CLAUDE.md

@@ -86,21 +86,6 @@ Bitmaps emitted to `StateFlow`s are **never eagerly recycled** immediately after
 - Error/success dismiss indicators use cancellable `Job` tracking to prevent race conditions
 - `writeExifToUri()` returns boolean and logs at ERROR level on failure
 
-### Orientation policy (do not change without asking)
-
-- Activity is `screenOrientation="portrait"` in the manifest. The GL surface and Compose layout therefore never rotate.
-- The camera passthrough uses a fixed 90° texcoord rotation (`texCoordsBack`/`texCoordsFront`). There is no `setTargetRotation`/`setDisplayRotation`/`getTransformMatrix`-based rotation tracking — past attempts (v1.1.6 through v1.1.13) all introduced subtle bugs and were reverted.
-- The camera image lives in the device's portrait frame and visually follows the phone as it tilts. Per-orientation correctness comes from the EXIF orientation tag written at capture (`OrientationDetector.degreesToExifOrientation(rotationToDegrees(deviceRotation), isFrontCamera)`), not from rotating the bitmap.
-- `OrientationEventListener` (`viewModel.currentRotation`) is for EXIF only. It is **not** the same as `Display.rotation`: it fires at the 45° tilt threshold while the activity rotates later, so it must not drive anything that has to stay in sync with the GL surface.
-- `SurfaceTexture.getTransformMatrix()` with a custom `SurfaceProvider` does not change on `Preview.targetRotation` updates; rebinding doesn't reliably help either. Don't go down that road again.
-
-### Local Android testing
-
-- AVD: `tilfluktsrom` (Pixel 6, API 35, Google APIs) at `~/.android/avd/`. Boot with `emulator -avd tilfluktsrom -no-snapshot-save -gpu swiftshader_indirect -no-audio`.
-- `adb -s emulator-5554 emu rotate` cycles `ROTATION_0 → 3 → 2 → 1 → 0` (decrements by 90°), not the other way.
-- The default virtual scene is too rotationally symmetric to verify which way is "up". For orientation testing, pass `-virtualscene-poster wall=/path/to/marker.png` and ensure the scene camera faces the wall, or just don't trust emulator screenshots as proof of correct orientation.
-- Camera bitmaps captured at startup tend to look black for a few seconds while CameraX rebinds. Wait ≥10 s after `am start` before screenshotting.
-
 ## Permissions
 
 | Permission | Purpose | Notes |

app/src/main/AndroidManifest.xml

@@ -31,7 +31,7 @@
         <activity
             android:name=".MainActivity"
             android:exported="true"
-            android:screenOrientation="portrait"
+            android:screenOrientation="fullSensor"
             android:configChanges="orientation|screenSize|screenLayout|keyboardHidden"
             android:windowSoftInputMode="adjustNothing"
             android:theme="@style/Theme.TiltShiftCamera">

app/src/main/java/no/naiv/tiltshift/camera/CameraManager.kt

@@ -2,8 +2,10 @@ package no.naiv.tiltshift.camera
 
 import android.content.Context
 import android.graphics.SurfaceTexture
+import android.hardware.display.DisplayManager
 import android.util.Log
 import android.util.Size
+import android.view.Display
 import android.view.Surface
 import androidx.camera.core.Camera
 import androidx.camera.core.CameraSelector
@@ -70,6 +72,14 @@ class CameraManager(private val context: Context) {
     /** Weak reference to avoid preventing Activity GC across config changes. */
     private var lifecycleOwnerRef: WeakReference<LifecycleOwner>? = null
 
