, parentNode: AnimatorNode?, tree: NodeTree) {
+    self.parentNode = parentNode
+    keypathName = name
+    rootNode = tree.rootNode
+    properties = GroupNodeProperties(transform: tree.transform)
+    groupOutput = GroupOutputNode(parent: parentNode?.outputNode, rootNode: rootNode?.outputNode)
+    var childKeypaths: [KeypathSearchable] = tree.childrenNodes
+    childKeypaths.append(properties)
+    self.childKeypaths = childKeypaths
+
+    for childContainer in tree.renderContainers {
+      container.insertRenderLayer(childContainer)
+    }
+  }
+
+  // MARK: Internal
+
+  // MARK: Properties
+  let groupOutput: GroupOutputNode
+
+  let properties: GroupNodeProperties
+
+  let rootNode: AnimatorNode?
+
+  var container = ShapeContainerLayer()
+
+  // MARK: Keypath Searchable
+
+  let keypathName: String
+
+  let childKeypaths: [KeypathSearchable]
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  var keypathLayer: CALayer? {
+    container
+  }
+
+  // MARK: Animator Node Protocol
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    properties
+  }
+
+  var outputNode: NodeOutput {
+    groupOutput
+  }
+
+  var isEnabled = true {
+    didSet {
+      container.isHidden = !isEnabled
+    }
+  }
+
+  func performAdditionalLocalUpdates(frame: CGFloat, forceLocalUpdate: Bool) -> Bool {
+    rootNode?.updateContents(frame, forceLocalUpdate: forceLocalUpdate) ?? false
+  }
+
+  func performAdditionalOutputUpdates(_ frame: CGFloat, forceOutputUpdate: Bool) {
+    rootNode?.updateOutputs(frame, forceOutputUpdate: forceOutputUpdate)
+  }
+
+  func rebuildOutputs(frame: CGFloat) {
+    container.opacity = Float(properties.opacity.value.cgFloatValue) * 0.01
+    container.transform = properties.caTransform
+    groupOutput.setTransform(container.transform, forFrame: frame)
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/RenderNodes/FillNode.swift

@@ -0,0 +1,90 @@
+//
+//  FillNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/17/19.
+//
+
+import CoreGraphics
+import Foundation
+
+// MARK: - FillNodeProperties
+
+final class FillNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(fill: Fill) {
+    keypathName = fill.name
+    color = NodeProperty(provider: KeyframeInterpolator(keyframes: fill.color.keyframes))
+    opacity = NodeProperty(provider: KeyframeInterpolator(keyframes: fill.opacity.keyframes))
+    type = fill.fillRule
+    keypathProperties = [
+      "Opacity" : opacity,
+      PropertyName.color.rawValue : color,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  let opacity: NodeProperty<Vector1D>
+  let color: NodeProperty<Color>
+  let type: FillRule
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+}
+
+// MARK: - FillNode
+
+final class FillNode: AnimatorNode, RenderNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, fill: Fill) {
+    fillRender = FillRenderer(parent: parentNode?.outputNode)
+    fillProperties = FillNodeProperties(fill: fill)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  let fillRender: FillRenderer
+
+  let fillProperties: FillNodeProperties
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  var renderer: NodeOutput & Renderable {
+    fillRender
+  }
+
+  // MARK: Animator Node Protocol
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    fillProperties
+  }
+
+  var isEnabled = true {
+    didSet {
+      fillRender.isEnabled = isEnabled
+    }
+  }
+
+  func localUpdatesPermeateDownstream() -> Bool {
+    false
+  }
+
+  func rebuildOutputs(frame _: CGFloat) {
+    fillRender.color = fillProperties.color.value.cgColorValue
+    fillRender.opacity = fillProperties.opacity.value.cgFloatValue * 0.01
+    fillRender.fillRule = fillProperties.type
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/RenderNodes/GradientFillNode.swift

@@ -0,0 +1,102 @@
+//
+//  GradientFillNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/22/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - GradientFillProperties
+
+final class GradientFillProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(gradientfill: GradientFill) {
+    keypathName = gradientfill.name
+    opacity = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientfill.opacity.keyframes))
+    startPoint = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientfill.startPoint.keyframes))
+    endPoint = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientfill.endPoint.keyframes))
+    colors = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientfill.colors.keyframes))
+    gradientType = gradientfill.gradientType
+    numberOfColors = gradientfill.numberOfColors
+    keypathProperties = [
+      "Opacity" : opacity,
+      "Start Point" : startPoint,
+      "End Point" : endPoint,
+      "Colors" : colors,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  let opacity: NodeProperty<Vector1D>
+  let startPoint: NodeProperty<Vector3D>
+  let endPoint: NodeProperty<Vector3D>
+  let colors: NodeProperty<[Double]>
+
+  let gradientType: GradientType
+  let numberOfColors: Int
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+}
+
+// MARK: - GradientFillNode
+
+final class GradientFillNode: AnimatorNode, RenderNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, gradientFill: GradientFill) {
+    fillRender = GradientFillRenderer(parent: parentNode?.outputNode)
+    fillProperties = GradientFillProperties(gradientfill: gradientFill)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  let fillRender: GradientFillRenderer
+
+  let fillProperties: GradientFillProperties
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  var renderer: NodeOutput & Renderable {
+    fillRender
+  }
+
+  // MARK: Animator Node Protocol
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    fillProperties
+  }
+
+  var isEnabled = true {
+    didSet {
+      fillRender.isEnabled = isEnabled
+    }
+  }
+
+  func localUpdatesPermeateDownstream() -> Bool {
+    false
+  }
+
+  func rebuildOutputs(frame _: CGFloat) {
+    fillRender.start = fillProperties.startPoint.value.pointValue
+    fillRender.end = fillProperties.endPoint.value.pointValue
+    fillRender.opacity = fillProperties.opacity.value.cgFloatValue * 0.01
+    fillRender.colors = fillProperties.colors.value.map { CGFloat($0) }
+    fillRender.type = fillProperties.gradientType
+    fillRender.numberOfColors = fillProperties.numberOfColors
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/RenderNodes/GradientStrokeNode.swift

@@ -0,0 +1,151 @@
+//
+//  GradientStrokeNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/23/19.
