Improve diffing of cameras and lights

Author: nicklockwood

ShapeScript/GeometryType.swift

@@ -9,23 +9,57 @@
 import Euclid
 
 public struct Camera: Hashable {
-    public var hasPosition: Bool
-    public var hasOrientation: Bool
-    public var hasScale: Bool
+    public var position: Vector?
+    public var orientation: Rotation?
+    public var scale: Vector?
     public var background: MaterialProperty?
     public var fov: Angle?
     public var width: Double?
     public var height: Double?
 }
 
+public extension Camera {
+    var hasPosition: Bool {
+        get { position != nil }
+        @available(*, deprecated, message: "Obsolete. Use position instead.")
+        set { position = newValue ? .zero : nil }
+    }
+
+    var hasOrientation: Bool {
+        get { orientation != nil }
+        @available(*, deprecated, message: "Obsolete. Use orientation instead.")
+        set { orientation = newValue ? .identity : nil }
+    }
+
+    var hasScale: Bool {
+        get { scale != nil }
+        @available(*, deprecated, message: "Obsolete. Use scale instead.")
+        set { scale = newValue ? .one : nil }
+    }
+}
+
 public struct Light: Hashable {
-    public var hasPosition: Bool
-    public var hasOrientation: Bool
+    public var position: Vector?
+    public var orientation: Rotation?
     public var color: Color
     public var spread: Angle
     public var penumbra: Double
 }
 
+public extension Light {
+    var hasPosition: Bool {
+        get { position != nil }
+        @available(*, deprecated, message: "Obsolete. Use position instead.")
+        set { position = newValue ? .zero : nil }
+    }
+
+    var hasOrientation: Bool {
+        get { orientation != nil }
+        @available(*, deprecated, message: "Obsolete. Use orientation instead.")
+        set { orientation = newValue ? .identity : nil }
+    }
+}
+
 public enum GeometryType: Hashable {
     case group
     // primitives

ShapeScript/Scene+SceneKit.swift

@@ -349,9 +349,9 @@ public extension Geometry {
                 transform.scale *= scnCamera.orthographicScale
             }
             type = .camera(Camera(
-                hasPosition: true,
-                hasOrientation: true,
-                hasScale: isOrtho,
+                position: transform.offset,
+                orientation: transform.rotation,
+                scale: isOrtho ? transform.scale : nil,
                 background: nil,
                 fov: .degrees(isOrtho ? 0 : Double(scnCamera.fieldOfView)),
                 width: nil,

ShapeScript/StandardLibrary.swift

@@ -142,19 +142,14 @@ extension Dictionary where Key == String, Value == Symbol {
             "spread": .number,
             "penumbra": .number,
         ])) { context in
-            var hasPosition = false, hasOrientation = false
-            if let position = context.value(for: "position")?.value as? Vector {
-                context.transform.offset = position
-                hasPosition = true
-            }
-            if let orientation = context.value(for: "orientation")?.value as? Rotation {
-                context.transform.rotation = orientation
-                hasOrientation = true
-            }
+            let position = context.value(for: "position")?.value as? Vector
+            position.map { context.transform.offset = $0 }
+            let orientation = context.value(for: "orientation")?.value as? Rotation
+            orientation.map { context.transform.rotation = $0 }
             return .mesh(Geometry(
                 type: .light(Light(
-                    hasPosition: hasPosition,
-                    hasOrientation: hasOrientation,
+                    position: position,
+                    orientation: orientation,
                     color: context.value(for: "color")?.colorValue ?? .white,
                     spread: context.value(for: "spread")?.angleValue ?? (.pi / 4),
                     penumbra: context.value(for: "penumbra")?.doubleValue ?? 1
@@ -405,24 +400,17 @@ extension Dictionary where Key == String, Value == Symbol {
             "width": .number,
             "height": .number,
         ])) { context in
-            var hasPosition = false, hasOrientation = false, hasScale = false
-            if let position = context.value(for: "position")?.value as? Vector {
-                context.transform.offset = position
-                hasPosition = true
-            }
-            if let orientation = context.value(for: "orientation")?.value as? Rotation {
-                context.transform.rotation = orientation
-                hasOrientation = true
-            }
-            if let size = context.value(for: "size")?.value as? Vector {
-                context.transform.scale = size
-                hasScale = true
-            }
+            let position = context.value(for: "position")?.value as? Vector
+            position.map { context.transform.offset = $0 }
+            let orientation = context.value(for: "orientation")?.value as? Rotation
+            orientation.map { context.transform.rotation = $0 }
+            let scale = context.value(for: "size")?.value as? Vector
+            scale.map { context.transform.scale = $0 }
             return .mesh(Geometry(
                 type: .camera(Camera(
-                    hasPosition: hasPosition,
-                    hasOrientation: hasOrientation,
-                    hasScale: hasScale,
+                    position: position,
+                    orientation: orientation,
+                    scale: scale,
                     background: context.background,
                     fov: context.value(for: "fov")?.angleValue,
                     width: context.value(for: "width")?.doubleValue,

ShapeScriptTests/GeometryTests.swift

@@ -25,9 +25,9 @@ class GeometryTests: XCTestCase {
         )
         let camera = Geometry(
             type: .camera(Camera(
-                hasPosition: false,
-                hasOrientation: false,
-                hasScale: false
+                position: nil,
+                orientation: nil,
+                scale: nil
             )),
             name: nil,
             transform: Transform(

Viewer/Camera.swift

@@ -36,13 +36,6 @@ struct Camera {
 extension Camera: Equatable {
     static let `default` = Self(type: .front)
 
-    static func == (lhs: Camera, rhs: Camera) -> Bool {
-        lhs.type == rhs.type &&
-            lhs.name == rhs.name &&
-            lhs.settings == rhs.settings &&
-            lhs.geometry?.transform == rhs.geometry?.transform
-    }
-
     init(type: CameraType) {
         self.type = type
     }
@@ -73,15 +66,15 @@ extension Camera: Equatable {
     }
 
     var hasPosition: Bool {
-        settings?.hasPosition ?? false
+        settings?.position != nil
     }
 
     var hasOrientation: Bool {
-        settings?.hasOrientation ?? false
+        settings?.orientation != nil
     }
 
     var hasScale: Bool {
-        settings?.hasScale ?? false
+        settings?.scale != nil
     }
 
     var background: MaterialProperty? {

Viewer/Document+View.swift

@@ -164,7 +164,9 @@ extension Document {
             }
             if !oldCameras.isEmpty {
                 var didUpdateCamera = false
-                for (old, new) in zip(oldCameras, cameras) where old != new {
+                for (old, new) in zip(oldCameras, cameras)
+                    where old.type != new.type || old.settings != new.settings
+                {
                     camera = new
                     didUpdateCamera = true
                     break