Scale image animation - performance issue

qtd1d1

Hi,

after reading this forum post: "performance images":http://developer.qt.nokia.com/wiki/Performance_tip_Images
I wondered how is it possible to get a smooth and velvet scaling animation?

Is there probably a possibility to improve the performance of my scaling animation?
That's how I implemented it right now:

That's the image
@
Image {
id: item

            scale: 0.800
            clip: false

            anchors.left: tachoitem.left
            anchors.top: tachoitem.top
            anchors.leftMargin: 210
            anchors.topMargin: 30


            source: "images/item.png"
            sourceSize.width: 370
            sourceSize.height: 370
            smooth: true

        }@

That's the Animation
@ParallelAnimation {
id: scaleoutLeft
running: scaleout

            NumberAnimation { target: item; easing.type: Easing.InExpo;property: "x"; to: 100; duration: 1000 }
         
            NumberAnimation { target: item; property: "scale"; to: 1; duration: 1000 }
        }@

Thanks

diro

What is your type of viewport? QGLWidget?

qtd1d1

Yes i am using qglwidget.

mbrasser

Hi,

One of the tips on the wiki is:

bq. If you really need to enable Image.smooth, disable smooth filtering at the beginning of the animation and re-enable it at the end of the animation (scaling artifacts are only visible if the image is stationary on the screen)

That is what I would suggest in this case. In general this looks something like:

@
SequentialAnimation {
PropertyAction { target: item; property: "smooth"; value: false }
NumberAnimation { target: item; property: "scale"; to: 1; duration: 1000 }
PropertyAction { target: item; property: "smooth"; value: true }
}
@

Regards,
Michael

minimoog77

Scaling of images when done on OpenGL is 'free'.

But, notice that anchors/positions are reevaluated on every scale step, so I think performance issue when doing scaling are there (can somebody confirm?).

qtd1d1

Ok, I will try to turn off antialiasing during the animation and post the results later. Thank you

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Scale image animation - performance issue