The DDA algorithm runs rather slowly because it requires real arithmetic (floating-point operations). We now describe an improvement on this algorithm called Bresenham's algorithm, which uses only integer arithmetic, and runs significantly faster.

(Historical note: this algorithm was first formulated in 1965, for the control of a pen-plotter. Ref: Bresenham, J.E. 'Algorithm for computer control of a digital plotter', IBM Systems Journal, January 1965, pp. 25-30.)