double buffering and vsync?

Question

Do silverlight support double buffering and vsync?

 I am a beginner to silverlight, I tried to make a little ticker animation which translate textblock from left to right with silverlight. The performance is not very good at all. I think the problem is related to double buffering and vsync.

 

Thanks.
 

Answer 1

Yes, we do double buffer.  Whether you get vtrace tearing depends on the OS you are running on.  

What browser and platform are you running on?  Something as simple as translating a textblock should run at very high framerates.

Some gotcha's to watch out for:

1. set windowless=false on the control (fastest mode and less tearing)
2. make sure the background is not transparent

- Ashraf Michail
 

Answer 2

 Even the control is set windowless: 'false', the textblock does not move smoothly. I wonder how can I create a smooth ticker

 

The textblock I have made is

<TextBlock x:Name="text" Canvas.Top="0" Canvas.Left="0" Width="450" Height="100" FontSize="72" Text="TextBlock" TextWrapping="Wrap">
        <TextBlock.RenderTransform>
            <TranslateTransform x:Name="AnimatedRotateTransform" X="0" Y="0"/>
        </TextBlock.RenderTransform>
       
        <TextBlock.Triggers>

        <!-- Animates the rectangle's opacity. -->
        <EventTrigger RoutedEvent="TextBlock.Loaded">
          <BeginStoryboard>
            <Storyboard>
              <DoubleAnimation
                Storyboard.TargetName="AnimatedRotateTransform"
                Storyboard.TargetProperty="X"
                From="1024" To="-450" Duration="0:0:5"
                AutoReverse="False" RepeatBehavior="Forever" />
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </TextBlock.Triggers>
    </TextBlock>

 Thanks

Answer 3

I take it you've already tried increasing the framerate?

Answer 4

I have tried 24 and even 36, the textblock still does not move smoothly

Answer 5

There's no reason I'm aware of that you can't go higher than that.  I tried it at 200 and it looked pretty nice.

Answer 6

 I have tried to enable frame rate counter and it shows that the demo is now running at around 100 fps. Tearing is still there.

Answer 7

Tearing will be present on XP but shouldn't be present on Vista or MacOS if you set windowless=false.

 

Answer 8

Is there any workaround in winXP?

If there is no, is there any plan that the feature will be supported in future release of silverlight?

 

 Thanks

Answer 9

This thread seems to have stalled with no resolution.

Vsync seems to be an ongoing issue for a number of people using Silverlight.  The issue is not limited to the poster above - Netflix for instance has page tearing issues now that it uses Silverlight.

 How can developers and users prevent page tearing?

 

Answer 10

Is there a flag somewhere that indicates when a refresh is in progress? I know that seems unlikely since the plugin doesn't have that much access to the GPU, but it might help us prevent shearing when implementing procedural animation.