leapFrame.js defines a function that helps you read and act on a single frame of leap data.
The leap device passes 'frames' of data as it sees objects in the world. A single frame of data has information on how many objects are seen, what direction they're pointing, where they're located in 3D space etc. Take time and look at leapFrame.js and the functions it provides:
- palm position
- palm direction
- palm normal vector
- finger position
- finger angle
- delta finger position
If you need some help figuring out what some of these vectors look like, take a look at the leap documentation, they have nice pictures showing all the axis etc.