helix-toolkit/helix-toolkit — pull request #84 by johnsonlu (2014-11-18 07:43:29+00:00)
Title: Do not raise ModelsSelectionByRectangleEventArgs when the size of rectangle is zero

Do not raise ModelsSelectionByRectangleEventArgs if the rectangle size is zero. Except no models are hit, we raise the event args to clear the existing selection.