Contact grouping and gesture recognition for surface computing

A surface computing system comprising:

• at least one instance of processing hardware;
• at least one bus system in communication with the processing hardware;
• at least one computer-readable storage medium that is not a sign in communication with the processing hardware via the bus system, comprising storage having computer-executable instructions stored thereon that, when loaded into the processing hardware, transform the processing hardware to
• receive at least one indication of a physical action directed by at least one user toward the surface computing system, wherein the physical action is represented by a plurality of contact points that correspond to a plurality of fingers associated with the user;
• associate respective velocity and position parameters with the plurality of contact points;
• select two of the plurality of contact points having a maximum velocity differential therebetween;
• associate a first one of the selected contact points with a first virtual hand data structure;
• associate a second one of the selected contact points with a second virtual hand data structure;
• assign the velocity and position parameters of the first selected contact point to the first virtual hand structure;
• assign the velocity and position parameters of the second selected contact point to the second virtual hand structure;
• and
• calculate a gesture represented by the physical action, based on relative movement between the first and second virtual hand structures as indicated by analysis of the first and second contact points.

A computer-implemented method comprising performing computer-implemented operations for:

• receiving at least one indication of a physical action directed by at least one user toward a surface computing system, wherein the physical action comprises a plurality of fingers of the at least one user being in physical contact with the surface computing system to interact with a software application program being presented on the surface computing system and, as a result, each of the plurality of fingers being interpreted by the surface computing system as a contact point of a plurality of contact points;
• associating respective velocity parameters with the plurality of contact points;
• calculating differentials between velocity parameters associated with pairs of the plurality contact points;
• selecting a first contact point of the plurality of contact points and a second contact point of the plurality of contact points to identify a pair of contact points having a greatest differential in velocity and thereby separately identifying the first contact point as being associated with a first actual hand of the at least one user and the second contact point as being associated with a second actual hand of the at least one user, the first contact point having a first contact point velocity parameter and the second contact point having a second contact point velocity parameter;
• associating the first contact point with a first virtual hand data structure that is representative of the first actual hand;
• associating the second contact point with a second virtual hand data structure that is representative of the second actual hand;
• assigning the first contact point velocity parameter to the first virtual hand data structure;
• assigning the second contact point velocity parameter to the second virtual hand data structure;
• associating a first remainder of the plurality of contact points with the first virtual hand data structure;
• and
• associating a second remainder of the plurality of contact points with the second virtual hand data structure.