An improved parallel circle-drawing algorithm

When designing an algorithm for circle drawing, W.E. Wright (ibid., vol. 10, no. 5, pp. 60-7, Sept. 1990) chose to divide the circle into equal sub-arcs for rendering by separate processors. This method is simple and computationally tractable. Also, compared with the sequential algorithm, Wright's parallel circle-drawing algorithm achieves a speedup of 90% of P, where P represents the number of processors. We use an equal x-step division in this article to reformulate Wright's algorithm, which he regarded as unsatisfactory and messy. We show that this division method, which achieves a speedup of 100% of P, is not only computationally tractable but also requires no extra calculations.