+//
+
+import CoreGraphics
+import Foundation
+
+// MARK: - GradientStrokeProperties
+
+final class GradientStrokeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(gradientStroke: GradientStroke) {
+    keypathName = gradientStroke.name
+    opacity = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientStroke.opacity.keyframes))
+    startPoint = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientStroke.startPoint.keyframes))
+    endPoint = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientStroke.endPoint.keyframes))
+    colors = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientStroke.colors.keyframes))
+    gradientType = gradientStroke.gradientType
+    numberOfColors = gradientStroke.numberOfColors
+    width = NodeProperty(provider: KeyframeInterpolator(keyframes: gradientStroke.width.keyframes))
+    miterLimit = CGFloat(gradientStroke.miterLimit)
+    lineCap = gradientStroke.lineCap
+    lineJoin = gradientStroke.lineJoin
+
+    if let dashes = gradientStroke.dashPattern {
+      var dashPatterns = ContiguousArray<ContiguousArray<Keyframe<Vector1D>>>()
+      var dashPhase = ContiguousArray<Keyframe<Vector1D>>()
+      for dash in dashes {
+        if dash.type == .offset {
+          dashPhase = dash.value.keyframes
+        } else {
+          dashPatterns.append(dash.value.keyframes)
+        }
+      }
+      dashPattern = NodeProperty(provider: GroupInterpolator(keyframeGroups: dashPatterns))
+      self.dashPhase = NodeProperty(provider: KeyframeInterpolator(keyframes: dashPhase))
+    } else {
+      dashPattern = NodeProperty(provider: SingleValueProvider([Vector1D]()))
+      dashPhase = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+    }
+    keypathProperties = [
+      "Opacity" : opacity,
+      "Start Point" : startPoint,
+      "End Point" : endPoint,
+      "Colors" : colors,
+      "Stroke Width" : width,
+      "Dashes" : dashPattern,
+      "Dash Phase" : dashPhase,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  var keypathName: String
+
+  let opacity: NodeProperty<Vector1D>
+  let startPoint: NodeProperty<Vector3D>
+  let endPoint: NodeProperty<Vector3D>
+  let colors: NodeProperty<[Double]>
+  let width: NodeProperty<Vector1D>
+
+  let dashPattern: NodeProperty<[Vector1D]>
+  let dashPhase: NodeProperty<Vector1D>
+
+  let lineCap: LineCap
+  let lineJoin: LineJoin
+  let miterLimit: CGFloat
+  let gradientType: GradientType
+  let numberOfColors: Int
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+}
+
+// MARK: - GradientStrokeNode
+
+final class GradientStrokeNode: AnimatorNode, RenderNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, gradientStroke: GradientStroke) {
+    strokeRender = GradientStrokeRenderer(parent: parentNode?.outputNode)
+    strokeProperties = GradientStrokeProperties(gradientStroke: gradientStroke)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  let strokeRender: GradientStrokeRenderer
+
+  let strokeProperties: GradientStrokeProperties
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  var renderer: NodeOutput & Renderable {
+    strokeRender
+  }
+
+  // MARK: Animator Node Protocol
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    strokeProperties
+  }
+
+  var isEnabled = true {
+    didSet {
+      strokeRender.isEnabled = isEnabled
+    }
+  }
+
+  func localUpdatesPermeateDownstream() -> Bool {
+    false
+  }
+
+  func rebuildOutputs(frame _: CGFloat) {
+    /// Update gradient properties
+    strokeRender.gradientRender.start = strokeProperties.startPoint.value.pointValue
+    strokeRender.gradientRender.end = strokeProperties.endPoint.value.pointValue
+    strokeRender.gradientRender.opacity = strokeProperties.opacity.value.cgFloatValue
+    strokeRender.gradientRender.colors = strokeProperties.colors.value.map { CGFloat($0) }
+    strokeRender.gradientRender.type = strokeProperties.gradientType
+    strokeRender.gradientRender.numberOfColors = strokeProperties.numberOfColors
+
+    /// Now update stroke properties
+    strokeRender.strokeRender.opacity = strokeProperties.opacity.value.cgFloatValue
+    strokeRender.strokeRender.width = strokeProperties.width.value.cgFloatValue
