Monday, May 18, 2009

Wolfram Alpha Computational Knowledge Engine

Wolfram Alpha Answer Engine gets us to what people thought computers would be able to do 50 years ago: quickly find answers to all the factual questions!

Stephen Wolfram, the British physicist behind this recently launched project clarifies that Wolfram Alpha is a website with one simple input field that gives access to a huge system, with trillions of pieces of curated data and millions of lines of algorithms.


It is not a search engine that lists out numerous links to information that exist on the web. Instead, it actually computes the answer using the available data and displays it in a easily readable format.


Thursday, May 14, 2009

Microsoft Surface Applications - Deployment and Object Routing

Continued from: Microsoft Surface Tagged Objects and Tag Visualizations

When users interact with a Microsoft Surface unit, they launch the applications from Launcher.  Launcher is the menu that displays the applications that are available to users in a horizontal interactive strip.

 As part of deploying the Surface application, we must register it with Surface so that it is available in the Launcher. This is done by copying the application’s xml file to the Surface’s program data folder (%PROGRAMDATA%\Microsoft\Surface\Programs).

This application xml file is created by default when the Visual Studio project template is used. Otherwise, we can create a normal xml file with the file name equivalent as the project (executable) name and with the following tags.
<?xml version="1.0" encoding="utf-8" ?>
    <Title>My Surface App</Title>
    <Description>This is a sample Surface application.</Description>
      <ByteTag Value="C0">
          <Launch />
The <Application> tag specifies that this is a normal Surface application. Other options are <AttractApplication> for attract mode (similar to screen saver) applications and <ServiceApplication> for apps that run in the background and does not have a UI.

The <Title> is displayed on the Launcher all the time, and <Description> is displayed when the application is selected from the Launcher. <ExecutableFile> specifies the path to the actual application exe. If the application is accepting any command line arguments it can be supplied through <Arguments> tag. <IconImageFile> specifies the png image to be displayed in the Launcher as application icon and <Preview> specifies the image to be displayed when the application is selected in the Launcher. This can be a bigger static image(<PreviewImageFile>) or a slideshow of images(<SlideshowImageFile>) or a movie (<MovieFile>).

The <Tags> specify the tags used by the application and <Launch> is used to specify that the particular tag value is used for object routing (which is discussed later).

To summarize the deployment steps again:
  • Build your Surface application in Release mode.
  • Copy all the files from the build folder to any location in the Surface computer (typically %ProgramFiles%\CompanyName\ApplicationName\).
  • Make sure that this path is specified in the Application’s xml file.
  • Copy the Application’s xml file to (%PROGRAMDATA%\Microsoft\Surface\Programs folder.
That’s all to it and the application will now be available in the Launcher for the user to see and launch.

Tagged Object Routing
On 2009-May-10, Microsoft released its first Service Pack (SP1) to Surface 1.0 with lots of new features and improvements. Read about them at official Surface blog.

Object Routing is one of the new SP1 features that enable the developer to configure tagged objects which can open applications without using Launcher. The tagged object can be placed anywhere on the Surface interface (attract applications, other non-registered applications or the Launcher) to bring up the list of applications that are registered with that tag. The applications will appear as tiny bubbly icons that smoothly pops up from the object and can be launched by touching them.

To enable the object routing for an applications:
  • Specify the required type of tag (Byte/Identity) within the <Tags> section of the application’s xml file and specify its value and have the <Actions> as <Launch>.
<ByteTag Value="C0">
    <Launch />

<IdentityTag Series="4245A8E4901C2C0B">
    <Launch /> 

I have used an example value of C0 for Byte tag and 4245A8E4901C2C0B for Identity tag.
  • Create a new registry key using this tag value under TagInfo section as below:

  • Add the following String Value items on this key
    • Text : ‘object routing card title’.
    • BoundingBoxWidth : ‘3.25’.
    • BoundingBoxHeight : ‘2.125’.
    • PhysicalCenterOffsetFromTagX : ‘0’.
    • PhysicalCenterOffsetFromTagY : ‘0’.
    • OrientationOffsetFromTag : ‘0’.
This specifies the size of tagged object (business card size is 3.25 x 2.125 inches) and the location of the tag within this object (Zero means there is no offset from the center of the object; the tag is exactly on the center of this business card sized object)

Note that the other registry settings (enabled by default) to enable Object Routing (HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Surface\v1.0\Shell\EnableObjectRouting ) must be set as well.