+    /**
+     * Target rotation passed to CameraX use cases. Drives the SurfaceTexture
+     * transform matrix and the rotation metadata on captured images.
+     * Initialized to the display rotation when the camera binds; updated by
+     * [setTargetRotation] when the device orientation changes.
+     */
+    private var targetRotation: Int = Surface.ROTATION_0
+
     /**
      * Starts the camera with the given lifecycle owner.
      * The surfaceTextureProvider should return the SurfaceTexture from the GL renderer.
@@ -80,6 +90,13 @@ class CameraManager(private val context: Context) {
     ) {
         this.surfaceTextureProvider = surfaceTextureProvider
         this.lifecycleOwnerRef = WeakReference(lifecycleOwner)
+        // Capture initial display rotation so the very first frame is oriented correctly,
+        // before the OrientationEventListener has had a chance to fire.
+        // Note: Context.getDisplay() throws on Application contexts; DisplayManager works
+        // for any context type and returns the default display.
+        targetRotation = (context.getSystemService(Context.DISPLAY_SERVICE) as? DisplayManager)
+            ?.getDisplay(Display.DEFAULT_DISPLAY)?.rotation
+            ?: Surface.ROTATION_0
 
         val cameraProviderFuture = ProcessCameraProvider.getInstance(context)
         cameraProviderFuture.addListener({
@@ -110,11 +127,13 @@ class CameraManager(private val context: Context) {
 
         preview = Preview.Builder()
             .setResolutionSelector(resolutionSelector)
+            .setTargetRotation(targetRotation)
             .build()
 
         // Image capture use case
         val captureBuilder = ImageCapture.Builder()
             .setCaptureMode(ImageCapture.CAPTURE_MODE_MAXIMIZE_QUALITY)
+            .setTargetRotation(targetRotation)
 
         imageCapture = captureBuilder.build()
 
@@ -173,6 +192,23 @@ class CameraManager(private val context: Context) {
         }
     }
 
+    /**
+     * Updates the target rotation for Preview and ImageCapture use cases.
+     *
+     * Rebinds the use cases so CameraX issues a fresh SurfaceRequest with a
+     * resolution matching the new rotation and a corresponding texture transform
+     * matrix. Calling `preview.targetRotation = rotation` alone is insufficient
+     * for a custom SurfaceProvider — the new rotation only takes effect on
+     * subsequently bound streams, leaving the live SurfaceTexture matrix and
+     * buffer size stale (which made the preview appear locked to the original
+     * portrait orientation when the device was rotated to landscape).
+     */
+    fun setTargetRotation(rotation: Int) {
+        if (targetRotation == rotation) return
+        targetRotation = rotation
+        lifecycleOwnerRef?.get()?.let { bindCameraUseCases(it) }
+    }
+
     /**
      * Sets the zoom ratio. Updates UI state immediately so that rapid pinch-to-zoom
      * gestures accumulate correctly (each frame uses the latest ratio as its base).

app/src/main/java/no/naiv/tiltshift/camera/ImageCaptureHandler.kt

@@ -24,7 +24,6 @@ import kotlin.coroutines.resume
 import kotlin.math.cos
 import kotlin.math.sin
 import kotlin.math.sqrt
-import no.naiv.tiltshift.util.OrientationDetector
 
 /**
  * Handles capturing photos with the tilt-shift effect applied.
@@ -122,19 +121,10 @@ class ImageCaptureHandler(
                 var thumbnail: Bitmap? = null
                 try {
                     thumbnail = createThumbnail(captureResult.processed)
-                    // Camera bitmap is in the device's portrait frame (CameraX
-                    // rotated the sensor 90° because the activity is locked to
-                    // portrait). Tag the EXIF with the user's physical tilt
-                    // when they pressed the shutter so viewers display the
-                    // photo right-side-up regardless of how the phone was held.
-                    val exifOrientation = OrientationDetector.degreesToExifOrientation(
-                        OrientationDetector.rotationToDegrees(deviceRotation),
-                        isFrontCamera
-                    )
                     val result = photoSaver.saveBitmapPair(
                         original = captureResult.original,
                         processed = captureResult.processed,
-                        orientation = exifOrientation,
+                        orientation = ExifInterface.ORIENTATION_NORMAL,
                         location = location
                     )
                     if (result is SaveResult.Success) {

app/src/main/java/no/naiv/tiltshift/effect/TiltShiftRenderer.kt

@@ -6,6 +6,7 @@ import android.opengl.GLES11Ext
 import android.opengl.GLES20
 import android.opengl.GLSurfaceView
 import android.util.Log
+import android.view.Surface
 import java.nio.ByteBuffer
 import java.nio.ByteOrder
 import java.nio.FloatBuffer
@@ -38,9 +39,8 @@ class TiltShiftRenderer(
     private var surfaceTexture: SurfaceTexture? = null
     private var cameraTextureId: Int = 0
 
