kriakiku · Nov 8, 2026
@@ -6,6 +6,10 @@ All notable changes to OpenLens are documented here. The format follows
 
 ## [Unreleased]
 
+### Added
+
+- A **Rotate 180°** toggle for cameras mounted upside down, saved per scene.
+
 ## [0.4.6] - 2026-09-24
 
 ### Fixed

@@ -60,7 +60,7 @@ want the product rather than the source. See
   with real pixels — no upscaling. The inspector shows how far that reaches
   ("Stays sharp up to"), and the badge on the picture says `soft` once you pass
   it.
-- **Scenes are the presets.** Camera, zoom, mirror and overlay are saved into
+- **Scenes are the presets.** Camera, zoom, mirror, rotation and overlay are saved into
   the selected scene as you change them — there is no save button. Duplicate
   snapshots the current look, and **⌃⌥1…⌃⌥9** switch between scenes system-wide,
   so it works while you are in a call.

@@ -254,6 +254,7 @@ final class AppModel: ObservableObject {
         pipeline?.update {
             $0.target = scene.crop
             $0.mirror = scene.mirrored
+            $0.rotate180 = scene.rotated180
             $0.overlayEnabled = scene.overlayEnabled
             $0.overlayRect = scene.overlayRect
             $0.overlayOpacity = scene.overlayOpacity
@@ -346,6 +347,12 @@ final class AppModel: ObservableObject {
         pipeline?.update { $0.mirror = mirrored }
     }
 
+    func setRotated180(_ rotated: Bool) {
+        scenes.mutateSelected { $0.rotated180 = rotated }
+        scenes.save()
+        pipeline?.update { $0.rotate180 = rotated }
+    }
+
     // MARK: - Zoom
 
     func zoom(to zoom: CGFloat, anchor: CGPoint) {

@@ -72,6 +72,8 @@ struct CameraScene: Identifiable, Codable, Equatable {
     /// read as "does not drive the lights", not as "wants them all off".
     private var storedLighting: SceneLighting?
 
+    private var storedRotated180: Bool?
+
     var adjustments: ImageAdjustments {
         get { storedAdjustments ?? .neutral }
         set { storedAdjustments = newValue }
@@ -82,11 +84,17 @@ struct CameraScene: Identifiable, Codable, Equatable {
         set { storedLighting = newValue }
     }
 
+    var rotated180: Bool {
+        get { storedRotated180 ?? false }
+        set { storedRotated180 = newValue }
+    }
+
     private enum CodingKeys: String, CodingKey {
         case id, name, deviceID, deviceName, crop, mirrored, quality
         case overlayEnabled, overlayRect, overlayOpacity
         case storedAdjustments = "adjustments"
         case storedLighting = "lighting"
+        case storedRotated180 = "rotated180"
     }
 
     /// Spelled out because the private stored property above would otherwise
@@ -98,6 +106,7 @@ struct CameraScene: Identifiable, Codable, Equatable {
         deviceName: String,
         crop: CropState = .identity,
         mirrored: Bool = false,
+        rotated180: Bool = false,
         quality: CaptureQuality = .losslessZoom,
         overlayEnabled: Bool = false,
         overlayRect: CGRect = CGRect(x: 0.72, y: 0.72, width: 0.24, height: 0.24),
@@ -117,6 +126,7 @@ struct CameraScene: Identifiable, Codable, Equatable {
         self.overlayOpacity = overlayOpacity
         self.storedAdjustments = adjustments
         self.storedLighting = lighting
+        self.storedRotated180 = rotated180
     }
 }
 

@@ -8,6 +8,7 @@ import QuartzCore
 struct FrameSettings {
     var target: CropState = .identity
     var mirror = false
+    var rotate180 = false
     var overlayEnabled = false
     var overlayRect = CGRect(x: 0.72, y: 0.72, width: 0.24, height: 0.24)
     var overlayOpacity: Double = 1
@@ -152,6 +153,7 @@ final class FramePipeline: NSObject, @unchecked Sendable {
                 outputAspect: CGFloat(OpenLensOutput.aspectRatio)
             ),
             mirror: snapshot.mirror,
+            rotate180: snapshot.rotate180,
             overlay: frameOverlay,
             adjustments: snapshot.adjustments
         )

@@ -9,6 +9,7 @@ struct RenderUniforms {
     float  overlayOpacity;
     // 1 when the source should be mirrored horizontally.
     float  mirror;
+    float  rotate180;
     // Luma offset/scale for video-range vs full-range YCbCr.
     float  lumaOffset;
     float  lumaScale;
@@ -58,6 +59,9 @@ vertex VertexOut openlens_vertex(uint vertexID [[vertex_id]],
     // The crop is applied here, in the vertex stage: zooming costs nothing at
     // runtime because it is only a remap of texture coordinates.
     out.sourceCoord = u.cropRect.xy + cropUV * u.cropRect.zw;
+    if (u.rotate180 > 0.5) {
+        out.sourceCoord = 1.0 - out.sourceCoord;
+    }
     return out;
 }
 

