ref: edd3be53e7dc7b3362b4f1af86788a8fcae8b4fb dir: /sys/src/cmd/plot/libplot/box.c/
#include "mplot.h" void box(double x0, double y0, double x1, double y1){ move(x0, y0); vec(x0, y1); vec(x1, y1); vec(x1, y0); vec(x0, y0); }