Patently Apple reports that Apple has been granted a patent for a multi-touch system that compares finger arrangements at the beginning of multi-touch gestures and discriminates between neutral and spread-hand performances. Gestures by the neutral and spread-hand versions of each chord are then mapped to separate, but intuitively related cursor functions or sets of commands.
Less-frequently performed functions and commands are typically assigned to the spread-hand chord, since spreading the hand from neutral takes deliberate effort. With these neutral and spread distinctions, a two-handed gesture set can be packed into a one-handed touch surface, or for two-handed touch surfaces, twice as many intuitively customizable gesture command sets can be accommodated.