That’s all the settings we need to do to get object routing work. Now if you place a tag with the specified value, all the applications that have this tag value in their xml file registered will popup from this object.

If you have done everything right, and still its not working as expected, refer the event log (run the command eventvwr) and navigate to Applications and Services Logs/Microsoft/Surface/Shell/Operational for any possible warnings or errors. Chances are that there is some error in the application's xml file or the registry settings. A sample warning (when the required registry entry is not present) looks like below:
The application info file C:\ProgramData\Microsoft\Surface\Programs\Macroni.xml refers to tag 29EB049F73061803, however, some configuration information for 29EB049F73061803 is missing from the registry. The default value '2.125' will be used for the missing setting.
Path to the tag's missing configuration setting in the registry:
Happy coding!

Monday, May 11, 2009

Microsoft Surface Tagged Objects and Tag Visualizations

Continued from Developing Microsoft Surface Applications

Microsoft Surface applications can recognize special tags besides fingers and  objects. These tags are similar to bar codes in concept and can store a particular value which can be retrieved by Surface’s vision system.

Tags are a pattern of white dots (infrared reflective) in black background (infrared absorbing) and are normally printed on a card or are printed and stuck to the plain surface of an object. Such objects with a tag are called as Tagged Objects.

Microsoft Surface supports two types of tags:

Byte Tags
  • Stores 8 bits of data (1 byte).
  • 256 possible unique values.
  • Smaller size (3/4 x 3/4 inches).
  • Reliable tracking even for faster moving tags.
  • Represented in code by ByteTag structure.
  • ByteTag.Value property represents the tag value.
Identity Tags
  • Stores 128 bits of data (two 64 bit values).
  • Larger range of possible unique values (i.e. 340,282,366,920,938,000,000,000,000,000,000,000,000).
  • Larger size (1 x 1 inches).
  • Functions better when tags are stationary or nearly stationary.
  • Represented in code by IdentityTag structure.
  • IdentityTag.Series and IdentityTag.Value together represents the tag value.
These tags are usually pre-printed and available from Microsoft or are printed using special tools that come with the Surface SDK.

Now let us build a sample application that deals with tagged objects. Create a new Surface project and add three Tag Visualization items (Add > New Item > Visual C# > Surface > v1.0 > Tag Visualization (WPF)). These items defines the UI that appears when a tagged object is placed on Surface. For now, let us just specify a height and width for it and then have a blank grid with a background color.
<s:TagVisualization x:Class="TagSample.BlueTags"
    Loaded="BlueTags_Loaded" Height="50" Width="50">
    <Grid Background="Blue">

Now add the following XAML code in the SurfaceWindow1.xaml

<Grid Background="{StaticResource WindowBackground}" >
  <s:TagVisualizer VisualizationAdded="OnVisualizationAdded" >
      <!-- ByteTag: 10 = A -->
      <s:ByteTagVisualizationDefinition Value="10"
      <!-- ByteTag: 250 = FA -->
      <s:ByteTagVisualizationDefinition Value="250"

      <!-- IdentityTag: 500 = 1F4, 1000 = 3E8 -->
      <s:IdentityTagVisualizationDefinition Series="500" Value="1000"
    <DockPanel LastChildFill="False">
      <TextBlock x:Name="uxDisplay"
                 Text="Watch here"/>

TagVisualizer is a content control that automatically displays visualization objects when a tag is placed on the control.  We keep this as the root containing control within Grid. Then we define three tags using TagVisualizationDefinition. Each definition specifies what kind of tag (Byte or Identity) we are using, its value, and the source file for TagVisualization. Finally we have a TextBlock to display the values.

