1. A method for waveform drawing, comprising: receiving an array of predecessor image data points, wherein the predecessor image data points form a predecessor line, comprising: a predecessor high end point; and a predecessor low end point; receiving an array of successor image data points, wherein the successor image data points form a successor line, comprising: a successor high end point; and a successor low end point; comparing the successor line to the predecessor line; and maintaining any portions of the predecessor line on a display that intersect with the successor line.