-    // Camera quad: crop-to-fill vertices + rotated texcoords (pass 1 only)
+    // Camera quad: crop-to-fill vertices, standard texcoords (rotation comes from texMatrix)
     private lateinit var cameraVertexBuffer: FloatBuffer
-    private lateinit var cameraTexCoordBuffer: FloatBuffer
 
     // Fullscreen quad for blur passes (no crop, standard texcoords)
     private lateinit var fullscreenVertexBuffer: FloatBuffer
@@ -54,6 +54,9 @@ class TiltShiftRenderer(
     private var fboTexA: Int = 0
     private var fboTexB: Int = 0
 
+    // SurfaceTexture transform matrix, refreshed each frame on the GL thread.
+    private val texMatrix = FloatArray(16)
+
     // Current effect parameters (updated from UI thread)
     @Volatile
     var blurParameters: BlurParameters = BlurParameters.DEFAULT
@@ -66,33 +69,14 @@ class TiltShiftRenderer(
     private var cameraWidth: Int = 0
     @Volatile
     private var cameraHeight: Int = 0
+
+    /** Display rotation as a Surface.ROTATION_* constant; affects effective aspect. */
+    @Volatile
+    private var displayRotation: Int = Surface.ROTATION_0
+
     @Volatile
     private var vertexBufferDirty: Boolean = false
 
-    // Texture coordinates rotated 90° for portrait mode (back camera)
-    // (Camera sensors are landscape-oriented, we rotate to portrait)
-    private val texCoordsBack = floatArrayOf(
-        1f, 1f,  // Bottom left of screen  -> bottom right of texture
-        1f, 0f,  // Bottom right of screen -> top right of texture
-        0f, 1f,  // Top left of screen     -> bottom left of texture
-        0f, 0f   // Top right of screen    -> top left of texture
-    )
-
-    // Texture coordinates for front camera (mirrored + rotated)
-    // Front camera needs horizontal mirror for natural selfie view
-    private val texCoordsFront = floatArrayOf(
-        0f, 1f,  // Bottom left of screen
-        0f, 0f,  // Bottom right of screen
-        1f, 1f,  // Top left of screen
-        1f, 0f   // Top right of screen
-    )
-
-    @Volatile
-    private var currentTexCoords = texCoordsBack
-
-    @Volatile
-    private var updateTexCoordBuffer = false
-
     override fun onSurfaceCreated(gl: GL10?, config: EGLConfig?) {
         GLES20.glClearColor(0f, 0f, 0f, 1f)
 
@@ -104,12 +88,8 @@ class TiltShiftRenderer(
         cameraVertexBuffer.put(floatArrayOf(-1f, -1f, 1f, -1f, -1f, 1f, 1f, 1f))
         cameraVertexBuffer.position(0)
 
-        // Camera texcoord buffer (rotated for portrait)
+        // Fullscreen quad for blur passes (standard coords). The same buffer is reused
-        cameraTexCoordBuffer = allocateFloatBuffer(8)
+        // for the camera passthrough texcoords — rotation is applied via uTexMatrix.
-        cameraTexCoordBuffer.put(currentTexCoords)
-        cameraTexCoordBuffer.position(0)
-
-        // Fullscreen quad for blur passes (standard coords)
         fullscreenVertexBuffer = allocateFloatBuffer(8)
         fullscreenVertexBuffer.put(floatArrayOf(-1f, -1f, 1f, -1f, -1f, 1f, 1f, 1f))
         fullscreenVertexBuffer.position(0)
@@ -145,20 +125,17 @@ class TiltShiftRenderer(
     }
 
     override fun onDrawFrame(gl: GL10?) {
-        surfaceTexture?.updateTexImage()
+        val st = surfaceTexture
+        st?.updateTexImage()
+        // Pull the latest sensor-to-display transform; updated by SurfaceTexture each frame
+        // and reflects whatever rotation CameraX requested via Preview.targetRotation.
+        st?.getTransformMatrix(texMatrix)
 
         if (vertexBufferDirty) {
             recomputeVertices()
             vertexBufferDirty = false
         }
 
