BaconographyWP8.View.ScalingGifView.myGridGestureListener_DoubleTap C# (CSharp) Method

        private void myGridGestureListener_DoubleTap(object sender, Microsoft.Phone.Controls.GestureEventArgs e)
        {
            var point = e.GetPosition(image);
            _relativeMidpoint = new Point(point.X / image.ActualWidth, point.Y / image.ActualHeight);

            var xform = image.TransformToVisual(viewport);
            _screenMidpoint = xform.Transform(point);

            if (_coercedScale >= (_minScale * 2.5) || _coercedScale < 0)
                _coercedScale = _minScale;
            else
                _coercedScale *= 1.75;

            ResizeImage(false);
        }