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.