Making the DDA run: two-dimensional ray traversal using runs and runs of runs

Iterative algorithms based on runs, and runs of runs are presented to calculate the cells of the two-dimensional lattice intersected by a line of real slope and intercept. The technique is applied to the problem of traversing a ray through a two-dimensional grid. Using runs or runs of runs provides a significant improvement in the efficiency of ray traversal for all but very short path lengths when compared to the DDA algorithm implemented using floating or fixed point arithmetic.