android: rotate bar icons/text + OSD labels by physical grip angle (accelerometer), image region stays glued

android/app/src/main/kotlin/com/mag160c/thermal/ui/AppRoot.kt

@@ -12,13 +12,17 @@ import androidx.compose.material3.NavigationBarItem
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.layout.onSizeChanged
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.unit.dp
 import com.mag160c.thermal.R
@@ -38,12 +42,20 @@ private val TABS = listOf(
 /**
  * App shell.  The activity is portrait-locked, so the bottom navigation bar
  * is glued to the phone's portrait bottom edge at all times (its absolute
- * position never moves, however the phone is physically held).  Tab content
+ * position never moves, however the phone is physically held).  Bar content
- * lives in a stable slot.
+ * (icons/text) is pre-rotated by the physical device orientation so it stays
+ * readable in any grip.  Tab content lives in a stable slot.
  */
 @Composable
 fun AppRoot() {
     var tab by rememberSaveable { mutableStateOf(0) }
+    val phi by DeviceOrientation.deg.collectAsState()
+    val ctx = LocalContext.current
+
+    DisposableEffect(Unit) {
+        DeviceOrientation.start(ctx)
+        onDispose { DeviceOrientation.stop() }
+    }
 
     Box(modifier = Modifier.fillMaxSize()) {
         when (tab) {
@@ -71,6 +83,8 @@ fun AppRoot() {
                     NavigationBarItem(
                         selected = tab == i,
                         onClick = { tab = i },
+                        // pre-rotate so the item is upright in the current grip
+                        modifier = Modifier.graphicsLayer { rotationZ = -phi.toFloat() },
                         icon = { Icon(painterResource(t.icon), null) },
                         label = { Text(t.label) },
                     )

android/app/src/main/kotlin/com/mag160c/thermal/ui/DeviceOrientation.kt

@@ -0,0 +1,59 @@
+package com.mag160c.thermal.ui
+
+import android.content.Context
+import android.hardware.Sensor
+import android.hardware.SensorEvent
+import android.hardware.SensorEventListener
+import android.hardware.SensorManager
+import kotlin.math.abs
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * Physical orientation of the phone relative to its portrait grip, from the
+ * accelerometer.  [deg] is the CLOCKWISE rotation of the device as seen by
+ * the user: 0 = upright portrait, 90 = turned clockwise (portrait top edge
+ * points to the user's right, gravity along +X device), 180 = upside down,
+ * 270 = turned counter-clockwise.
+ *
+ * The activity is portrait-locked (composition glued to the phone frame, so
+ * the thermal image region always matches the lens direction).  UI layers use
+ * [deg] to pre-rotate their icons/text by -deg so labels stay readable in
+ * whatever grip the phone is currently held.
+ */
+object DeviceOrientation : SensorEventListener {
+    private val _deg = MutableStateFlow(0)
+
+    /** Physical CW rotation of the phone relative to the portrait grip: 0/90/180/270. */
+    val deg: StateFlow<Int> = _deg
+
+    private var sm: SensorManager? = null
+
+    fun start(context: Context) {
+        if (sm != null) return
+        val m = context.getSystemService(Context.SENSOR_SERVICE) as SensorManager
+        val sensor = m.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) ?: return
+        sm = m
+        m.registerListener(this, sensor, SensorManager.SENSOR_DELAY_UI)
+    }
+
+    fun stop() {
+        sm?.unregisterListener(this)
+        sm = null
+    }
+
+    override fun onSensorChanged(event: SensorEvent) {
+        val gx = event.values[0]
+        val gy = event.values[1]
+        // hysteresis: only switch pose when the dominant axis clearly wins,
+        // so ~45 deg in-between holds keep the previous reading
+        val next = when {
+            abs(gx) > abs(gy) + 2.5f -> if (gx > 0) 90 else 270
+            abs(gy) > abs(gx) + 2.5f -> if (gy < 0) 0 else 180
+            else -> _deg.value
+        }
+        if (next != _deg.value) _deg.value = next
+    }
+
+    override fun onAccuracyChanged(sensor: Sensor?, accuracy: Int) = Unit
+}

