# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.

# ABLTK -- Vector boolean less than constant.  C[i], type INT, is set to 1 if
# A[i] is less than B, else C[i] is set to zero.

procedure abltk$t (a, b, c, npix)

PIXEL	a[ARB]
PIXEL	b
int	c[ARB]
int	npix
int	i
$if (datatype == x)
real	abs_b
$endif

begin
	# The case b==0 is perhaps worth optimizing.  On many machines this
	# will save a memory fetch.

	if (b == 0$f) {
	    $if (datatype == x)
	    call aclri (c, npix)
	    $else
	    do i = 1, npix
		if (a[i] < 0)
		    c[i] = 1
		else
		    c[i] = 0
	    $endif
	} else {
	    $if (datatype == x)
	    abs_b = abs (b)
	    $endif
	    do i = 1, npix
		$if (datatype == x)
		if (abs (a[i]) < abs_b)
		$else
		if (a[i] < b)
		$endif
		    c[i] = 1
		else
		    c[i] = 0
	}
end