#!/bin/csh -f

 # RCSid: $Id: pveil.csh,v 3.4 2008/11/10 19:08:19 greg Exp $

 #

 # Add veiling glare to picture

 #

 if ($#argv != 1) then

 	echo "Usage: $0 input.hdr > output.hdr"

 	exit 1

 endif

 set ifile=$1

 set td=/tmp

 set gf=$td/av$$.gs

 set cf=$td/av$$.cal

 set tf=($gf $cf)

 onintr quit

 findglare -r 400 -c -p $ifile \

 	| sed -e '1,/^BEGIN glare source$/d' -e '/^END glare source$/,$d' \

 	> $gf

 if ( -z $gf ) then

 	cat $ifile

 	goto quit

 endif

 ( rcalc -e '$1=recno;$2=$1;$3=$2;$4=$3;$5=$4*$5' $gf \

 	| tabfunc SDx SDy SDz I ; cat ) > $cf << '_EOF_'

 N : I(0);

 K : 9.2;	{ should be 9.6e-3/PI*(180/PI)^2 == 10.03 ? }

 bound(a,x,b) : if(a-x, a, if(x-b, b, x));

 Acos(x) : acos(bound(-1,x,1));

 sq(x) : x*x;

 mul(ct) : if(ct-cos(.5*PI/180), K/sq(.5), K/sq(180/PI)*ct/sq(Acos(ct)));

 Dx1 = Dx(1); Dy1 = Dy(1); Dz1 = Dz(1);		{ minor optimization }

 cosa(i) = SDx(i)*Dx1 + SDy(i)*Dy1 + SDz(i)*Dz1;

 sum(i) = if(i-.5, mul(cosa(i))*I(i)+sum(i-1), 0);

 veil = le(1)/WE * sum(N);

 ro = ri(1) + veil;

 go = gi(1) + veil;

 bo = bi(1) + veil;

 '_EOF_'

 getinfo < $ifile | egrep '^((VIEW|EXPOSURE|PIXASPECT|PRIMARIES|COLORCORR)=|[^ ]*(rpict|rview|pinterp) )'

 pcomb -f $cf $ifile

 quit:

 rm -f $tf