#755 – Implementing Rotational Inertia during Touch Manipulation

In the same way that you can support inertia as a result of touch manipulation during translation and expansion, you can also set up rotational inertia.  When the user rotates an element using touch, the element has some initial rotational velocity (in deg/ms) when they lift their fingers off the screen.  You can then specify a desired value for a rotational deceleration (deg/ms^2).

As with translation and expansion, you specify the desired rotational deceleration in a handler for the ManipulationInertiaStarting event.  In the example below, we display the initial rotational velocity to the console and then specify a deceleration of 100 degrees/sec^2.  (Reduce velocity by 100 deg/sec each second).

        private void Image_ManipulationInertiaStarting(object sender, ManipulationInertiaStartingEventArgs e)
        {
            // Rotational inertia - 100 deg/sec^2 deceleration
            Console.WriteLine(string.Format("Initial rotational velocity = {0} deg/sec",
                e.RotationBehavior.InitialVelocity * 1000.0));
            e.RotationBehavior.DesiredDeceleration = 100.0 / (1000.0 * 1000.0);
        }

755-001

About Sean
Software developer in the Twin Cities area, passionate about .NET technologies. Equally passionate about my own personal projects related to family history and preservation of family stories and photos.

One Response to #755 – Implementing Rotational Inertia during Touch Manipulation

  1. Pingback: Dew Drop – February 13, 2013 (#1,498) | Alvin Ashcraft's Morning Dew

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: