feat: Support focus() on Android (#1713)

* feat: Support `focus()` on Android

* perf: Cache RequestBuilder

* Use 30 FPS as default

* feat: Implement focus(x, y)

* fix: Fix ByteBuffer resizing

android/src/main/java/com/mrousavy/camera/CameraSession.kt

@@ -1,17 +1,21 @@
 package com.mrousavy.camera
 
 import android.content.Context
+import android.graphics.Point
 import android.hardware.camera2.CameraCaptureSession
 import android.hardware.camera2.CameraCharacteristics
 import android.hardware.camera2.CameraDevice
 import android.hardware.camera2.CameraManager
+import android.hardware.camera2.CameraMetadata
 import android.hardware.camera2.CaptureRequest
 import android.hardware.camera2.CaptureResult
 import android.hardware.camera2.TotalCaptureResult
+import android.hardware.camera2.params.MeteringRectangle
 import android.media.Image
 import android.os.Build
 import android.util.Log
 import android.util.Range
+import android.util.Size
 import com.mrousavy.camera.extensions.SessionType
 import com.mrousavy.camera.extensions.capture
 import com.mrousavy.camera.extensions.createCaptureSession
@@ -44,6 +48,9 @@ class CameraSession(private val context: Context,
                     private val onError: (e: Throwable) -> Unit): CoroutineScope, Closeable, CameraOutputs.Callback, CameraManager.AvailabilityCallback() {
   companion object {
     private const val TAG = "CameraSession"
+
+    // TODO: Samsung advertises 60 FPS but only allows 30 FPS for some reason.
+    private val CAN_SET_FPS = Build.MANUFACTURER != "samsung"
   }
 
   data class CapturedPhoto(val image: Image,
@@ -76,6 +83,7 @@ class CameraSession(private val context: Context,
 
   private var captureSession: CameraCaptureSession? = null
   private var cameraDevice: CameraDevice? = null
+  private var previewRequest: CaptureRequest.Builder? = null
   private val photoOutputSynchronizer = PhotoOutputSynchronizer()
   private val mutex = Mutex()
   private var isRunning = false
@@ -290,6 +298,20 @@ class CameraSession(private val context: Context,
     }
   }
 
+  suspend fun focus(x: Int, y: Int) {
+    val captureSession = captureSession ?: throw CameraNotReadyError()
+    val previewOutput = outputs?.previewOutput ?: throw CameraNotReadyError()
+    val characteristics = cameraManager.getCameraCharacteristics(captureSession.device.id)
+    val sensorSize = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE)!!
+    val previewSize = previewOutput.size
+    val pX = x.toDouble() / previewSize.width * sensorSize.height()
+    val pY = y.toDouble() / previewSize.height * sensorSize.width()
+    val point = Point(pX.toInt(), pY.toInt())
+
+    Log.i(TAG, "Focusing (${point.x}, ${point.y})...")
+    focus(point)
+  }
+
   override fun onCameraAvailable(cameraId: String) {
     super.onCameraAvailable(cameraId)
     Log.i(TAG, "Camera became available: $cameraId")
@@ -300,6 +322,39 @@ class CameraSession(private val context: Context,
     Log.i(TAG, "Camera became un-available: $cameraId")
   }
 