+    strokeRender.strokeRender.miterLimit = strokeProperties.miterLimit
+    strokeRender.strokeRender.lineCap = strokeProperties.lineCap
+    strokeRender.strokeRender.lineJoin = strokeProperties.lineJoin
+
+    /// Get dash lengths
+    let dashLengths = strokeProperties.dashPattern.value.map { $0.cgFloatValue }
+    if dashLengths.count > 0 {
+      strokeRender.strokeRender.dashPhase = strokeProperties.dashPhase.value.cgFloatValue
+      strokeRender.strokeRender.dashLengths = dashLengths
+    } else {
+      strokeRender.strokeRender.dashLengths = nil
+      strokeRender.strokeRender.dashPhase = nil
+    }
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/RenderNodes/StrokeNode.swift

@@ -0,0 +1,153 @@
+//
+//  StrokeNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/22/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - StrokeNodeProperties
+
+final class StrokeNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(stroke: Stroke) {
+    keypathName = stroke.name
+    color = NodeProperty(provider: KeyframeInterpolator(keyframes: stroke.color.keyframes))
+    opacity = NodeProperty(provider: KeyframeInterpolator(keyframes: stroke.opacity.keyframes))
+    width = NodeProperty(provider: KeyframeInterpolator(keyframes: stroke.width.keyframes))
+    miterLimit = CGFloat(stroke.miterLimit)
+    lineCap = stroke.lineCap
+    lineJoin = stroke.lineJoin
+
+    if let dashes = stroke.dashPattern {
+      let (dashPatterns, dashPhase) = dashes.shapeLayerConfiguration
+      dashPattern = NodeProperty(provider: GroupInterpolator(keyframeGroups: dashPatterns))
+      if dashPhase.count == 0 {
+        self.dashPhase = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+      } else {
+        self.dashPhase = NodeProperty(provider: KeyframeInterpolator(keyframes: dashPhase))
+      }
+    } else {
+      dashPattern = NodeProperty(provider: SingleValueProvider([Vector1D]()))
+      dashPhase = NodeProperty(provider: SingleValueProvider(Vector1D(0)))
+    }
+    keypathProperties = [
+      "Opacity" : opacity,
+      PropertyName.color.rawValue : color,
+      "Stroke Width" : width,
+      "Dashes" : dashPattern,
+      "Dash Phase" : dashPhase,
+    ]
+    properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  let keypathName: String
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+  let opacity: NodeProperty<Vector1D>
+  let color: NodeProperty<Color>
+  let width: NodeProperty<Vector1D>
+
+  let dashPattern: NodeProperty<[Vector1D]>
+  let dashPhase: NodeProperty<Vector1D>
+
+  let lineCap: LineCap
+  let lineJoin: LineJoin
+  let miterLimit: CGFloat
+
+}
+
+// MARK: - StrokeNode
+
+/// Node that manages stroking a path
+final class StrokeNode: AnimatorNode, RenderNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: AnimatorNode?, stroke: Stroke) {
+    strokeRender = StrokeRenderer(parent: parentNode?.outputNode)
+    strokeProperties = StrokeNodeProperties(stroke: stroke)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  let strokeRender: StrokeRenderer
+
+  let strokeProperties: StrokeNodeProperties
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+
+  var renderer: NodeOutput & Renderable {
+    strokeRender
+  }
+
+  // MARK: Animator Node Protocol
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    strokeProperties
+  }
+
+  var isEnabled = true {
+    didSet {
+      strokeRender.isEnabled = isEnabled
+    }
+  }
+
+  func localUpdatesPermeateDownstream() -> Bool {
+    false
+  }
+
+  func rebuildOutputs(frame _: CGFloat) {
+    strokeRender.color = strokeProperties.color.value.cgColorValue
+    strokeRender.opacity = strokeProperties.opacity.value.cgFloatValue * 0.01
+    strokeRender.width = strokeProperties.width.value.cgFloatValue
+    strokeRender.miterLimit = strokeProperties.miterLimit
+    strokeRender.lineCap = strokeProperties.lineCap
+    strokeRender.lineJoin = strokeProperties.lineJoin
+
+    /// Get dash lengths
+    let dashLengths = strokeProperties.dashPattern.value.map { $0.cgFloatValue }
+    if dashLengths.count > 0 {
+      strokeRender.dashPhase = strokeProperties.dashPhase.value.cgFloatValue
+      strokeRender.dashLengths = dashLengths
