# patch ---- copy a patch of information from a wall into a window.
#
subroutine patch(          conj,add, j1,j2, k1,k2, wall, n1,n2, wind, w1,w2)
integer i1,i2,s1,s2,d1,d2, conj,add, j1,j2, k1,k2,       n1,n2,       w1,w2
real                                               wall( n1,n2),wind( w1,w2)
call conjnull(             conj,add,               wall, n1*n2, wind, w1*w2)

if( k2 != 1) {  s2 = 1.5 + (n2 - w2) * (j2-1.)/(k2-1.)}    else { s2= 1}
if( k1 != 1) {  s1 = 1.5 + (n1 - w1) * (j1-1.)/(k1-1.)}    else { s1= 1}

do i2= 1, w2 {	d2= i2 + s2 - 1
do i1= 1, w1 {	d1= i1 + s1 - 1
	if( conj == 0 )
		wind( i1,i2) = wind( i1,i2) + wall( d1,d2)
	else
		wall( d1,d2) = wall( d1,d2) + wind( i1,i2)
	}}
return;	end