Add RendererEffect support

Example/OpenSwiftUIUITests/Render/GeometryEffect/IgnoredByLayoutEffectUITests.swift

@@ -0,0 +1,40 @@
+//
+//  IgnoredByLayoutEffectUITests.swift
+//  OpenSwiftUIUITests
+
+import Testing
+import SnapshotTesting
+
+@MainActor
+@Suite(.snapshots(record: .never, diffTool: diffTool))
+struct IgnoredByLayoutEffectUITests {
+    @Test(.disabled("Animation is not implmemented yet"))
+    func offsetIgnoredByLayout() {
+        struct ContentView: View {
+            var body: some View {
+                WobbleColorView()
+            }
+        }
+
+        struct WobbleEffect: GeometryEffect {
+            var amount: CGFloat = 10
+            var shakesPerUnit = 3
+            var animatableData: CGFloat
+
+            nonisolated func effectValue(size: CGSize) -> ProjectionTransform {
+                let translation = amount * sin(animatableData * .pi * CGFloat(shakesPerUnit))
+                return ProjectionTransform(CGAffineTransform(translationX: translation, y: 0))
+            }
+        }
+
+        struct WobbleColorView: View {
+            @State private var wobble = false
+
+            var body: some View {
+                Color.red.frame(width: 200, height: 200)
+                    .modifier(_OffsetEffect(offset: CGSize(width: 0, height: 100)).ignoredByLayout())
+            }
+        }
+        openSwiftUIAssertSnapshot(of: ContentView())
+    }
+}

Example/OpenSwiftUIUITests/Render/GeometryEffect/OffsetEffectUITests.swift

@@ -0,0 +1,24 @@
+//
+//  OffsetEffectUITests.swift
+//  OpenSwiftUIUITests
+
+import Testing
+import SnapshotTesting
+
+@MainActor
+@Suite(.snapshots(record: .never, diffTool: diffTool))
+struct OffsetEffectUITests {
+    @Test
+    func offsetWithFrame() {
+        struct ContentView: View {
+            var body: some View {
+                Color.blue
+                    .offset(x: 20, y: 15)
+                    .frame(width: 80, height: 60)
+                    .background(Color.red)
+                    .overlay(Color.green.offset(x: 40, y: 30))
+            }
+        }
+        openSwiftUIAssertSnapshot(of: ContentView())
+    }
+}

Sources/OpenSwiftUI/Render/GeometryEffect/IgnoredByLayoutEffect.swift

@@ -0,0 +1,55 @@
+//
+//  IgnoredByLayoutEffect.swift
+//  OpenSwiftUI
+//
+//  Audited for 6.5.4
+//  Status: Complete
+
+public import Foundation
+
+/// A geometry effect type that prevents another geometry effect
+/// affecting coordinate space conversions during layout, i.e. the
+/// transform introduced by the other effect is only used when
+/// rendering, not when converting locations from one view to another.
+/// This is often used to disable layout changes during transitions.
+@available(OpenSwiftUI_v1_0, *)
+@frozen
+public struct _IgnoredByLayoutEffect<Base>: GeometryEffect where Base: GeometryEffect {
+    public var base: Base
+
+    public static var _affectsLayout: Bool { false }
+
+    @inlinable
+    public init(_ base: Base) {
+        self.base = base
+    }
+
+    public func effectValue(size: CGSize) -> ProjectionTransform {
+        base.effectValue(size: size)
+    }
+
+    public var animatableData: Base.AnimatableData {
+        get { base.animatableData }
+        set { base.animatableData = newValue }
+    }
+}
+
+@available(*, unavailable)
+extension _IgnoredByLayoutEffect: Sendable {}
+
+@available(OpenSwiftUI_v1_0, *)
+extension _IgnoredByLayoutEffect: Equatable where Base: Equatable {}
+
+@available(OpenSwiftUI_v1_0, *)
+extension GeometryEffect {
+    /// Returns an effect that produces the same geometry transform as this
+    /// effect, but only applies the transform while rendering its view.
+    ///
+    /// Use this method to disable layout changes during transitions. The view
+    /// ignores the transform returned by this method while the view is
+    /// performing its layout calculations.
+    @inlinable
+    public func ignoredByLayout() -> _IgnoredByLayoutEffect<Self> {
+        return _IgnoredByLayoutEffect(self)
+    }
+}

Sources/OpenSwiftUICore/Data/Environment/EnvironmentAdditions.swift

@@ -7,6 +7,7 @@
 //  ID: 1B17C64D9E901A0054B49B69A4A2439D (SwiftUICore)
 
 public import Foundation
+package import OpenGraphShims
 
 // MARK: - EnvironmentValues + Display [6.4.41]
 
@@ -43,6 +44,12 @@ extension CachedEnvironment.ID {
     package static let pixelLength: CachedEnvironment.ID = .init()
 }
 
+extension _ViewInputs {
+    package var pixelLength: Attribute<CGFloat> {
+        mapEnvironment(id: .pixelLength) { $0.pixelLength }
+    }
+}
+
 private struct DisplayGamutKey: EnvironmentKey {
     static var defaultValue: DisplayGamut { .sRGB }
 }

