[Interest] Performance tips for 'ticker' animation?

[Cornelius Hald]

I've now tried replacing the Text element with an Image element.
Performance is better but still not totally smooth. I'll guess I should
try different (more powerful) hardware now and hope for improvements in
future Qt versions.

Thanks for all the input!
Conny

On Wed, 2013-08-07 at 16:58 +0200, Cornelius Hald wrote:
> That sounds like an option and I'll give it a try using a manually
> created bitmap. If this works I'll consider creating this pixmap
> dynamically during runtime.
> 
> In the mean time I've tried optimizing the animation by putting the text
> on a rectangle with solid background and animating that rectangle
> instead of the text element. Also tried setting "layer.enabled: true" on
> that rectangle, but it didn't help anything.
> 
> If anyone has other ideas, please let me know.
> 
> Thanks,
> Conny
> 
> 
> On Wed, 2013-08-07 at 14:23 +0000, bill.king at here.com wrote:
> > I'm shooting in the dark here, but possibly the issue could be continued re-rendering of the text. I found this way of animating a ticker to be high in cost of cpu cycles. If you can render to a pixmap, then scroll/blit the pixmap through a view area, this ends up being a very low cost way of achieving animation (and for me, also resulted in much better fluidity)
> > 
> > --
> > 
> > Bill King
> > Senior QA Engineer
> > TRG Group
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> > 
> > > -----Original Message-----
> > > From: interest-bounces+bill.king=nokia.com at qt-project.org
> > > [mailto:interest-bounces+bill.king=nokia.com at qt-project.org] On Behalf Of
> > > ext Cornelius Hald
> > > Sent: Monday, 5 August 2013 11:49 AM
> > > To: Interest at qt-project.org
> > > Subject: [Interest] Performance tips for 'ticker' animation?
> > > 
> > > Hi guys,
> > > 
> > > I'm having a kiosk application displaying video and web content in FullHD
> > > using QtQuick 2.1 on Linux Qt 5.1.
> > > 
> > > Now I've added a text ticker that sits at the bottom of the screen and scrolls
> > > text from right to left.
> > > 
> > > If I only display the ticker, the animation is smooth. But as soon as I play a
> > > video or display (static) web content in the background, the ticker animation
> > > starts to stutter quite badly. Still the CPU load is only around 30%.
> > > 
> > > Does anyone have some tips on how to improve the visual smoothness of
> > > the ticker animation?
> > > 
> > > Below is the code I'm currently using to animate the ticker.
> > > 
> > > Thanks,
> > > Conny
> > > 
> > > 
> > > import QtQuick 2.1
> > > Rectangle {
> > >   id: root
> > >   property alias text: text.text
> > >   height: 100
> > >   color: "red"
> > > 
> > >   Text {
> > >     id: text
> > >     text: "This is some ticker text that gets displayed whenever you're seeing
> > > this ticker here, bla bla bla..."
> > >     color: "white"
> > >     font.pixelSize: 80
> > >     anchors.verticalCenter: parent.verticalCenter
> > > 
> > >     NumberAnimation on x {
> > >       from: root.width
> > >       to: -text.width
> > >       duration: text.width * 10
> > >       loops: Animation.Infinite
> > >       onFromChanged: restart()
> > >     }
> > >   }
> > > }
> > > 
> > > 
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> 
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