Also note that we have defined VisualizationAdded event on the TagVisualizer. This gets fired whenever a tag is placed. Add the following code to handle this event.

void OnVisualizationAdded(object sender, TagVisualizerEventArgs e)
    String type = "";
    String value = "";

    if (e.TagVisualization.VisualizedTag.Type == TagType.Byte)
        type = "Byte Tag";
        value = e.TagVisualization.VisualizedTag.Byte.Value.ToString();
    else if (e.TagVisualization.VisualizedTag.Type == TagType.Identity)
        type = "Identity Tag";
        value = e.TagVisualization.VisualizedTag.Identity.Series.ToString() + " - " + e.TagVisualization.VisualizedTag.Identity.Value.ToString();

    uxDisplay.Text = type + ":" + value;

In this code, we are retrieving the tag information from the event arguments and then display it in a text box.


Run the application and try placing different tags. Note that the integer values need to be converted to Hexadecimal format while using in the simulator (I use Windows Calculator, change its View to Scientific, use ‘Dec’ option for decimal, type in a number and then choose ‘Hex’ option to convert it to Hexadecimal value) (E.g.: Value 10 in Hex = A).

Continued to: Microsoft Surface Applications - Deployment and Object Routing

Wednesday, May 06, 2009

Developing Microsoft Surface Applications

Continued from: Microsoft Surface Development Environment

Let us create a simple Surface Application to learn the development process.

Launch Visual Studio 2008 and create a new Surface project (File > New > Project > Visual C# > Surface > v1.0 > Surface Application (WPF))
The template will create all required files. Open the SurfaceWindow1.xaml file and following controls to it:

<s:SurfaceButton DockPanel.Dock="Bottom"
Content="Click Me"
Click="uxButton_Click" />
<s:ScatterView x:Name="uxScatterView"

We have just added Surface version of the button and a new Surface specific control called ScatterView. The ScatterView control is the control that you should use when you have one or more UI elements that you want users to be able to move, rotate, or resize freely within a fixed area. It supports all these features without writing any extra code.

Now let us add the code to create ellipses and add them as ScatterView items in the button’s click handler:

private void uxButton_Click(object sender, RoutedEventArgs e)
Ellipse ell = new Ellipse();
ell.Height = 50;
ell.Width = 50;
ell.Fill = new SolidColorBrush(Colors.Red);

ScatterViewItem item = new ScatterViewItem();
item.Content = ell;
Now launch the Surface Simulator and run this application. The application will appear within the simulator. Keep clicking on the buttons to add items to the scatter view.

Note that the items get added to random positions. You can move and rotate the items with one finger. You can hold one finger to the edge of an item and use another finger to drag and then resize the item. Notice that the active item has a shadow effect and the shadow changes smoothly according to the items position. You can push the item to an edge with some speed and it will bounce back with smooth physics behavior.

All the Surface controls have contact events and this can be used to find the location of contact. Here is an example:

private void uxButton_ContactDown(object sender, ContactEventArgs e)
Point contactPosition = e.Contact.GetPosition(this);

For non-Surface controls, the contacts events can be attached like this:
<Canvas s:Contacts.ContactDown="Canvas_ContactDown" />

Using the combination of standard WPF controls and Surface special controls, it is possible to create multi-touch applications for Surface very easily.

Here are the list of Surface version of the standard controls:
  • SurfaceWindow
  • SurfaceButton
  • SurfaceInkCanvas
  • SurfaceSlider
  • SurfaceScrollViewer
  • SurfaceListBox
  • SurfaceTextBox
  • SurfacePasswordBox
  • SurfaceMenu
  • SurfaceContextMenu
  • SurfaceCheckBox
  • SurfaceRadioButton
And here is the list of Special Surface controls:
  • ScatterView
  • ScatterViewItem
  • TagVisualizer
  • TagVisualization
TagVisualizer helps in the use of tagged objects and can be used to show a visual when a tag is placed on the Surface unit.

Continued to Microsoft Surface Tagged Objects and Tag Visualizations