ref: a6a0bd3d6a567dc08f65c5d3aeb4c2af27e910cf dir: /sys/src/cmd/plot/libplot/erase.c/
#include "mplot.h" void erase(void){ m_swapbuf(); m_clrwin(clipminx, clipminy, clipmaxx, clipmaxy, e1->backgr); }