Parallel algorithms for interactive manipulation of digital terrain models

Algorithms are presented for data movement on the massively parallel processor (MPP) in support of pan and zoom functions over large data grids extending earlier work that demonstrated real-time performance of graphics functions on grids that were equal in size to the physical dimensions of the MPP. When the dimensions of a data grid exceed the processing array size, data are packed in the array memory. Windows of the total data grid are interactively selected for processing. Movement of packed data is needed to distribute items across the array for efficient parallel processing. Execution time for data movement is found to exceed that for arithmetic aspects of graphics functions. Performance figures are given for routines written in MPP Pascal