[camera] Allow logical cameras to use all physical cameras via zoom on android 11+

packages/camera/camera_android/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.10.0+1
+
+* Fixes zoom computation for virtual cameras hiding physical cameras in Android 11+.
+* Removes the unused CameraZoom class from the codebase. 
+
 ## 0.10.0
 
 * **Breaking Change** Updates Android camera access permission error codes to be consistent with other platforms. If your app still handles the legacy `cameraPermission` exception, please update it to handle the new permission exception codes that are noted in the README.

packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/CameraProperties.java

@@ -150,10 +150,32 @@ public interface CameraProperties {
    * android.hardware.camera2.CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM key.
    *
    * @return Float Maximum ratio between both active area width and crop region width, and active
-   *     area height and crop region height
+   *     area height and crop region height.
    */
   Float getScalerAvailableMaxDigitalZoom();
 
+  /**
+   * Returns the minimum ratio between the default camera zoom setting and all of the available zoom
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_ZOOM_RATIO_RANGE key's lower value.
+   *
+   * @return Float Minimum ratio between the default zoom ratio and the maximum possible zoom
+   */
+  @RequiresApi(api = VERSION_CODES.R)
+  Float getScalerMinZoomRatio();
+
+  /**
+   * Returns the maximum ratio between the default camera zoom setting and all of the available zoom
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_ZOOM_RATIO_RANGE key's upper value.
+   *
+   * @return Float Maximum ratio between the default zoom ratio and the maximum possible zoom
+   */
+  @RequiresApi(api = VERSION_CODES.R)
+  Float getScalerMaxZoomRatio();
+
   /**
    * Returns the area of the image sensor which corresponds to active pixels after any geometric
    * distortion correction has been applied.
@@ -315,6 +337,18 @@ public Float getScalerAvailableMaxDigitalZoom() {
     return cameraCharacteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
   }
 
+  @RequiresApi(api = VERSION_CODES.R)
+  @Override
+  public Float getScalerMaxZoomRatio() {
+    return cameraCharacteristics.get(CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE).getUpper();
+  }
+
+  @RequiresApi(api = VERSION_CODES.R)
+  @Override
+  public Float getScalerMinZoomRatio() {
+    return cameraCharacteristics.get(CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE).getLower();
+  }
+
   @Override
   public Rect getSensorInfoActiveArraySize() {
     return cameraCharacteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);

packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/zoomlevel/ZoomLevelFeature.java

@@ -6,16 +6,18 @@
 
 import android.graphics.Rect;
 import android.hardware.camera2.CaptureRequest;
+import android.os.Build;
 import io.flutter.plugins.camera.CameraProperties;
 import io.flutter.plugins.camera.features.CameraFeature;
 
 /** Controls the zoom configuration on the {@link android.hardware.camera2} API. */
 public class ZoomLevelFeature extends CameraFeature<Float> {
-  private static final float MINIMUM_ZOOM_LEVEL = 1.0f;
+  private static final Float defaultZoomLevel = 1.0f;
   private final boolean hasSupport;
   private final Rect sensorArraySize;
-  private Float currentSetting = MINIMUM_ZOOM_LEVEL;
-  private Float maximumZoomLevel = MINIMUM_ZOOM_LEVEL;
+  private Float currentSetting = defaultZoomLevel;
+  private Float minimumZoomLevel = currentSetting;
+  private Float maximumZoomLevel;
 
   /**
    * Creates a new instance of the {@link ZoomLevelFeature}.
@@ -28,18 +30,24 @@ public ZoomLevelFeature(CameraProperties cameraProperties) {
     sensorArraySize = cameraProperties.getSensorInfoActiveArraySize();
 
     if (sensorArraySize == null) {
-      maximumZoomLevel = MINIMUM_ZOOM_LEVEL;
+      maximumZoomLevel = minimumZoomLevel;
       hasSupport = false;
       return;
     }
+    // On Android 11+ CONTROL_ZOOM_RATIO_RANGE should be use to get the zoom ratio directly as minimum zoom does not have to be 1.0f
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+      minimumZoomLevel = cameraProperties.getScalerMinZoomRatio();
+      maximumZoomLevel = cameraProperties.getScalerMaxZoomRatio();
+    } else {
+      minimumZoomLevel = defaultZoomLevel;
+      Float maxDigitalZoom = cameraProperties.getScalerAvailableMaxDigitalZoom();
+      maximumZoomLevel =
+          ((maxDigitalZoom == null) || (maxDigitalZoom < minimumZoomLevel))
+              ? minimumZoomLevel
+              : maxDigitalZoom;
+    }
 
-    Float maxDigitalZoom = cameraProperties.getScalerAvailableMaxDigitalZoom();
-    maximumZoomLevel =
-        ((maxDigitalZoom == null) || (maxDigitalZoom < MINIMUM_ZOOM_LEVEL))
-            ? MINIMUM_ZOOM_LEVEL
-            : maxDigitalZoom;
-
-    hasSupport = (Float.compare(maximumZoomLevel, MINIMUM_ZOOM_LEVEL) > 0);
+    hasSupport = (Float.compare(maximumZoomLevel, minimumZoomLevel) > 0);
   }
 
