Combining transforms into TransformGroup

Hi all,

I want to apply a series of transforms to a canvas. The transforms consist of scales, rotates and translates. They will to have be applied dynamically and in a random order. For instance: a canvas is translated but next it will have to be rotated around a certain center, scaled around a center, rotated again, translated again, ... I used a transformgroup and because I know that the order of transforms is important, I added them to the transformgroup in a way the first in the group are all the scales, next the rotates and finally the translates. This works well for a while but after a certain time a get performance problems when there are too many transforms in the group. Is there a way to overcome this?

Thx al lot,

Maarten

Hello Maarten,
The performance issue could have to do with several things.
First: Do you use Canvas.Rendertransform or Canvas.LayoutTransform? Layouttransform causes the Application the call an entire Layoutprocess, which takes much more time than Rendertransform.

But I think your problem is, that you may call all the functions in the loop. This is critical, since the transformation has not been finished, before a other transformation is called. I would reccomand to use the class DispatcherTimer from System.Windows.Threading:

  DispatcherTimer dispatcherTimer = new DispatcherTimer();
            //give Ticker values
            dispatcherTimer.Tick += new EventHandler(NextAnimation);
            
            // do Transformation every 10 milisecond
            dispatcherTimer.Interval = new TimeSpan(0, 0,0,0, 100);

The Dispatcherclass has a eventhandler Toick, which throws an event every Interval. In this event Handler, you can call your animation. I have created a small example Application for you: http://www.pklitzke.com/Schooldata/MyTransform.zip