storing respective first touch data for a first set of nodes at a first cycle;

determining a first total touch data by summing the respective first touch data for the first set of nodes at the first cycle;

storing respective second touch data for a second set of nodes at a second cycle after the first cycle, wherein the first set of nodes and the second set of nodes at least partially overlap;

allocating nodes for which first touch data was stored at the first cycle to a first touch;

allocating nodes for which second touch data was stored at the second cycle, but for which first touch data was not stored at the first cycle, to a second touch;

determining, for one or more boundary nodes of the first set of nodes allocated to the first touch that are adjacent to a node allocated to the second touch, whether the second touch data of the respective one or more boundary nodes is greater than the first touch data of the respective one or more boundary nodes;

re-allocating one or more of the respective boundary nodes to the second touch based on the second touch data of the respective one or more boundary nodes being greater than the first touch data of the respective one or more boundary nodes;

identifying one or more isolated nodes allocated to the second touch that are adjacent to at least one other node allocated to the first touch, and not adjacent to any other nodes allocated to the second touch, and re-allocating the one or more identified isolated nodes to the first touch;

after the one or more isolated nodes is reallocated to the first touch, and after the one or more boundary nodes is re-allocated to the second touch, determining a second total touch data by summing respective second touch data from the second cycle for nodes allocated to the first touch;

comparing the first total touch data to the second total touch data; and

identifying joint boundary nodes based on the comparison of the first total touch data to the second total touch data.