+    } else {
+      strokeRender.dashLengths = nil
+      strokeRender.dashPhase = nil
+    }
+  }
+
+}
+
+// MARK: - [DashElement] + shapeLayerConfiguration
+
+extension Array where Element == DashElement {
+  typealias ShapeLayerConfiguration = (
+    dashPatterns: ContiguousArray<ContiguousArray<Keyframe<Vector1D>>>,
+    dashPhase: ContiguousArray<Keyframe<Vector1D>>)
+
+  /// Converts the `[DashElement]` data model into `lineDashPattern` and `lineDashPhase`
+  /// representations usable in a `CAShapeLayer`
+  var shapeLayerConfiguration: ShapeLayerConfiguration {
+    var dashPatterns = ContiguousArray<ContiguousArray<Keyframe<Vector1D>>>()
+    var dashPhase = ContiguousArray<Keyframe<Vector1D>>()
+    for dash in self {
+      if dash.type == .offset {
+        dashPhase = dash.value.keyframes
+      } else {
+        dashPatterns.append(dash.value.keyframes)
+      }
+    }
+    return (dashPatterns, dashPhase)
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Nodes/Text/TextAnimatorNode.swift

@@ -0,0 +1,270 @@
+//
+//  TextAnimatorNode.swift
+//  lottie-ios-iOS
+//
+//  Created by Brandon Withrow on 2/19/19.
+//
+
+import CoreGraphics
+import Foundation
+import QuartzCore
+
+// MARK: - TextAnimatorNodeProperties
+
+final class TextAnimatorNodeProperties: NodePropertyMap, KeypathSearchable {
+
+  // MARK: Lifecycle
+
+  init(textAnimator: TextAnimator) {
+    keypathName = textAnimator.name
+    var properties = [String : AnyNodeProperty]()
+
+    if let keyframeGroup = textAnimator.anchor {
+      anchor = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Anchor"] = anchor
+    } else {
+      anchor = nil
+    }
+
+    if let keyframeGroup = textAnimator.position {
+      position = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Position"] = position
+    } else {
+      position = nil
+    }
+
+    if let keyframeGroup = textAnimator.scale {
+      scale = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Scale"] = scale
+    } else {
+      scale = nil
+    }
+
+    if let keyframeGroup = textAnimator.skew {
+      skew = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Skew"] = skew
+    } else {
+      skew = nil
+    }
+
+    if let keyframeGroup = textAnimator.skewAxis {
+      skewAxis = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Skew Axis"] = skewAxis
+    } else {
+      skewAxis = nil
+    }
+
+    if let keyframeGroup = textAnimator.rotation {
+      rotation = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Rotation"] = rotation
+    } else {
+      rotation = nil
+    }
+
+    if let keyframeGroup = textAnimator.opacity {
+      opacity = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Opacity"] = opacity
+    } else {
+      opacity = nil
+    }
+
+    if let keyframeGroup = textAnimator.strokeColor {
+      strokeColor = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Stroke Color"] = strokeColor
+    } else {
+      strokeColor = nil
+    }
+
+    if let keyframeGroup = textAnimator.fillColor {
+      fillColor = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Fill Color"] = fillColor
+    } else {
+      fillColor = nil
+    }
+
+    if let keyframeGroup = textAnimator.strokeWidth {
+      strokeWidth = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Stroke Width"] = strokeWidth
+    } else {
+      strokeWidth = nil
+    }
+
+    if let keyframeGroup = textAnimator.tracking {
+      tracking = NodeProperty(provider: KeyframeInterpolator(keyframes: keyframeGroup.keyframes))
+      properties["Tracking"] = tracking
+    } else {
+      tracking = nil
+    }
+
+    keypathProperties = properties
+
+    self.properties = Array(keypathProperties.values)
+  }
+
+  // MARK: Internal
+
+  let keypathName: String
+
+  let anchor: NodeProperty<Vector3D>?
+  let position: NodeProperty<Vector3D>?
+  let scale: NodeProperty<Vector3D>?
+  let skew: NodeProperty<Vector1D>?
+  let skewAxis: NodeProperty<Vector1D>?
+  let rotation: NodeProperty<Vector1D>?
+  let opacity: NodeProperty<Vector1D>?
+  let strokeColor: NodeProperty<Color>?
+  let fillColor: NodeProperty<Color>?
+  let strokeWidth: NodeProperty<Vector1D>?
+  let tracking: NodeProperty<Vector1D>?
