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How to increase refresh rate on mouseMoveEvent?

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  • Y Yippiyak

    @Violet-Giraffe Your's is slightly faster, and it may not be possible, but there is still some lag in what you wrote as well. I am looking for tracking that would have no lag, and essentially be on par with a modern shooter game crosshair.
    Edit: what is the significance of the override command?

    mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by mrjj
    #6

    @Yippiyak
    Hi
    Do you by any way store points/lines while drawing ?
    if yes Can you try the
    http://doc.qt.io/qt-5/qtwidgets-widgets-scribble-example.html
    which uses dirty rect for updating and see if that is faster?

    override just means, "tell me if i dont actually override the virtual function"
    so if u flag something for override and u have wrong signature, compiler will tell you.

    Anyway, if you testing with a usb mouse, it might also just be the actually polling from Os side.
    in win 7 days, i used
    http://www.softpedia.com/get/Tweak/System-Tweak/USB-Mouserate-switcher.shtml
    but i have not tried in window 8+ if it still have any effect.

    Y 1 Reply Last reply
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    • mrjjM mrjj

      @Yippiyak
      Hi
      Do you by any way store points/lines while drawing ?
      if yes Can you try the
      http://doc.qt.io/qt-5/qtwidgets-widgets-scribble-example.html
      which uses dirty rect for updating and see if that is faster?

      override just means, "tell me if i dont actually override the virtual function"
      so if u flag something for override and u have wrong signature, compiler will tell you.

      Anyway, if you testing with a usb mouse, it might also just be the actually polling from Os side.
      in win 7 days, i used
      http://www.softpedia.com/get/Tweak/System-Tweak/USB-Mouserate-switcher.shtml
      but i have not tried in window 8+ if it still have any effect.

      Y Offline
      Y Offline
      Yippiyak
      wrote on last edited by
      #7

      @mrjj It is not the USB, but I am running about 1.4 million data points in the background so the the project is slow as a whole haha. Im just trying to see if there is a way to reduce the time necessary to call and update mouseMoveEvent.

      mrjjM 1 Reply Last reply
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      • Y Yippiyak

        @mrjj It is not the USB, but I am running about 1.4 million data points in the background so the the project is slow as a whole haha. Im just trying to see if there is a way to reduce the time necessary to call and update mouseMoveEvent.

        mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by
        #8

        @Yippiyak
        ah, so the mouse drawing cross paint event is shared with
        painting of the the points?

        1 Reply Last reply
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        • Y Offline
          Y Offline
          Yippiyak
          wrote on last edited by Yippiyak
          #9

          @mrjj
          No, its threaded and theoretically happens independently. Its just not tracking fast enough.

          mrjjM 1 Reply Last reply
          1
          • Y Yippiyak

            @mrjj
            No, its threaded and theoretically happens independently. Its just not tracking fast enough.

            mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #10

            @Yippiyak
            Ok. Normally in games they use hardware cursors to avoid this kind of trailing.
            https://stackoverflow.com/questions/6957039/what-is-hardware-cursor-and-how-does-it-work

            Im not sure there is a way, to make it go faster. Unless its due to something lagging/stressing the event queue
            or anything like that.

            Y 1 Reply Last reply
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            • mrjjM mrjj

              @Yippiyak
              Ok. Normally in games they use hardware cursors to avoid this kind of trailing.
              https://stackoverflow.com/questions/6957039/what-is-hardware-cursor-and-how-does-it-work

              Im not sure there is a way, to make it go faster. Unless its due to something lagging/stressing the event queue
              or anything like that.

              Y Offline
              Y Offline
              Yippiyak
              wrote on last edited by
              #11

              @mrjj
              Thanks for the tip on the hardware cursor, that may be the approach I need to take anyway in order to boost my programs performance. I am rendering a spectrogram and it is too slow!

              mrjjM 1 Reply Last reply
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              • Y Yippiyak

                @mrjj
                Thanks for the tip on the hardware cursor, that may be the approach I need to take anyway in order to boost my programs performance. I am rendering a spectrogram and it is too slow!

                mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #12

                @Yippiyak
                Is the spectrogram using openGL or just QPainter?

                Y 1 Reply Last reply
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                • mrjjM mrjj

                  @Yippiyak
                  Is the spectrogram using openGL or just QPainter?

