ref: 6b8eb26a267808c5ebcb6ec38f0b4806c54c5d6f dir: /sys/src/cmd/plot/libplot/erase.c/
#include "mplot.h" void erase(void){ m_swapbuf(); m_clrwin(clipminx, clipminy, clipmaxx, clipmaxy, e1->backgr); }