   @Override
@@ -67,11 +75,19 @@ public void updateBuilder(CaptureRequest.Builder requestBuilder) {
     if (!checkIsSupported()) {
       return;
     }
-
-    final Rect computedZoom =
-        ZoomUtils.computeZoom(
-            currentSetting, sensorArraySize, MINIMUM_ZOOM_LEVEL, maximumZoomLevel);
-    requestBuilder.set(CaptureRequest.SCALER_CROP_REGION, computedZoom);
+    // On Android 11+ CONTROL_ZOOM_RATIO can be set to a zoom ratio and the camera feed will compute
+    // how to zoom on its own accounting for multiple logical cameras.
+    // Prior the image cropping window must be calculated and set manually.
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+      requestBuilder.set(
+          CaptureRequest.CONTROL_ZOOM_RATIO,
+          ZoomUtils.computeZoomRatio(currentSetting, minimumZoomLevel, maximumZoomLevel));
+    } else {
+      final Rect computedZoom =
+          ZoomUtils.computeZoomRect(
+              currentSetting, sensorArraySize, minimumZoomLevel, maximumZoomLevel);
+      requestBuilder.set(CaptureRequest.SCALER_CROP_REGION, computedZoom);
+    }
   }
 
   /**
@@ -80,7 +96,7 @@ public void updateBuilder(CaptureRequest.Builder requestBuilder) {
    * @return The minimum zoom level.
    */
   public float getMinimumZoomLevel() {
-    return MINIMUM_ZOOM_LEVEL;
+    return minimumZoomLevel;
   }
 
   /**

packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/zoomlevel/ZoomUtils.java

@@ -18,17 +18,18 @@ final class ZoomUtils {
    * Computes an image sensor area based on the supplied zoom settings.
    *
    * <p>The returned image sensor area can be applied to the {@link android.hardware.camera2} API in
-   * order to control zoom levels.
+   * order to control zoom levels. This method of zoom should only be used for Android versions
+   * <= 11 as past that, the newer {@link #computeZoomRatio()} functional can be used.
    *
    * @param zoom The desired zoom level.
    * @param sensorArraySize The current area of the image sensor.
    * @param minimumZoomLevel The minimum supported zoom level.
    * @param maximumZoomLevel The maximim supported zoom level.
    * @return An image sensor area based on the supplied zoom settings
    */
-  static Rect computeZoom(
+  static Rect computeZoomRect(
       float zoom, @NonNull Rect sensorArraySize, float minimumZoomLevel, float maximumZoomLevel) {
-    final float newZoom = MathUtils.clamp(zoom, minimumZoomLevel, maximumZoomLevel);
+    final float newZoom = computeZoomRatio(zoom, minimumZoomLevel, maximumZoomLevel);
 
     final int centerX = sensorArraySize.width() / 2;
     final int centerY = sensorArraySize.height() / 2;
@@ -37,4 +38,8 @@ static Rect computeZoom(
 
     return new Rect(centerX - deltaX, centerY - deltaY, centerX + deltaX, centerY + deltaY);
   }
+
+  static Float computeZoomRatio(float zoom, float minimumZoomLevel, float maximumZoomLevel) {
+    return MathUtils.clamp(zoom, minimumZoomLevel, maximumZoomLevel);
+  }
 }

packages/camera/camera_android/android/src/test/java/io/flutter/plugins/camera/CameraPropertiesImplTest.java

@@ -201,6 +201,30 @@ public void getScalerAvailableMaxDigitalZoomTest() {
     assertEquals(actualDigitalZoom, expectedDigitalZoom);
   }
 
+  @Test
+  public void getScalerGetScalerMinZoomRatioTest() {
+    Range zoomRange = mock(Range.class);
+    when(mockCharacteristics.get(CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE))
+        .thenReturn(zoomRange);
+
+    Float minZoom = cameraProperties.getScalerMinZoomRatio();
+
+    verify(mockCharacteristics, times(1)).get(CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE);
+    assertEquals(zoomRange.getLower(), minZoom);
+  }
+
+  @Test
+  public void getScalerGetScalerMaxZoomRatioTest() {
+    Range zoomRange = mock(Range.class);
+    when(mockCharacteristics.get(CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE))
+        .thenReturn(zoomRange);
+
+    Float maxZoom = cameraProperties.getScalerMaxZoomRatio();
+
+    verify(mockCharacteristics, times(1)).get(CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE);
+    assertEquals(zoomRange.getUpper(), maxZoom);
+  }
+
   @Test
   public void getSensorInfoActiveArraySizeTest() {
     Rect expectedArraySize = mock(Rect.class);