title: How to solve touch input lag for Windows 8 game?
body: <p>I am currently developing a game for Windows 8 using C++ with pure XAML (no DirectX.) At some point, I start noticing a lag when touch inputs occur (e.g. Tap.) Mouse click (or other mouse events) doesn't cause the same lag issue. I also notice the more touch fingers, the more lag happens.</p>
  
  <p>This issue seems to be specific to XAML apps only, either C++ or C#. I tried with sample Direct3D project and all seems fine.</p>
  
  <p>I created a clean slate C++ XAML app with almost nothing except 1 Ellipse control that has a Storyboard to animate it around the page, then tried disabling all inputs on root control by setting IsRightTapEnabled/IsHoldingEnabled/IsDoubleTapEnabled/ManipulationMode/IsTapEnabled/IsHitTestVisible to False. But the lag still happens when triggering touch inputs.</p>
  
  <p>So from this, I'm sure there has to be something wrong at the fundamental level. The app almost does nothing and the lag still occurs.</p>
  
  <p>There are games like Hydro Thunder and Jetpack Joyride on Windows 8 that also have a touch input lag issue (see <a href="http://wrtapps.com/2012/12/windows-rt-games-suffering-from-touch-screen-input-lag/" rel="nofollow">http://wrtapps.com/2012/12/windows-rt-games-suffering-from-touch-screen-input-lag/</a>). Somehow they managed to fix it already.</p>
  
  <p>I believe there must be a way to fix this (as somehow guys from Halfbrick already did so.) It's almost like touch on Windows 8 is eating more CPU than usual. But I couldn't figure out how to prevent that. I couldn't find any other articles blogging about this issue also. Now I run out of clue :(</p>
  
  <p>Any suggestions to this issue would be very much appreciated!</p>