ref: 59bd46cbf8814ab2a2b26df2a8c0f5481f40f6b4 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); }