+
+  let keypathProperties: [String: AnyNodeProperty]
+  let properties: [AnyNodeProperty]
+
+  var caTransform: CATransform3D {
+    CATransform3D.makeTransform(
+      anchor: anchor?.value.pointValue ?? .zero,
+      position: position?.value.pointValue ?? .zero,
+      scale: scale?.value.sizeValue ?? CGSize(width: 100, height: 100),
+      rotation: rotation?.value.cgFloatValue ?? 0,
+      skew: skew?.value.cgFloatValue,
+      skewAxis: skewAxis?.value.cgFloatValue)
+  }
+}
+
+// MARK: - TextOutputNode
+
+final class TextOutputNode: NodeOutput {
+
+  // MARK: Lifecycle
+
+  init(parent: TextOutputNode?) {
+    parentTextNode = parent
+  }
+
+  // MARK: Internal
+
+  var parentTextNode: TextOutputNode?
+  var isEnabled = true
+
+  var outputPath: CGPath?
+
+  var parent: NodeOutput? {
+    parentTextNode
+  }
+
+  var xform: CATransform3D {
+    get {
+      _xform ?? parentTextNode?.xform ?? CATransform3DIdentity
+    }
+    set {
+      _xform = newValue
+    }
+  }
+
+  var opacity: CGFloat {
+    get {
+      _opacity ?? parentTextNode?.opacity ?? 1
+    }
+    set {
+      _opacity = newValue
+    }
+  }
+
+  var strokeColor: CGColor? {
+    get {
+      _strokeColor ?? parentTextNode?.strokeColor
+    }
+    set {
+      _strokeColor = newValue
+    }
+  }
+
+  var fillColor: CGColor? {
+    get {
+      _fillColor ?? parentTextNode?.fillColor
+    }
+    set {
+      _fillColor = newValue
+    }
+  }
+
+  var tracking: CGFloat {
+    get {
+      _tracking ?? parentTextNode?.tracking ?? 0
+    }
+    set {
+      _tracking = newValue
+    }
+  }
+
+  var strokeWidth: CGFloat {
+    get {
+      _strokeWidth ?? parentTextNode?.strokeWidth ?? 0
+    }
+    set {
+      _strokeWidth = newValue
+    }
+  }
+
+  func hasOutputUpdates(_: CGFloat) -> Bool {
+    // TODO Fix This
+    true
+  }
+
+  // MARK: Fileprivate
+
+  fileprivate var _xform: CATransform3D?
+  fileprivate var _opacity: CGFloat?
+  fileprivate var _strokeColor: CGColor?
+  fileprivate var _fillColor: CGColor?
+  fileprivate var _tracking: CGFloat?
+  fileprivate var _strokeWidth: CGFloat?
+}
+
+// MARK: - TextAnimatorNode
+
+class TextAnimatorNode: AnimatorNode {
+
+  // MARK: Lifecycle
+
+  init(parentNode: TextAnimatorNode?, textAnimator: TextAnimator) {
+    textOutputNode = TextOutputNode(parent: parentNode?.textOutputNode)
+    textAnimatorProperties = TextAnimatorNodeProperties(textAnimator: textAnimator)
+    self.parentNode = parentNode
+  }
+
+  // MARK: Internal
+
+  let textOutputNode: TextOutputNode
+
+  let textAnimatorProperties: TextAnimatorNodeProperties
+
+  let parentNode: AnimatorNode?
+  var hasLocalUpdates = false
+  var hasUpstreamUpdates = false
+  var lastUpdateFrame: CGFloat? = nil
+  var isEnabled = true
+
+  var outputNode: NodeOutput {
+    textOutputNode
+  }
+
+  // MARK: Animator Node Protocol
+
+  var propertyMap: NodePropertyMap & KeypathSearchable {
+    textAnimatorProperties
+  }
+
+  func localUpdatesPermeateDownstream() -> Bool {
+    true
+  }
+
+  func rebuildOutputs(frame _: CGFloat) {
+    textOutputNode.xform = textAnimatorProperties.caTransform
+    textOutputNode.opacity = (textAnimatorProperties.opacity?.value.cgFloatValue ?? 100) * 0.01
+    textOutputNode.strokeColor = textAnimatorProperties.strokeColor?.value.cgColorValue
+    textOutputNode.fillColor = textAnimatorProperties.fillColor?.value.cgColorValue
+    textOutputNode.tracking = textAnimatorProperties.tracking?.value.cgFloatValue ?? 1
+    textOutputNode.strokeWidth = textAnimatorProperties.strokeWidth?.value.cgFloatValue ?? 0
+  }
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Protocols/AnimatorNode.swift

@@ -0,0 +1,198 @@
+//
+//  AnimatorNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/15/19.
+//
+
+import Foundation
+import QuartzCore
+
+// MARK: - NodeOutput
+
+/// Defines the basic outputs of an animator node.
