private void OnRegionResize(Resizer resizer, Region region)
 {
     UpdateDepthMaskTransform(region, m_dragDepthMasks[0]);
 }
 private void OnRegionEndResize(Resizer resizer, Region region)
 {
     m_dragDepthMasks = null;
 }
 private void OnRegionBeginResize(Resizer resizer, Region region)
 {
     m_dragDepthMasks = new[] { m_regionToDepthMask[region] };
 }