question: private static MeteringRectangle [ ] regionsForNormalizedCoord ( float nx , float ny , float fraction , final Rect cropRegion , int sensorOrientation ) { int minCropEdge = Math . min ( cropRegion . width ( ) , cropRegion . height ( ) ) ; int halfSideLength = ( int ) ( 0.5f * fraction * minCropEdge ) ; PointF nsc = CameraUtil . normalizedSensorCoordsForNormalizedDisplayCoords ( nx , ny , sensorOrientation ) ; int xCenterSensor = ( int ) ( cropRegion . left + nsc . x * cropRegion . width ( ) ) ; int yCenterSensor = ( int ) ( cropRegion . top + nsc . y * cropRegion . height ( ) ) ; Rect meteringRegion = new Rect ( xCenterSensor - halfSideLength , yCenterSensor - halfSideLength , xCenterSensor + halfSideLength , yCenterSensor + halfSideLength ) ; meteringRegion . left = CameraUtil . clamp ( meteringRegion . left , cropRegion . left , cropRegion . right ) ; meteringRegion . top = CameraUtil . clamp ( meteringRegion . top , cropRegion . top , cropRegion . bottom ) ; meteringRegion . right = CameraUtil . clamp ( meteringRegion . right , cropRegion . left , cropRegion . right ) ; meteringRegion . bottom = CameraUtil . clamp ( meteringRegion . bottom , cropRegion . top , cropRegion . bottom ) ; return new MeteringRectangle [ ] { new MeteringRectangle ( meteringRegion , CAMERA2_REGION_WEIGHT ) } ; }
target:  Compute 3A regions for a sensor-referenced touch coordinate. Returns a MeteringRectangle[] with length 1.