In hidpi mode effects applying to coordinates that two times smaller then they should be. I can't reproduce it in standalone sample. But it appears in tests. See attached screenshots. Here shadow offset is two times smaller(CanvasEffects2Test-InnerShadowoffset__10__20_hidpi.png) then should be(CanvasEffects2Test-InnerShadowoffset__10__20.png) for both axes.