that took way too long

Author: bbrk24

Sources/SwiftCrossUI/Path.swift

@@ -49,6 +49,9 @@ public struct AffineTransform: Equatable, CustomDebugStringConvertible {
     /// [ x  y ]
     /// [ z  w ]
     /// ```
+    /// - Remark: The matrices in some graphics frameworks, such as WinUI's `Matrix` and
+    /// CoreGraphics' `CGAffineTransform`, take the transpose of this matrix. The reason for
+    /// this difference is left- vs right-multiplication; the values are identical.
     public var linearTransform: SIMD4<Double>
     /// The translation applied after the linear transformation.
     public var translation: SIMD2<Double>
@@ -73,14 +76,13 @@ public struct AffineTransform: Equatable, CustomDebugStringConvertible {
     }
 
     public static func rotation(radians: Double, center: SIMD2<Double>) -> AffineTransform {
-        // Making the sine negative so that positive rotations are clockwise
-        let sine = sin(-radians)
+        let sine = sin(radians)
         let cosine = cos(radians)
         return AffineTransform(
             linearTransform: SIMD4(x: cosine, y: -sine, z: sine, w: cosine),
             translation: SIMD2(
-                x: -center.x * cosine - center.y * sine + center.x,
-                y: center.x * sine - center.y * cosine + center.y
+                x: -center.x * cosine + center.y * sine + center.x,
+                y: -center.x * sine - center.y * cosine + center.y
             )
         )
     }
@@ -95,7 +97,8 @@ public struct AffineTransform: Equatable, CustomDebugStringConvertible {
     )
 
     public func inverted() -> AffineTransform? {
-        let determinant = linearTransform.x * linearTransform.w - linearTransform.y * linearTransform.z
+        let determinant =
+            linearTransform.x * linearTransform.w - linearTransform.y * linearTransform.z
         if determinant == 0.0 {
             return nil
         }

Sources/SwiftCrossUI/Views/Shapes/Shape.swift

@@ -40,7 +40,8 @@ extension Shape {
         let storage = children as! ShapeStorage
         let size = size(fitting: proposedSize)
 
-        let path = path(in: Path.Rect(x: 0.0, y: 0.0, width: Double(size.x), height: Double(size.y)))
+        let path = path(
+            in: Path.Rect(x: 0.0, y: 0.0, width: Double(size.x), height: Double(size.y)))
         let pointsChanged = storage.oldPath?.actions != path.actions
         storage.oldPath = path
 

Sources/UIKitBackend/UIKitBackend+Path.swift

@@ -78,16 +78,7 @@ extension UIKitBackend {
                             clockwise: clockwise
                         )
                     case .transform(let transform):
-                        path.apply(
-                            CGAffineTransform(
-                                a: transform.linearTransform.x,
-                                b: transform.linearTransform.y,
-                                c: transform.linearTransform.z,
-                                d: transform.linearTransform.w,
-                                tx: transform.translation.x,
-                                ty: transform.translation.y
-                            )
-                        )
+                        path.apply(CGAffineTransform(transform))
                 }
             }
         }
@@ -102,3 +93,25 @@ extension UIKitBackend {
         container.view.backgroundColor = environment.suggestedForegroundColor.uiColor
     }
 }
+
+extension CGAffineTransform {
+    public init(_ transform: AffineTransform) {
+        self.init(
+            a: transform.linearTransform.x,
+            b: transform.linearTransform.z,
+            c: transform.linearTransform.y,
+            d: transform.linearTransform.w,
+            tx: transform.translation.x,
+            ty: transform.translation.y
+        )
+    }
+}
+
+extension AffineTransform {
+    public init(cg transform: CGAffineTransform) {
+        self.init(
+            linearTransform: SIMD4(x: transform.a, y: transform.c, z: transform.b, w: transform.d),
+            translation: SIMD2(x: transform.tx, y: transform.ty)
+        )
+    }
+}