@@ -10,6 +10,7 @@ struct RenderUniforms {
     var overlayRect: SIMD4<Float>
     var overlayOpacity: Float
     var mirror: Float
+    var rotate180: Float
     var lumaOffset: Float
     var lumaScale: Float
     var chromaOffset: Float
@@ -147,6 +148,7 @@ final class VideoRenderer {
         var pixelBuffer: CVPixelBuffer
         var crop: CGRect
         var mirror: Bool
+        var rotate180 = false
         var overlay: OverlayTexture?
         var adjustments: ImageAdjustments = .neutral
     }
@@ -330,6 +332,7 @@ final class VideoRenderer {
             } ?? SIMD4<Float>(0, 0, 0, 0),
             overlayOpacity: Float(frame.overlay?.opacity ?? 0),
             mirror: frame.mirror ? 1 : 0,
+            rotate180: frame.rotate180 ? 1 : 0,
             lumaOffset: isFullRange ? 0.0 : 16.0 / 255.0,
             lumaScale: isFullRange ? 1.0 : 255.0 / 219.0,
             chromaOffset: 128.0 / 255.0,

@@ -73,6 +73,7 @@ struct InspectorView: View {
                 }
 
                 Toggle("Mirror", isOn: mirrorBinding)
+                Toggle("Rotate 180°", isOn: rotated180Binding)
 
                 HStack {
                     Button("Duplicate") { model.duplicateSelectedScene() }
@@ -475,6 +476,13 @@ struct InspectorView: View {
         )
     }
 
+    private var rotated180Binding: Binding<Bool> {
+        Binding(
+            get: { scenes.selectedScene?.rotated180 ?? false },
+            set: { model.setRotated180($0) }
+        )
+    }
+
     private var overlayEnabledBinding: Binding<Bool> {
         Binding(
             get: { scenes.selectedScene?.overlayEnabled ?? false },

@@ -31,6 +31,7 @@ final class CameraSceneCodingTests: XCTestCase {
         XCTAssertEqual(scene.name, "Desk")
         XCTAssertEqual(scene.crop.zoom, 1.4, accuracy: 1e-9)
         XCTAssertTrue(scene.mirrored)
+        XCTAssertFalse(scene.rotated180)
         // The missing key must read back as neutral rather than throwing.
         XCTAssertEqual(scene.adjustments, .neutral)
         // And the scene must read as "leaves the lights alone" rather than as
@@ -103,6 +104,7 @@ final class CameraSceneCodingTests: XCTestCase {
             deviceName: "Cam Link 4K",
             crop: CropState(center: CGPoint(x: 0.4, y: 0.6), zoom: 1.8),
             mirrored: true,
+            rotated180: true,
             quality: .matchOutput,
             overlayEnabled: true,
             overlayRect: CGRect(x: 0.1, y: 0.2, width: 0.3, height: 0.4),
@@ -135,7 +137,7 @@ final class CameraSceneCodingTests: XCTestCase {
             [
                 "id", "name", "deviceID", "deviceName", "crop", "mirrored",
                 "quality", "overlayEnabled", "overlayRect", "overlayOpacity",
-                "adjustments", "lighting",
+                "adjustments", "lighting", "rotated180",
             ],
             "A scene property was added or removed. Check that it is listed in "
                 + "CodingKeys and in the hand-written initialiser, and that "

@@ -19,7 +19,7 @@ final class VideoRendererTests: XCTestCase {
     // MARK: - Fixtures
 
     /// A 1280x720 BGRA frame: red on the left half, blue on the right half.
-    private func makeSourceBuffer() throws -> CVPixelBuffer {
+    private func makeSourceBuffer(greenBottomHalf: Bool = false) throws -> CVPixelBuffer {
         let width = 1280
         let height = 720
         var buffer: CVPixelBuffer?
@@ -49,9 +49,10 @@ final class VideoRendererTests: XCTestCase {
             for x in 0..<width {
                 let pixel = row.advanced(by: x * 4)
                 let isLeft = x < width / 2
-                pixel[0] = isLeft ? 0 : 255  // B
-                pixel[1] = 0  // G
-                pixel[2] = isLeft ? 255 : 0  // R
+                let isGreen = greenBottomHalf && y >= height / 2
+                pixel[0] = !isGreen && !isLeft ? 255 : 0  // B
+                pixel[1] = isGreen ? 255 : 0  // G
+                pixel[2] = !isGreen && isLeft ? 255 : 0  // R
                 pixel[3] = 255
             }
         }
@@ -207,6 +208,37 @@ final class VideoRendererTests: XCTestCase {
         assertDominant(\.x, try sample(output, atX: 0.9, y: 0.5))
     }
 
+    func testRotate180TurnsTheImageUpsideDown() throws {
+        let output = try render(
+            VideoRenderer.Frame(
+                pixelBuffer: try makeSourceBuffer(greenBottomHalf: true),
+                crop: CGRect(x: 0, y: 0, width: 1, height: 1),
+                mirror: false,
+                rotate180: true,
+                overlay: nil
+            )
+        )
+        assertDominant(\.y, try sample(output, atX: 0.1, y: 0.25))
+        assertDominant(\.y, try sample(output, atX: 0.9, y: 0.25))
+        assertDominant(\.z, try sample(output, atX: 0.1, y: 0.75))
+        assertDominant(\.x, try sample(output, atX: 0.9, y: 0.75))
+    }
+
+    func testCropAppliesToTheRotatedImage() throws {
+        let output = try render(
+            VideoRenderer.Frame(
+                pixelBuffer: try makeSourceBuffer(),
+                crop: CGRect(x: 0, y: 0, width: 0.5, height: 1),
+                mirror: false,
+                rotate180: true,
+                overlay: nil
+            )
+        )
+        for x in [0.02, 0.5, 0.98] {
+            assertDominant(\.z, try sample(output, atX: x, y: 0.5))
+        }
+    }
+
     func testOverlayIsCompositedOverTheLeftHalfOfTheOutput() throws {
         let output = try render(
             VideoRenderer.Frame(