android/app/src/main/kotlin/com/mag160c/thermal/ui/live/LiveRenderer.kt

@@ -16,8 +16,10 @@ import android.view.SurfaceView
  * CW (3:4 vertical) into a fixed fitted rect inside the available area
  * (full screen minus the control top bar and the bottom navigation bar).
  * The image region does NOT move or rotate however the phone is physically
- * held, so the on-screen area always matches the thermal lens direction;
+ * held, so the on-screen area always matches the thermal lens direction.
- * OSD text stays screen-horizontal so the labels are always readable.
+ * OSD text (center temp / probe labels / color-bar numbers) is pre-rotated
+ * by the accelerometer-derived grip angle so labels stay readable in any
+ * grip; marker dots and the color-bar strip stay glued to the image.
  */
 class LiveRenderer(
     private val surfaceView: SurfaceView,
@@ -40,6 +42,10 @@ class LiveRenderer(
     }
     private val viewport = android.graphics.RectF()
 
+    /** OSD text compensation: pre-rotation so labels are upright in the current grip. */
+    private val textRot: Float
+        get() = -com.mag160c.thermal.ui.DeviceOrientation.deg.value.toFloat()
+
     fun attach() {
         surfaceView.holder.addCallback(this)
     }
@@ -147,7 +153,11 @@ class LiveRenderer(
         if (tx + tw + pad > viewport.right) tx = cx - 14f * density - tw
         if (ty > viewport.bottom - 4f * density) ty = cy - 10f * density
         if (ty < viewport.top + textPaint.textSize) ty = cy + textPaint.textSize + 4f * density
+        // pivot around the marker anchor: the label stays attached while upright
+        canvas.save()
+        canvas.rotate(textRot, cx, cy)
         canvas.drawText(text, tx, ty, textPaint)
+        canvas.restore()
     }
 
     private fun drawColorBar(canvas: Canvas, state: LiveViewModel.LiveState) {
@@ -169,8 +179,16 @@ class LiveRenderer(
         textPaint.color = Color.WHITE
         val maxT = "%.1f".format(state.maxTempC)
         val minT = "%.1f".format(state.minTempC)
-        canvas.drawText(maxT, x + barW / 2f - textPaint.measureText(maxT) / 2, y0 - 8f * density, textPaint)
+        val labelX = x + barW / 2f - textPaint.measureText(maxT) / 2
-        canvas.drawText(minT, x + barW / 2f - textPaint.measureText(minT) / 2, y0 + barH + textPaint.textSize, textPaint)
+        val labelMaxX = x + barW / 2f - textPaint.measureText(minT) / 2
+        canvas.save()
+        canvas.rotate(textRot, x + barW / 2f, y0 - 8f * density)
+        canvas.drawText(maxT, labelX, y0 - 8f * density, textPaint)
+        canvas.restore()
+        canvas.save()
+        canvas.rotate(textRot, x + barW / 2f, y0 + barH + textPaint.textSize)
+        canvas.drawText(minT, labelMaxX, y0 + barH + textPaint.textSize, textPaint)
+        canvas.restore()
     }
 
     private fun drawOsd(canvas: Canvas, state: LiveViewModel.LiveState) {
@@ -178,7 +196,10 @@ class LiveRenderer(
         val ox = viewport.left + 12f * density
         val oy = viewport.top + textPaint.textSize + 10f * density
         state.centerTempC?.let {
+            canvas.save()
+            canvas.rotate(textRot, ox, oy)
             canvas.drawText("中心 %.1f℃".format(it), ox, oy, textPaint)
+            canvas.restore()
         }
         if (state.maxTraceOn) {
             drawTempMarker(canvas, state.maxPos % 160, state.maxPos / 160, state.maxTempC, "高")

android/app/src/main/kotlin/com/mag160c/thermal/ui/live/LiveScreen.kt

@@ -31,6 +31,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.layout.onSizeChanged
 import androidx.compose.ui.platform.LocalContext
@@ -48,12 +49,15 @@ import android.view.SurfaceView
  * The activity is portrait-locked, so the whole composition (top bar /
  * image region / bottom bar) is glued to the phone's portrait frame and
  * never moves or rotates, however the phone is physically held — the on-
- * screen area always matches the thermal lens direction.
+ * screen area always matches the thermal lens direction.  The bars' icons
+ * and text are pre-rotated by the physical grip angle (DeviceOrientation)
+ * so they stay readable in any grip.
  */
 @Composable
 fun LiveScreen(vm: LiveViewModel = viewModel()) {
     val state by vm.state.collectAsState()
     val context = LocalContext.current
+    val phi by com.mag160c.thermal.ui.DeviceOrientation.deg.collectAsState()
     var showPalette by remember { mutableStateOf(false) }
 