Sources/OpenSwiftUICore/Render/DisplayList/DisplayList.swift

@@ -6,7 +6,9 @@
 //  Status: WIP
 //  ID: F37E3733E490AA5E3BDC045E3D34D9F8 (SwiftUICore)
 
+package import CoreGraphicsShims
 package import Foundation
+package import OpenGraphShims
 
 // MARK: - _DisplayList_Identity
 
@@ -98,7 +100,11 @@ package struct DisplayList: Equatable {
         // TODO
         items.append(contentsOf: other.items)
 //        _openSwiftUIUnimplementedFailure()
-    }    
+    }
+
+    package var isEmpty: Bool {
+        items.isEmpty
+    }
 }
 
 @available(*, unavailable)
@@ -204,9 +210,7 @@ extension DisplayList {
     }
 
     package enum Transform {
-        #if canImport(Darwin)
         case affine(CGAffineTransform)
-        #endif
         case projection(ProjectionTransform)
         // case rotation(_RotationEffect.Data)
         // case rotation3D(_Rotation3DEffect.Data)
@@ -428,6 +432,30 @@ extension DisplayList {
     }
 }
 
+extension PreferencesInputs {
+    @inline(__always)
+    package var requiresDisplayList: Bool {
+        get {
+            contains(DisplayList.Key.self)
+        }
+        set {
+            if newValue {
+                add(DisplayList.Key.self)
+            } else {
+                remove(DisplayList.Key.self)
+            }
+        }
+    }
+}
+
+extension PreferencesOutputs {
+    @inline(__always)
+    package var displayList: Attribute<DisplayList>? {
+        get { self[DisplayList.Key.self] }
+        set { self[DisplayList.Key.self] = newValue }
+    }
+}
+
 // MARK: - DisplayList.Item + Extension
 
 extension DisplayList.Item {

Sources/OpenSwiftUICore/Render/DisplayList/DisplayList_StableIdentity.swift

@@ -95,12 +95,24 @@ extension _DisplayList_StableIdentityMap: ProtobufMessage {
     }
 }
 
-// TODO: Blocked by _ViewInputs
-//extension _ViewInputs {
-//    package mutating func configureStableIDs(root: _DisplayList_StableIdentityRoot) {
-//    package func pushIdentity(_ identity: _DisplayList_Identity)
-//    package func makeStableIdentity() -> _DisplayList_StableIdentity
-//}
+extension _ViewInputs {
+    package mutating func configureStableIDs(root: _DisplayList_StableIdentityRoot) {
+        _openSwiftUIUnimplementedFailure()
+    }
+
+    package func pushIdentity(_ identity: _DisplayList_Identity) {
+
+        guard base.needsStableDisplayListIDs else {
+            return
+        }
+        self[_DisplayList_StableIdentityScope.self].attribute!.value.pushIdentity(identity)
+    }
+
+    package func makeStableIdentity() -> _DisplayList_StableIdentity {
+        // Log.internalError("expected stable IDs to be supported")
+        _openSwiftUIUnimplementedFailure()
+    }
+}
 
 extension _GraphInputs {
     private func pushScope<ID>(id: ID) where ID: StronglyHashable {
@@ -110,7 +122,7 @@ extension _GraphInputs {
     }
 
     package mutating func pushStableID<ID>(_ id: ID) where ID: Hashable {
-        guard options.contains(.needsStableDisplayListIDs) else {
+        guard needsStableDisplayListIDs else {
             return
         }
         if let stronglyHashable = id as? StronglyHashable {
@@ -121,35 +133,31 @@ extension _GraphInputs {
     }
 
     package mutating func pushStableIndex(_ index: Int) {
-        guard options.contains(.needsStableDisplayListIDs) else {
+        guard needsStableDisplayListIDs else {
             return
         }
         pushScope(id: index)
     }
 
     package mutating func pushStableType(_ type: any Any.Type) {
-        #if OPENSWIFTUI_SUPPORT_2024_API
-        guard options.contains(.needsStableDisplayListIDs) else {
+        guard needsStableDisplayListIDs else {
             return
         }
         pushScope(id: makeStableTypeData(type))
-        #endif
     }
 
     package var stableIDScope: WeakAttribute<DisplayList.StableIdentityScope>? {
-        guard !options.contains(.needsStableDisplayListIDs) else {
+        guard !needsStableDisplayListIDs else { // Question
             return nil
         }
         let result = self[_DisplayList_StableIdentityScope.self]
         return result.attribute == nil ? nil : result
     }
 }
 
-#if OPENSWIFTUI_SUPPORT_2024_API
 package func makeStableTypeData(_ type: any Any.Type) -> StrongHash {
     unsafeBitCast(Metadata(type).signature, to: StrongHash.self)
 }
-#endif
 
 package func makeStableIDData<ID>(from id: ID) -> StrongHash? {
     guard let encodable = id as? Encodable else {