ref: f1400cfe8d0fc3dc0753d7f2b171a9df94c8ebfb dir: /sys/src/cmd/plot/libplot/erase.c/
#include "mplot.h" void erase(void){ m_swapbuf(); m_clrwin(clipminx, clipminy, clipmaxx, clipmaxy, e1->backgr); }