                  Y Offline
                  Y Offline
                  Yippiyak
                  wrote on last edited by
                  #13

                  @mrjj
                  Just qpainter and qcharts atm, which I suspect is my issue, but I also have no real clue how to even begin with OpenGL. Also would you mind upvoting my reputation? I can only post once every 10 min and its getting annoying haha.

                  mrjjM 1 Reply Last reply
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                  • Y Yippiyak

                    @mrjj
                    Just qpainter and qcharts atm, which I suspect is my issue, but I also have no real clue how to even begin with OpenGL. Also would you mind upvoting my reputation? I can only post once every 10 min and its getting annoying haha.

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #14

                    @Yippiyak said in How to increase refresh rate on mouseMoveEvent?:

                    qcharts

                    well for QLineSeries and QScatterSeries, it seems easy
                    https://doc.qt.io/Qt-5/qtcharts-openglseries-example.html
                    for other im not sure.

                    Y 1 Reply Last reply
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                    • mrjjM mrjj

                      @Yippiyak said in How to increase refresh rate on mouseMoveEvent?:

                      qcharts

                      well for QLineSeries and QScatterSeries, it seems easy
                      https://doc.qt.io/Qt-5/qtcharts-openglseries-example.html
                      for other im not sure.

                      Y Offline
                      Y Offline
                      Yippiyak
                      wrote on last edited by
                      #15

                      @mrjj
                      Yeah im running the acceleration but its still not fast enough. Dumb part is the code works flawlessly in my c# implementation but C++ is brutalizing it. Should be the other way around.

                      mrjjM 1 Reply Last reply
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                      • Y Yippiyak

                        @mrjj
                        Yeah im running the acceleration but its still not fast enough. Dumb part is the code works flawlessly in my c# implementation but C++ is brutalizing it. Should be the other way around.

                        mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #16

                        @Yippiyak
                        Thats odd. what graph did you use with c# ?

                        Y 1 Reply Last reply
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                        • mrjjM mrjj

                          @Yippiyak
                          Thats odd. what graph did you use with c# ?

                          Y Offline
                          Y Offline
                          Yippiyak
                          wrote on last edited by
                          #17

                          @mrjj
                          A pretty basic line plot using direct3d hardware acceleration and like 60 other files lol

                          mrjjM 1 Reply Last reply
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                          • Y Yippiyak

                            @mrjj
                            A pretty basic line plot using direct3d hardware acceleration and like 60 other files lol

                            mrjjM Offline
                            mrjjM Offline
                            mrjj
                            Lifetime Qt Champion
                            wrote on last edited by mrjj
                            #18

                            @Yippiyak
                            Ok so most likely your plotter is just more specialized than QtChart and hence the speed difference.
                            You could try some test with direct openGL to see if it is faster

                            Y 1 Reply Last reply
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                            • mrjjM mrjj

                              @Yippiyak
                              Ok so most likely your plotter is just more specialized than QtChart and hence the speed difference.
                              You could try some test with direct openGL to see if it is faster

                              Y Offline
                              Y Offline
                              Yippiyak
                              wrote on last edited by
                              #19

                              @mrjj
                              Yeah, I think that is the issue, but I am not entirely sure how to get started with converting what I have to OpenGL and what not.

                              mrjjM 1 Reply Last reply
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                              • Y Yippiyak

                                @mrjj
                                Yeah, I think that is the issue, but I am not entirely sure how to get started with converting what I have to OpenGL and what not.

                                mrjjM Offline
                                mrjjM Offline
                                mrjj
                                Lifetime Qt Champion
                                wrote on last edited by
                                #20

                                @Yippiyak
                                well it really depends on how your layered your plotter
                                most of the work would to replace the Direct3D calls.
                                this is a very basic get started example
                                http://doc.qt.io/qt-5/qtgui-openglwindow-example.html

                                1 Reply Last reply
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                                • 6 Offline
                                  6 Offline
                                  6ziv
                                  wrote on last edited by
                                  #21

                                  Well in my opinion maybe you can try not refreshing immediately. Just record the position in a fifo and return. You can get yourself another thread which looks through the fifo and draws, so the handler may return faster, and missing fewer. Well...in fact I am not very sure of this....

                                  1 Reply Last reply
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