/*                                                                            */
/* this script does the shift/rotation usually done in sort4migvxyz           */
/* the header words SrPtXC,SrPtYC,RcPtXC,RcPtYC,SrRcMX and SrRcMY are updated */
/* The old values of SrPtXC,SrPtYC,RcPtXC and RcPtYC are stored in            */
/* CDPBCX,CDPBCY,SrPrLt and SrPrLn                                            */
/* author: clarkera@bp.com                                                    */
/*                                                                            */
func Begin() {

/* here are the input parameters */
                  shift1x = 518942.562500;
                  shift1y = 6224729.500000;
                  shift2x = 0.000000;
                  shift2y = 0.000000;
                  angle = 9.257400;
                  angle = Pi / 180.0 * angle;
                  sn = sin(angle);
                  cs = cos(angle);
}

func OnLineHeader () {
  output(LH);
}

func OnTrace () {

                  sx = Tr.SrPtXC;
                  sy = Tr.SrPtYC;
                  rx = Tr.RcPtXC;
                  ry = Tr.RcPtYC;
                  
                  mx=sx-shift1x;
                  my=sy-shift1y;
                  sx= cs*mx+sn*my-shift2x;
                  sy=-sn*mx+cs*my-shift2y;
                  
                  mx=rx-shift1x;
                  my=ry-shift1y;
                  rx= cs*mx+sn*my-shift2x;
                  ry=-sn*mx+cs*my-shift2y;
                  
                  cmpx=(sx+rx)/2.0;
                  cmpy=(sy+ry)/2.0;

/* store the old header values in some unused header words */
                  Tr.CDPBCX = Tr.SrPtXC;
                  Tr.CDPBCY = Tr.SrPtYC;
                  Tr.SrPrLt = Tr.RcPtXC;
                  Tr.SrPrLn = Tr.RcPtYC;

                  Tr.SrPtXC = sx;
                  Tr.SrPtYC = sy;
                  Tr.RcPtXC = rx;
                  Tr.RcPtYC = ry;
                  Tr.SrRcMX = cmpx;
                  Tr.SrRcMY = cmpy;

                  output(Tr);
}