     LaunchedEffect(Unit) {
@@ -84,7 +88,10 @@ fun LiveScreen(vm: LiveViewModel = viewModel()) {
         if (!state.connected) {
             Text(
                 text = statusText(state),
-                modifier = Modifier.align(Alignment.Center).padding(16.dp),
+                modifier = Modifier
+                    .align(Alignment.Center)
+                    .graphicsLayer { rotationZ = -phi.toFloat() }
+                    .padding(16.dp),
             )
         }
 
@@ -107,17 +114,17 @@ fun LiveScreen(vm: LiveViewModel = viewModel()) {
                     .padding(vertical = 4.dp),
                 verticalAlignment = Alignment.CenterVertically,
             ) {
-                Box(modifier = Modifier.weight(1f), contentAlignment = Alignment.Center) {
+                Box(modifier = Modifier.weight(1f).graphicsLayer { rotationZ = -phi.toFloat() }, contentAlignment = Alignment.Center) {
                     IconButton(onClick = { vm.triggerFfc() }) {
                         Icon(painterResource(R.drawable.ic_ffc), "FFC 快门校正")
                     }
                 }
-                Box(modifier = Modifier.weight(1f), contentAlignment = Alignment.Center) {
+                Box(modifier = Modifier.weight(1f).graphicsLayer { rotationZ = -phi.toFloat() }, contentAlignment = Alignment.Center) {
                     IconButton(onClick = { vm.setZoom(vm.state.value.zoom % 4 + 1) }) {
                         Icon(painterResource(R.drawable.ic_zoom), "数码变倍 x${state.zoom}")
                     }
                 }
-                Box(modifier = Modifier.weight(1f), contentAlignment = Alignment.Center) {
+                Box(modifier = Modifier.weight(1f).graphicsLayer { rotationZ = -phi.toFloat() }, contentAlignment = Alignment.Center) {
                     Text(
                         text = if (state.maxTraceOn) "追踪·开" else "追踪",
                         style = MaterialTheme.typography.labelMedium,
@@ -126,22 +133,22 @@ fun LiveScreen(vm: LiveViewModel = viewModel()) {
                         modifier = Modifier.clickable { vm.toggleMaxTrace() },
                     )
                 }
-                Box(modifier = Modifier.weight(1f), contentAlignment = Alignment.Center) {
+                Box(modifier = Modifier.weight(1f).graphicsLayer { rotationZ = -phi.toFloat() }, contentAlignment = Alignment.Center) {
                     IconButton(onClick = { showPalette = true }) {
                         Icon(painterResource(R.drawable.ic_palette), "调色板")
                     }
                 }
-                Box(modifier = Modifier.weight(1f), contentAlignment = Alignment.Center) {
+                Box(modifier = Modifier.weight(1f).graphicsLayer { rotationZ = -phi.toFloat() }, contentAlignment = Alignment.Center) {
                     IconButton(onClick = { vm.capturePhoto(context) }) {
                         Icon(painterResource(R.drawable.ic_camera), "拍照")
                     }
                 }
-                Box(modifier = Modifier.weight(1f), contentAlignment = Alignment.Center) {
+                Box(modifier = Modifier.weight(1f).graphicsLayer { rotationZ = -phi.toFloat() }, contentAlignment = Alignment.Center) {
                     IconButton(onClick = { vm.toggleRecording(context) }) {
                         Icon(painterResource(R.drawable.ic_record), "录像")
                     }
                 }
-                Box(modifier = Modifier.weight(1f), contentAlignment = Alignment.Center) {
+                Box(modifier = Modifier.weight(1f).graphicsLayer { rotationZ = -phi.toFloat() }, contentAlignment = Alignment.Center) {
                     Text(
                         text = Palettes.NAMES[state.paletteIndex],
                         style = MaterialTheme.typography.labelMedium,

