There are two ways to work with multiple touch point that come to mind when developing multi-touch applications. One is to attach TouchEvents to the objects which are applied to the stage. The other is to use the array of blobs to build interaction between the blob points. In this tutorial I'd like to go over a basic setup you can use to communicate through the blob array, by drawing lines through all of the blobs that a activated on the stage. This app is built using the Touchlib classes for multi-touch communication with tBeta or Touchlib via FLOSC.

If you do not have the needed Touchlib files, you can find them here: http://code.google.com/p/touchlib/
by downloading touchlib-src-win32-20071106.zip from the download page, or downloading the source code via SVN in the Source section.

So begin with creating a new folder, i named mine "blobLines" and create a new Flash file, which I've named blogLines.fla
Then create another folder named "BlobsFunction" (this is case sensitive) in the "blobLines" folder, this will contain the AS file of the application.

Find the folder labeled "flash" from the Touchlib files, normally found in /AS3/int/
And copy this folder to your "blobLines" folder. This contains the TUIO classes needed for Flash to communicate with tBeta and Touchlib via FLOSC.

So now your "blobLines" folder should have: blogLines.fla, a folder labeled "flash" and a folder labeled "BlobsFunction"

Open the Flash file and set size setting to you screen's resolution, I use a 1024x768 size display, and change your framerate to 30fps.
Now open a new file, and create a new Actionscript file. Save as... BlobLines.as (this is case sensitive) Read the rest of this entry »