+  private suspend fun focus(point: Point) {
+    mutex.withLock {
+      val captureSession = captureSession ?: throw CameraNotReadyError()
+      val request = previewRequest ?: throw CameraNotReadyError()
+
+      val weight = MeteringRectangle.METERING_WEIGHT_MAX - 1
+      val focusAreaTouch = MeteringRectangle(point, Size(150, 150), weight)
+
+      // Quickly pause preview
+      captureSession.stopRepeating()
+
+      request.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_CANCEL)
+      request.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_OFF)
+      captureSession.capture(request.build(), null, null)
+
+      // Add AF trigger with focus region
+      val characteristics = cameraManager.getCameraCharacteristics(captureSession.device.id)
+      val maxSupportedFocusRegions = characteristics.get(CameraCharacteristics.CONTROL_MAX_REGIONS_AE) ?: 0
+      if (maxSupportedFocusRegions >= 1) {
+        request.set(CaptureRequest.CONTROL_AF_REGIONS, arrayOf(focusAreaTouch))
+      }
+      request.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO)
+      request.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_AUTO)
+      request.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_START)
+
+      captureSession.capture(request.build(), false)
+
+      // Resume preview
+      request.set(CaptureRequest.CONTROL_AF_TRIGGER, CaptureRequest.CONTROL_AF_TRIGGER_IDLE)
+      captureSession.setRepeatingRequest(request.build(), null, null)
+    }
+  }
+
   /**
    * Opens a [CameraDevice]. If there already is an open Camera for the given [cameraId], use that.
    */
@@ -362,43 +417,27 @@ class CameraSession(private val context: Context,
     return session
   }
 
-  private fun getPreviewCaptureRequest(captureSession: CameraCaptureSession,
+  private fun getPreviewCaptureRequest(fps: Int? = null,
-                                       outputs: CameraOutputs,
-                                       fps: Int? = null,
                                        videoStabilizationMode: VideoStabilizationMode? = null,
                                        lowLightBoost: Boolean? = null,
                                        hdr: Boolean? = null,
                                        torch: Boolean? = null): CaptureRequest {
-    val template = if (outputs.videoOutput != null) CameraDevice.TEMPLATE_RECORD else CameraDevice.TEMPLATE_PREVIEW
+    val captureRequest = previewRequest ?: throw CameraNotReadyError()
-    val captureRequest = captureSession.device.createCaptureRequest(template)
-    outputs.previewOutput?.let { output ->
-      Log.i(TAG, "Adding output surface ${output.outputType}..")
-      captureRequest.addTarget(output.surface)
-    }
-    outputs.videoOutput?.let { output ->
-      Log.i(TAG, "Adding output surface ${output.outputType}..")
-      captureRequest.addTarget(output.surface)
-    }
 
-    if (fps != null) {
+    // FPS
-      // TODO: Samsung advertises 60 FPS but only allows 30 FPS for some reason.
+    val fpsRange = if (fps != null && CAN_SET_FPS) Range(fps, fps) else Range(30, 30)
-      val isSamsung = Build.MANUFACTURER == "samsung"
+    captureRequest.set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, fpsRange)
-      val targetFps = if (isSamsung) 30 else fps
 
-      captureRequest.set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, Range(targetFps, targetFps))
+    // Video Stabilization
-    }
+    captureRequest.set(CaptureRequest.CONTROL_VIDEO_STABILIZATION_MODE, videoStabilizationMode?.toDigitalStabilizationMode())
-    if (videoStabilizationMode != null) {
+    captureRequest.set(CaptureRequest.LENS_OPTICAL_STABILIZATION_MODE, videoStabilizationMode?.toOpticalStabilizationMode())
-      captureRequest.set(CaptureRequest.CONTROL_VIDEO_STABILIZATION_MODE, videoStabilizationMode.toDigitalStabilizationMode())
+
-      captureRequest.set(CaptureRequest.LENS_OPTICAL_STABILIZATION_MODE, videoStabilizationMode.toOpticalStabilizationMode())
+    // Night/HDR Mode
-    }
+    val sceneMode = if (hdr == true) CaptureRequest.CONTROL_SCENE_MODE_HDR else if (lowLightBoost == true) CaptureRequest.CONTROL_SCENE_MODE_NIGHT else null
-    if (lowLightBoost == true) {
+    captureRequest.set(CaptureRequest.CONTROL_SCENE_MODE, sceneMode)
-      captureRequest.set(CaptureRequest.CONTROL_SCENE_MODE, CaptureRequest.CONTROL_SCENE_MODE_NIGHT)
+    captureRequest.set(CaptureRequest.CONTROL_MODE, if (sceneMode != null) CaptureRequest.CONTROL_MODE_USE_SCENE_MODE else null)
-    }
+
-    if (hdr == true) {
+    // Zoom
-      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1) {
-        captureRequest.set(CaptureRequest.CONTROL_SCENE_MODE, CaptureRequest.CONTROL_SCENE_MODE_HDR)
-      }
-    }
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
       captureRequest.set(CaptureRequest.CONTROL_ZOOM_RATIO, zoom)
     } else {
@@ -407,6 +446,7 @@ class CameraSession(private val context: Context,
       captureRequest.set(CaptureRequest.SCALER_CROP_REGION, size.zoomed(zoom))
     }
 