+///
+protocol NodeOutput {
+
+  /// The parent node.
+  var parent: NodeOutput? { get }
+
+  /// Returns true if there are any updates upstream. OutputPath must be built before returning.
+  func hasOutputUpdates(_ forFrame: CGFloat) -> Bool
+
+  var outputPath: CGPath? { get }
+
+  var isEnabled: Bool { get set }
+}
+
+// MARK: - AnimatorNode
+
+/// The Animator Node is the base node in the render system tree.
+///
+/// It defines a single node that has an output path and option input node.
+/// At animation time the root animation node is asked to update its contents for
+/// the current frame.
+/// The node reaches up its chain of nodes until the first node that does not need
+/// updating is found. Then each node updates its contents down the render pipeline.
+/// Each node adds its local path to its input path and passes it forward.
+///
+/// An animator node holds a group of interpolators. These interpolators determine
+/// if the node needs an update for the current frame.
+///
+protocol AnimatorNode: AnyObject, KeypathSearchable {
+
+  /// The available properties of the Node.
+  ///
+  /// These properties are automatically updated each frame.
+  /// These properties are also settable and gettable through the dynamic
+  /// property system.
+  ///
+  var propertyMap: NodePropertyMap & KeypathSearchable { get }
+
+  /// The upstream input node
+  var parentNode: AnimatorNode? { get }
+
+  /// The output of the node.
+  var outputNode: NodeOutput { get }
+
+  /// Update the outputs of the node. Called if local contents were update or if outputsNeedUpdate returns true.
+  func rebuildOutputs(frame: CGFloat)
+
+  /// Setters for marking current node state.
+  var isEnabled: Bool { get set }
+  var hasLocalUpdates: Bool { get set }
+  var hasUpstreamUpdates: Bool { get set }
+  var lastUpdateFrame: CGFloat? { get set }
+
+  // MARK: Optional
+
+  /// Marks if updates to this node affect nodes downstream.
+  func localUpdatesPermeateDownstream() -> Bool
+  func forceUpstreamOutputUpdates() -> Bool
+
+  /// Called at the end of this nodes update cycle. Always called. Optional.
+  func performAdditionalLocalUpdates(frame: CGFloat, forceLocalUpdate: Bool) -> Bool
+  func performAdditionalOutputUpdates(_ frame: CGFloat, forceOutputUpdate: Bool)
+
+  /// The default simply returns `hasLocalUpdates`
+  func shouldRebuildOutputs(frame: CGFloat) -> Bool
+}
+
+/// Basic Node Logic
+extension AnimatorNode {
+
+  func shouldRebuildOutputs(frame _: CGFloat) -> Bool {
+    hasLocalUpdates
+  }
+
+  func localUpdatesPermeateDownstream() -> Bool {
+    /// Optional override
+    true
+  }
+
+  func forceUpstreamOutputUpdates() -> Bool {
+    /// Optional
+    false
+  }
+
+  func performAdditionalLocalUpdates(frame _: CGFloat, forceLocalUpdate: Bool) -> Bool {
+    /// Optional
+    forceLocalUpdate
+  }
+
+  func performAdditionalOutputUpdates(_: CGFloat, forceOutputUpdate _: Bool) {
+    /// Optional
+  }
+
+  @discardableResult
+  func updateOutputs(_ frame: CGFloat, forceOutputUpdate: Bool) -> Bool {
+    guard isEnabled else {
+      // Disabled node, pass through.
+      lastUpdateFrame = frame
+      return parentNode?.updateOutputs(frame, forceOutputUpdate: forceOutputUpdate) ?? false
+    }
+
+    if forceOutputUpdate == false && lastUpdateFrame != nil && lastUpdateFrame! == frame {
+      /// This node has already updated for this frame. Go ahead and return the results.
+      return hasUpstreamUpdates || hasLocalUpdates
+    }
+
+    /// Ask if this node should force output updates upstream.
+    let forceUpstreamUpdates = forceOutputUpdate || forceUpstreamOutputUpdates()
+
+    /// Perform upstream output updates. Optionally mark upstream updates if any.
+    hasUpstreamUpdates = (
+      parentNode?
+        .updateOutputs(frame, forceOutputUpdate: forceUpstreamUpdates) ?? false || hasUpstreamUpdates)
+
+    /// Perform additional local output updates
+    performAdditionalOutputUpdates(frame, forceOutputUpdate: forceUpstreamUpdates)
+
+    /// If there are local updates, or if updates have been force, rebuild outputs
+    if forceUpstreamUpdates || shouldRebuildOutputs(frame: frame) {
+      lastUpdateFrame = frame
+      rebuildOutputs(frame: frame)
+    }
+    return hasUpstreamUpdates || hasLocalUpdates
+  }
+
+  /// Rebuilds the content of this node, and upstream nodes if necessary.
