BSD 4_2 release

[unix-history] / usr / src / usr.lib / libplot / t300s / line.c

#ifndef lint
static char sccsid[] = "@(#)line.c      4.1 (Berkeley) 6/27/83";
#endif

#include "con.h"
line(x0,y0,x1,y1){
       iline(xconv(xsc(x0)),yconv(ysc(y0)),xconv(xsc(x1)),yconv(ysc(y1)));
       return;
}
cont(x0,y0){
       iline(xnow,ynow,xconv(xsc(x0)),yconv(ysc(y0)));
       return;
}
iline(cx0,cy0,cx1,cy1){
       int maxp,tt,j,np;
       char chx,chy,command;
           float xd,yd;
       float dist2(),sqrt();
       movep(cx0,cy0);
       maxp = sqrt(dist2(cx0,cy0,cx1,cy1))/2.;
       xd = cx1-cx0;
       yd = cy1-cy0;
       command = COM|((xd<0)<<1)|(yd<0);
       if(maxp == 0){
               xd=0;
               yd=0;
       }
       else {
               xd /= maxp;
               yd /= maxp;
       }
       inplot();
       spew(command);
       for (tt=0; tt<=maxp; tt++){
               chx= cx0+xd*tt-xnow;
               xnow += chx;
               chx = abval(chx);
               chy = cy0+yd*tt-ynow;
               ynow += chy;
               chy = abval(chy);
               spew(ADDR|chx<<3|chy);
       }
       outplot();
       return;
}