-        if (updateTexCoordBuffer) {
-            cameraTexCoordBuffer.clear()
-            cameraTexCoordBuffer.put(currentTexCoords)
-            cameraTexCoordBuffer.position(0)
-            updateTexCoordBuffer = false
-        }
-
         val params = blurParameters
 
         // --- Pass 1: Camera → FBO-A (passthrough with crop-to-fill) ---
@@ -169,10 +146,10 @@ class TiltShiftRenderer(
         )
         GLES20.glViewport(0, 0, surfaceWidth, surfaceHeight)
         GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT)
-        shader.usePassthrough(cameraTextureId)
+        shader.usePassthrough(cameraTextureId, texMatrix, isFrontCamera)
         drawQuad(
             shader.passthroughPositionLoc, shader.passthroughTexCoordLoc,
-            cameraVertexBuffer, cameraTexCoordBuffer
+            cameraVertexBuffer, fullscreenTexCoordBuffer
         )
 
         // --- Pass 2: FBO-A → FBO-B (horizontal blur) ---
@@ -203,11 +180,7 @@ class TiltShiftRenderer(
     }
 
     fun setFrontCamera(front: Boolean) {
-        if (isFrontCamera != front) {
+        isFrontCamera = front
-            isFrontCamera = front
-            currentTexCoords = if (front) texCoordsFront else texCoordsBack
-            updateTexCoordBuffer = true
-        }
     }
 
     fun setCameraResolution(width: Int, height: Int) {
@@ -218,6 +191,14 @@ class TiltShiftRenderer(
         }
     }
 
+    /** Updates the display rotation so crop-to-fill picks the right effective aspect. */
+    fun setDisplayRotation(rotation: Int) {
+        if (displayRotation != rotation) {
+            displayRotation = rotation
+            vertexBufferDirty = true
+        }
+    }
+
     fun release() {
         shader.release()
         surfaceTexture?.release()
@@ -254,16 +235,24 @@ class TiltShiftRenderer(
     /**
      * Recomputes camera vertex positions to achieve crop-to-fill.
      *
-     * The camera sensor is landscape; after the 90° rotation applied via texture coordinates,
+     * The camera buffer is the sensor's native landscape resolution. The texMatrix
-     * the effective portrait dimensions are (cameraHeight × cameraWidth). We scale the vertex
+     * rotates it to match the display, so the *effective* displayed dimensions
-     * quad so the camera frame fills the surface without stretching — the GPU clips the overflow.
+     * depend on the display rotation: in portrait the buffer is rotated 90°
+     * (effective width = cameraHeight), in landscape it is unrotated.
+     * We scale the vertex quad so the frame fills the surface without stretching —
+     * the GPU clips the overflow.
      */
     private fun recomputeVertices() {
         var scaleX = 1f
         var scaleY = 1f
 
         if (cameraWidth > 0 && cameraHeight > 0 && surfaceWidth > 0 && surfaceHeight > 0) {
-            val cameraRatio = cameraHeight.toFloat() / cameraWidth
+            val isPortrait = displayRotation == Surface.ROTATION_0 ||
+                displayRotation == Surface.ROTATION_180
+            val effectiveW = if (isPortrait) cameraHeight else cameraWidth
+            val effectiveH = if (isPortrait) cameraWidth else cameraHeight
+
+            val cameraRatio = effectiveW.toFloat() / effectiveH
             val screenRatio = surfaceWidth.toFloat() / surfaceHeight
 
             if (cameraRatio > screenRatio) {

app/src/main/java/no/naiv/tiltshift/effect/TiltShiftShader.kt

@@ -20,6 +20,15 @@ import kotlin.math.sin
  */
 class TiltShiftShader(private val context: Context) {
 