+    // Torch Mode
     val torchMode = if (torch == true) CaptureRequest.FLASH_MODE_TORCH else CaptureRequest.FLASH_MODE_OFF
     captureRequest.set(CaptureRequest.FLASH_MODE, torchMode)
 
@@ -441,19 +481,32 @@ class CameraSession(private val context: Context,
           return@withLock
         }
 
-        // 2. Open Camera Device
+        // 1. Open Camera Device
         val camera = getCameraDevice(cameraId) { reason ->
           isRunning = false
           onError(reason)
         }
 
-        // 3. Create capture session with outputs
+        // 2. Create capture session with outputs
         val session = getCaptureSession(camera, outputs) {
           isRunning = false
         }
 
+        // 3. Create request template
+        val template = if (outputs.videoOutput != null) CameraDevice.TEMPLATE_RECORD else CameraDevice.TEMPLATE_PREVIEW
+        val captureRequest = camera.createCaptureRequest(template)
+        outputs.previewOutput?.let { output ->
+          Log.i(TAG, "Adding output surface ${output.outputType}..")
+          captureRequest.addTarget(output.surface)
+        }
+        outputs.videoOutput?.let { output ->
+          Log.i(TAG, "Adding output surface ${output.outputType}..")
+          captureRequest.addTarget(output.surface)
+        }
+
         Log.i(TAG, "Camera Session initialized! Starting repeating request..")
         isRunning = true
+        this.previewRequest = captureRequest
         this.captureSession = session
         this.cameraDevice = camera
       }
@@ -477,13 +530,9 @@ class CameraSession(private val context: Context,
       val videoStabilizationMode = videoStabilizationMode
       val lowLightBoost = lowLightBoost
       val hdr = hdr
-      val outputs = outputs
-      if (outputs == null || outputs.size == 0) {
-        Log.i(TAG, "CameraSession doesn't have any Outputs, canceling..")
-        return
-      }
 
-      val repeatingRequest = getPreviewCaptureRequest(session, outputs, fps, videoStabilizationMode, lowLightBoost, hdr)
+      val repeatingRequest = getPreviewCaptureRequest(fps, videoStabilizationMode, lowLightBoost, hdr)
+      Log.d(TAG, "Setting Repeating Request..")
       session.setRepeatingRequest(repeatingRequest, null, null)
     }
   }

android/src/main/java/com/mrousavy/camera/CameraView+Focus.kt

@@ -3,5 +3,7 @@ package com.mrousavy.camera
 import com.facebook.react.bridge.ReadableMap
 
 suspend fun CameraView.focus(pointMap: ReadableMap) {
-  // TODO: CameraView.focus!!
+  val x = pointMap.getInt("x")
+  val y = pointMap.getInt("y")
+  cameraSession.focus(x, y)
 }

android/src/main/java/com/mrousavy/camera/frameprocessor/Frame.java

@@ -104,11 +104,11 @@ public class Frame {
                 int vSize = vBuffer.remaining();
                 int totalSize = ySize + uSize + vSize;
 
-                if (byteArrayCache == null) {
+                if (byteArrayCache != null) byteArrayCache.rewind();
+                if (byteArrayCache == null || byteArrayCache.remaining() != totalSize) {
                     byteArrayCache = ByteBuffer.allocateDirect(totalSize);
                 }
 
-                byteArrayCache.rewind();
                 byteArrayCache.put(yBuffer).put(uBuffer).put(vBuffer);
 
                 return byteArrayCache;