+  @discardableResult
+  func updateContents(_ frame: CGFloat, forceLocalUpdate: Bool) -> Bool {
+    guard isEnabled else {
+      // Disabled node, pass through.
+      return parentNode?.updateContents(frame, forceLocalUpdate: forceLocalUpdate) ?? false
+    }
+
+    if forceLocalUpdate == false && lastUpdateFrame != nil && lastUpdateFrame! == frame {
+      /// This node has already updated for this frame. Go ahead and return the results.
+      return localUpdatesPermeateDownstream() ? hasUpstreamUpdates || hasLocalUpdates : hasUpstreamUpdates
+    }
+
+    /// Are there local updates? If so mark the node.
+    hasLocalUpdates = forceLocalUpdate ? forceLocalUpdate : propertyMap.needsLocalUpdate(frame: frame)
+
+    /// Were there upstream updates? If so mark the node
+    hasUpstreamUpdates = parentNode?.updateContents(frame, forceLocalUpdate: forceLocalUpdate) ?? false
+
+    /// Perform property updates if necessary.
+    if hasLocalUpdates {
+      /// Rebuild local properties
+      propertyMap.updateNodeProperties(frame: frame)
+    }
+
+    /// Ask the node to perform any other updates it might have.
+    hasUpstreamUpdates = performAdditionalLocalUpdates(frame: frame, forceLocalUpdate: forceLocalUpdate) || hasUpstreamUpdates
+
+    /// If the node can update nodes downstream, notify them, otherwise pass on any upstream updates downstream.
+    return localUpdatesPermeateDownstream() ? hasUpstreamUpdates || hasLocalUpdates : hasUpstreamUpdates
+  }
+
+  func updateTree(_ frame: CGFloat, forceUpdates: Bool = false) {
+    updateContents(frame, forceLocalUpdate: forceUpdates)
+    updateOutputs(frame, forceOutputUpdate: forceUpdates)
+  }
+
+}
+
+extension AnimatorNode {
+  /// Default implementation for Keypath searchable.
+  /// Forward all calls to the propertyMap.
+
+  var keypathName: String {
+    propertyMap.keypathName
+  }
+
+  var keypathProperties: [String: AnyNodeProperty] {
+    propertyMap.keypathProperties
+  }
+
+  var childKeypaths: [KeypathSearchable] {
+    propertyMap.childKeypaths
+  }
+
+  var keypathLayer: CALayer? {
+    nil
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Protocols/PathNode.swift

@@ -0,0 +1,22 @@
+//
+//  PathNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/17/19.
+//
+
+import Foundation
+
+// MARK: - PathNode
+
+protocol PathNode {
+  var pathOutput: PathOutputNode { get }
+}
+
+extension PathNode where Self: AnimatorNode {
+
+  var outputNode: NodeOutput {
+    pathOutput
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/Protocols/RenderNode.swift

@@ -0,0 +1,62 @@
+//
+//  RenderNode.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/17/19.
+//
+
+import CoreGraphics
+import Foundation
+import QuartzCore
+
+// MARK: - RenderNode
+
+/// A protocol that defines a node that holds render instructions
+protocol RenderNode {
+  var renderer: Renderable & NodeOutput { get }
+}
+
+// MARK: - Renderable
+
+/// A protocol that defines anything with render instructions
+protocol Renderable {
+
+  /// The last frame in which this node was updated.
+  var hasUpdate: Bool { get }
+
+  func hasRenderUpdates(_ forFrame: CGFloat) -> Bool
+
+  /// Determines if the renderer requires a custom context for drawing.
+  /// If yes the shape layer will perform a custom drawing pass.
+  /// If no the shape layer will be a standard CAShapeLayer
+  var shouldRenderInContext: Bool { get }
+
+  /// Passes in the CAShapeLayer to update
+  func updateShapeLayer(layer: CAShapeLayer)
+
+  /// Asks the renderer what the renderable bounds is for the given box.
+  func renderBoundsFor(_ boundingBox: CGRect) -> CGRect
+
+  /// Opportunity for renderers to inject sublayers
+  func setupSublayers(layer: CAShapeLayer)
+
+  /// Renders the shape in a custom context
+  func render(_ inContext: CGContext)
+}
+
+extension RenderNode where Self: AnimatorNode {
+
+  var outputNode: NodeOutput {
+    renderer
+  }
+
+}
+
+extension Renderable {
+
+  func renderBoundsFor(_ boundingBox: CGRect) -> CGRect {
+    /// Optional
+    boundingBox
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/RenderLayers/ShapeContainerLayer.swift

@@ -0,0 +1,75 @@
+//
+//  ShapeContainerLayer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/30/19.