+    private companion object {
+        val IDENTITY_MATRIX = floatArrayOf(
+            1f, 0f, 0f, 0f,
+            0f, 1f, 0f, 0f,
+            0f, 0f, 1f, 0f,
+            0f, 0f, 0f, 1f
+        )
+    }
+
     // --- Passthrough program (camera → FBO) ---
 
     private var passthroughProgramId: Int = 0
@@ -29,6 +38,8 @@ class TiltShiftShader(private val context: Context) {
     var passthroughTexCoordLoc: Int = 0
         private set
     private var passthroughTextureLoc: Int = 0
+    private var passthroughTexMatrixLoc: Int = 0
+    private var passthroughMirrorLoc: Int = 0
 
     // --- Blur program (FBO → FBO/screen) ---
 
@@ -39,6 +50,8 @@ class TiltShiftShader(private val context: Context) {
     var blurTexCoordLoc: Int = 0
         private set
     private var blurTextureLoc: Int = 0
+    private var blurTexMatrixLoc: Int = 0
+    private var blurMirrorLoc: Int = 0
     private var blurModeLoc: Int = 0
     private var blurPositionXLoc: Int = 0
     private var blurPositionYLoc: Int = 0
@@ -68,6 +81,8 @@ class TiltShiftShader(private val context: Context) {
         passthroughPositionLoc = GLES20.glGetAttribLocation(passthroughProgramId, "aPosition")
         passthroughTexCoordLoc = GLES20.glGetAttribLocation(passthroughProgramId, "aTexCoord")
         passthroughTextureLoc = GLES20.glGetUniformLocation(passthroughProgramId, "uTexture")
+        passthroughTexMatrixLoc = GLES20.glGetUniformLocation(passthroughProgramId, "uTexMatrix")
+        passthroughMirrorLoc = GLES20.glGetUniformLocation(passthroughProgramId, "uMirrorX")
 
         // Blur program
         val blurFragSource = loadShaderSource(R.raw.tiltshift_fragment)
@@ -78,6 +93,8 @@ class TiltShiftShader(private val context: Context) {
         blurPositionLoc = GLES20.glGetAttribLocation(blurProgramId, "aPosition")
         blurTexCoordLoc = GLES20.glGetAttribLocation(blurProgramId, "aTexCoord")
         blurTextureLoc = GLES20.glGetUniformLocation(blurProgramId, "uTexture")
+        blurTexMatrixLoc = GLES20.glGetUniformLocation(blurProgramId, "uTexMatrix")
+        blurMirrorLoc = GLES20.glGetUniformLocation(blurProgramId, "uMirrorX")
         blurModeLoc = GLES20.glGetUniformLocation(blurProgramId, "uMode")
         blurPositionXLoc = GLES20.glGetUniformLocation(blurProgramId, "uPositionX")
         blurPositionYLoc = GLES20.glGetUniformLocation(blurProgramId, "uPositionY")
@@ -96,12 +113,19 @@ class TiltShiftShader(private val context: Context) {
 
     /**
      * Activates the passthrough program and binds the camera texture.
+     *
+     * @param cameraTextureId  The OES texture receiving camera frames.
+     * @param texMatrix        4x4 transform from SurfaceTexture.getTransformMatrix() —
+     *                         encodes sensor-to-display rotation and Y-flip.
+     * @param mirrorX          true to horizontally mirror (front camera selfie view).
      */
-    fun usePassthrough(cameraTextureId: Int) {
+    fun usePassthrough(cameraTextureId: Int, texMatrix: FloatArray, mirrorX: Boolean) {
         GLES20.glUseProgram(passthroughProgramId)
         GLES20.glActiveTexture(GLES20.GL_TEXTURE0)
         GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, cameraTextureId)
         GLES20.glUniform1i(passthroughTextureLoc, 0)
+        GLES20.glUniformMatrix4fv(passthroughTexMatrixLoc, 1, false, texMatrix, 0)
+        GLES20.glUniform1f(passthroughMirrorLoc, if (mirrorX) 1f else 0f)
     }
 
