ref: 15d1425b276495a82621a8d075176a59a512cdf3
dir: /sys/src/cmd/plot/libplot/frame.c/
#include "mplot.h" void frame(double xs, double ys, double xf, double yf){ register double osidex, osidey; osidex = e1->sidex; osidey = e1->sidey; e1->left = e0->left + xs * e0->sidex; e1->bottom = e0->bottom + ys * e0->sidey; e1->sidex = (xf-xs)*e0->sidex; e1->sidey = (yf-ys)*e0->sidey; e1->scalex *= (e1->sidex / osidex); e1->scaley *= (e1->sidey / osidey); e1->quantum=e0->quantum/sqrt(e1->scalex*e1->scalex + e1->scaley*e1->scaley); if(e1->quantum < .01) e1->quantum = .01; }