+//
+
+import Foundation
+import QuartzCore
+
+/// The base layer that holds Shapes and Shape Renderers
+class ShapeContainerLayer: CALayer {
+
+  // MARK: Lifecycle
+
+  override init() {
+    super.init()
+    actions = [
+      "position" : NSNull(),
+      "bounds" : NSNull(),
+      "anchorPoint" : NSNull(),
+      "transform" : NSNull(),
+      "opacity" : NSNull(),
+      "hidden" : NSNull(),
+    ]
+  }
+
+  required init?(coder _: NSCoder) {
+    fatalError("init(coder:) has not been implemented")
+  }
+
+  override init(layer: Any) {
+    guard let layer = layer as? ShapeContainerLayer else {
+      fatalError("init(layer:) wrong class.")
+    }
+    super.init(layer: layer)
+  }
+
+  // MARK: Internal
+
+  private(set) var renderLayers: [ShapeContainerLayer] = []
+
+  var renderScale: CGFloat = 1 {
+    didSet {
+      updateRenderScale()
+    }
+  }
+
+  func insertRenderLayer(_ layer: ShapeContainerLayer) {
+    renderLayers.append(layer)
+    insertSublayer(layer, at: 0)
+  }
+
+  func markRenderUpdates(forFrame: CGFloat) {
+    if hasRenderUpdate(forFrame: forFrame) {
+      rebuildContents(forFrame: forFrame)
+    }
+    guard isHidden == false else { return }
+    renderLayers.forEach { $0.markRenderUpdates(forFrame: forFrame) }
+  }
+
+  func hasRenderUpdate(forFrame _: CGFloat) -> Bool {
+    false
+  }
+
+  func rebuildContents(forFrame _: CGFloat) {
+    /// Override
+  }
+
+  func updateRenderScale() {
+    contentsScale = renderScale
+    renderLayers.forEach( { $0.renderScale = renderScale } )
+  }
+
+}

submodules/lottie-ios/Sources/Private/MainThread/NodeRenderSystem/RenderLayers/ShapeRenderLayer.swift

@@ -0,0 +1,100 @@
+//
+//  RenderLayer.swift
+//  lottie-swift
+//
+//  Created by Brandon Withrow on 1/18/19.
+//
+
+import Foundation
+import QuartzCore
+
+/// The layer responsible for rendering shape objects
+final class ShapeRenderLayer: ShapeContainerLayer {
+
+  // MARK: Lifecycle
+
+  init(renderer: Renderable & NodeOutput) {
+    self.renderer = renderer
+    super.init()
+    anchorPoint = .zero
+    actions = [
+      "position" : NSNull(),
+      "bounds" : NSNull(),
+      "anchorPoint" : NSNull(),
+      "path" : NSNull(),
+      "transform" : NSNull(),
+      "opacity" : NSNull(),
+      "hidden" : NSNull(),
+    ]
+    shapeLayer.actions = [
+      "position" : NSNull(),
+      "bounds" : NSNull(),
+      "anchorPoint" : NSNull(),
+      "path" : NSNull(),
+      "fillColor" : NSNull(),
+      "strokeColor" : NSNull(),
+      "lineWidth" : NSNull(),
+      "miterLimit" : NSNull(),
+      "lineDashPhase" : NSNull(),
+      "opacity": NSNull(),
+      "hidden" : NSNull(),
+    ]
+    addSublayer(shapeLayer)
+
+    renderer.setupSublayers(layer: shapeLayer)
+  }
+
+  override init(layer: Any) {
+    guard let layer = layer as? ShapeRenderLayer else {
+      fatalError("init(layer:) wrong class.")
+    }
+    renderer = layer.renderer
+    super.init(layer: layer)
+  }
+
+  required init?(coder _: NSCoder) {
+    fatalError("init(coder:) has not been implemented")
+  }
+
+  // MARK: Internal
+
+  fileprivate(set) var renderer: Renderable & NodeOutput
+
+  let shapeLayer = CAShapeLayer()
+
+  override func hasRenderUpdate(forFrame: CGFloat) -> Bool {
+    isHidden = !renderer.isEnabled
+    guard isHidden == false else { return false }
+    return renderer.hasRenderUpdates(forFrame)
+  }
+
+  override func rebuildContents(forFrame _: CGFloat) {
+
+    if renderer.shouldRenderInContext {
+      if let newPath = renderer.outputPath {
+        bounds = renderer.renderBoundsFor(newPath.boundingBox)
+      } else {
+        bounds = .zero
+      }
+      position = bounds.origin
+      setNeedsDisplay()
+    } else {
+      shapeLayer.path = renderer.outputPath
+      renderer.updateShapeLayer(layer: shapeLayer)
+    }
+  }
+
+  override func draw(in ctx: CGContext) {
+    if let path = renderer.outputPath {
+      if !path.isEmpty {
+        ctx.addPath(path)
+      }
+    }
+    renderer.render(ctx)
+  }
+
+  override func updateRenderScale() {
+    super.updateRenderScale()
+    shapeLayer.contentsScale = renderScale
+  }
+}