     /**
@@ -128,6 +152,10 @@ class TiltShiftShader(private val context: Context) {
         GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, fboTextureId)
         GLES20.glUniform1i(blurTextureLoc, 0)
 
+        // FBO content is already in display orientation — pass identity matrix and no mirror.
+        GLES20.glUniformMatrix4fv(blurTexMatrixLoc, 1, false, IDENTITY_MATRIX, 0)
+        GLES20.glUniform1f(blurMirrorLoc, 0f)
+
         GLES20.glUniform1i(blurModeLoc, if (params.mode == BlurMode.RADIAL) 1 else 0)
         GLES20.glUniform1f(blurPositionXLoc, params.positionX)
         GLES20.glUniform1f(blurPositionYLoc, params.positionY)

app/src/main/java/no/naiv/tiltshift/ui/CameraScreen.kt

@@ -112,6 +112,7 @@ fun CameraScreen(
     val isFrontCamera by viewModel.cameraManager.isFrontCamera.collectAsState()
     val previewResolution by viewModel.cameraManager.previewResolution.collectAsState()
     val cameraError by viewModel.cameraManager.error.collectAsState()
+    val currentRotation by viewModel.currentRotation.collectAsState()
 
     // Gallery picker
     val galleryLauncher = rememberLauncherForActivityResult(
@@ -164,6 +165,13 @@ fun CameraScreen(
         }
     }
 
+    // Forward device rotation to renderer (aspect math) and CameraX (target rotation)
+    LaunchedEffect(currentRotation, renderer) {
+        renderer?.setDisplayRotation(currentRotation)
+        viewModel.cameraManager.setTargetRotation(currentRotation)
+        glSurfaceView?.requestRender()
+    }
+
     // Start camera when surface texture is available
     LaunchedEffect(surfaceTexture) {
         surfaceTexture?.let {

app/src/main/java/no/naiv/tiltshift/ui/ControlPanel.kt

@@ -12,7 +12,10 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.layout.wrapContentHeight
+import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.RestartAlt
 import androidx.compose.material3.Icon
@@ -110,8 +113,10 @@ fun ControlPanel(
     Column(
         modifier = modifier
             .width(200.dp)
+            .wrapContentHeight()
             .clip(RoundedCornerShape(16.dp))
             .background(AppColors.OverlayDarker)
+            .verticalScroll(rememberScrollState())
             .padding(16.dp),
         verticalArrangement = Arrangement.spacedBy(12.dp)
     ) {

app/src/main/res/raw/tiltshift_vertex.glsl

@@ -1,12 +1,22 @@
-// Vertex shader for tilt-shift effect
+// Vertex shader for tilt-shift effect.
-// Passes through position and calculates texture coordinates
+//
+// uTexMatrix: applied to texcoords. For the passthrough pass it carries the
+// SurfaceTexture transform (sensor → display rotation, plus Y-flip). For the
+// blur passes it is identity.
+// uMirrorX: 1.0 to horizontally mirror texcoords (front-camera selfie view),
+// 0.0 otherwise. Applied AFTER uTexMatrix.
 
 attribute vec4 aPosition;
 attribute vec2 aTexCoord;
 
+uniform mat4 uTexMatrix;
+uniform float uMirrorX;
+
 varying vec2 vTexCoord;
 
 void main() {
     gl_Position = aPosition;
-    vTexCoord = aTexCoord;
+    vec2 tc = (uTexMatrix * vec4(aTexCoord, 0.0, 1.0)).xy;
+    if (uMirrorX > 0.5) tc.x = 1.0 - tc.x;
+    vTexCoord = tc;
 }

version.properties

@@ -1,4 +1,4 @@
 versionMajor=1
 versionMinor=1
-versionPatch=15
+versionPatch=8
-versionCode=17
+versionCode=10