docs/android_app/HANDOFF_DEVELOPMENT.md

@@ -51,6 +51,7 @@
 android/app/src/main/kotlin/com/mag160c/thermal/
 ├─ MainActivity.kt           启动，enableEdgeToEdge + 隐藏状态栏（沉浸）
 ├─ ui/AppRoot.kt             App壳：底部导航（实时/相册/分析/设置）恒贴竖屏底边（Activity 竖屏锁定）
+├─ ui/DeviceOrientation.kt   加速度计→手机物理朝向（条栏/OSD 文字补偿旋转用）
 ├─ ui/UiInsets.kt            单例：底部导航高度 px（渲染器用它留白）
 ├─ ui/theme/Theme.kt         M3 动态取色（Android12+）
 ├─ ui/live/                  ★实时画面（最核心）
@@ -105,6 +106,11 @@ res/drawable/*.xml          自绘矢量图标（双弧圆等可靠几何图形
   永不旋转。顶栏、热像区域、底栏的**绝对位置**永远贴着手机竖屏的物理顶边（挖孔侧）、
   中间、物理底边；手机怎么物理旋转，构图都不动（用户明确要求：屏显方向必须始终
   与热像镜头实际方向对应，横屏后显示区域跟着屏幕转是错的）。**不要改回 fullSensor。**
+- **图标/文字按物理持机朝向补偿旋转**（第六轮定稿）：`ui/DeviceOrientation.kt` 用
+  加速度计得出手机相对竖屏的顺时针物理转角 φ（0/90/180/270，带滞回；竖屏锁定下
+  Display.rotation 恒 0 不可用）。顶栏/底部导航条目 `graphicsLayer rotationZ=-φ`
+  原位预旋转；渲染器 OSD 文字 `canvas.rotate(-φ)` 绕锚点旋转（标记圆点、色标条
+  几何仍钉死在图像上）。对话框与其他页签暂不补偿。
 - **图像恒 90°CW 绘制为 3:4 竖向**，填满可用区域（顶栏下~底导航上）。
 - **文字/图标恒屏幕水平**（可读）；标记文字位置自动跟随（probeToScreen 固定 90° 映射：
   `fx=1-sy/120, fy=sx/160`）。

docs/android_app/session_state.md

@@ -138,6 +138,22 @@
 - [x] 单元测试全过；APK 已更新 build-artifacts/mag160c-app-debug.apk。
 - 注：不要再改回 fullSensor/sensor 横屏；横竖屏适配类需求一律以"竖屏构图恒定"为准。
 
+## 用户反馈修复 第六轮（2026-09-07，横屏持机图标文字可读）
+
+- [x] **用户反馈**：竖屏锁定后，横过来拿手机时顶栏/底栏里的图标和文字不旋转（侧着）。
+      约定补全：**构图钉死竖屏框架不变**（条栏绝对位置+热像区域不动），但条栏内容
+      （图标+文字）与 OSD 文字要按**物理持机朝向**补偿旋转，保持可读。
+- [x] 新增 `ui/DeviceOrientation.kt`：加速度计→手机相对竖屏的顺时针物理转角
+      φ∈{0,90,180,270}（主轴判定+2.5m/s² 滞回；竖屏锁定下 Display.rotation 恒 0 不可用）。
+- [x] 顶栏 7 控制项/底部导航 4 项：`graphicsLayer rotationZ=-φ` 原位预旋转（布局不动）。
+- [x] 渲染器 OSD 文字（中心温/探针标注/色标最高最低数字）`canvas.rotate(-φ)` 绕锚点
+      旋转；标记圆点、色标条几何仍钉死在图像上。
+- [x] 模拟器实测（`adb emu sensor set acceleration` 驱动 4 姿态）：四姿态下热像区域
+      完全一致，图标/文字按姿态正确补偿（analysis/preview/preview_pose*_v6.png）；
+      姿态复位 0° 后输出与第五轮逐字节一致（MD5 相同）。
+- [x] 单元测试全过；APK 已更新。
+- 注：对话框（调色板等）与其他页签内容未做补偿旋转（保持竖屏可读），如需再加。
+
 ## 待办
 
 - 真机USB实测（温度绝对值标定、FFC/录像/MDT保存端到端）