/*
 distfix_ufh is a script to compute trace distances and midpoint XYs
 based on source & receiver XYs.

 in a pipeline you run it as follows

 ... | ufh distfix_ufh | ...

 from disk files you run as follows

 ufh distfix_ufh < indata > outdata

*/
func OnLineHeader () {  /* read & write line header  */
	output (LH);
}

func OnTrace () {  /* process all traces */
/*
get src & srcvr XYs
*/
	srx = Tr.SrPtXC;
	sry = Tr.SrPtYC;
	rrx = Tr.RcPtXC;
	rry = Tr.RcPtYC;
/*
compute trace distance & store in trace header
*/
        dxt = srx - rrx;
        dyt = sry - rry;
        dist = sqrt ( dxt * dxt + dyt * dyt );
        Tr.DstSgn = dist + 0.5;
/*
compute CDP bin centers & store in trace header
*/
	mpx = (srx + rrx) / 2;
	mpy = (sry + rry) / 2;
	Tr.SrRcMX = mpx;
	Tr.SrRcMY = mpy;

	output (Tr);     /* output trace  */
}