1. A non-transitory computer readable storage medium having computer-executable instructions stored therein, which when executed by an apparatus including a capacitive touch sensing surface processes information in a computing system by causing the apparatus to perform a method comprising: detecting a plurality of contacts corresponding to touch objects on or near the surface; in response to detecting the plurality of contacts, associating each contact with a different bit position in a bitfield; determining a motion of a first contact of the plurality of contacts from a first position on the surface to a second position on the surface; maintaining the association of each contact with the same bit position previously associated with the contact during the motion of the first contact from the first position on the surface to the second position on the surface, in maintaining the association each contact is associated with only a single bit position in the bitfield; and applying a bitmask to the bitfield to determine information of a set of one or more contacts of the plurality of contacts.