Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. QTouchEvents capturing very slow.
Qt 6.11 is out! See what's new in the release blog

QTouchEvents capturing very slow.

Scheduled Pinned Locked Moved General and Desktop
3 Posts 2 Posters 1.1k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • musimbateM Offline
    musimbateM Offline
    musimbate
    wrote on last edited by
    #1

    Hi ,
    I am trying to implement multitouch in my application and catching events combining the techniques used n the fingerpaint and pinchzoom examples.
    Events are being captured and I am drawing in the scene but the points are being very scattered as you move the mouse fast. The effect I am getting can be seen "here":http://www.blikoon.com/?attachment_id=1655

    Is there anyting more I need to do to get the points drawn as they would in a normal mousemove event?Or am I just going a wrong way about this?

    Any help would be appreciated.

    Why join the navy if you can be a pirate?-Steve Jobs

    1 Reply Last reply
    0
    • J Offline
      J Offline
      john_larring
      wrote on last edited by
      #2

      Hi,
      What you see is the effect of the sampling rate of the multitouch hardware. In some hardware drivers (e.g. PQ Labs and NextWindow), you can adjust the sampling rate. But even with a 120Hz sampling rate the scattering won't be eliminated for very fast movements. To hide the scattering effect you could always draw line segments between points instead of just drawing points.

      Kind regards,
      John

      1 Reply Last reply
      0
      • musimbateM Offline
        musimbateM Offline
        musimbate
        wrote on last edited by
        #3

        Thanks john_larring ,
        It seems that this is the only way around this.I try it and see the effect.

        Why join the navy if you can be a pirate?-Steve Jobs

        1 Reply Last reply
        0

        • Login

        • Login or register to search.
        • First post
          Last post
        0
        • Categories
        • Recent
        • Tags
        • Popular
        • Users
        • Groups
        • Search
        • Get Qt Extensions
        • Unsolved