include	<imhdr.h>

# AP_IMMAP -- Map an input image for the APEXTRACT package.

pointer procedure ap_immap (image, apaxis, dispaxis)

char	image[ARB]	# Image to map
int	apaxis		# Aperture axis
int	dispaxis	# Dispersion axis

pointer	im, immap()
int	i, j, imgeti(), clgeti()
errchk	immap

data	i/0/, j/0/

begin
	im = immap (image, READ_ONLY, 0)
	if (IM_NDIM(im) == 1) {
	    call imunmap (im)
	    call error (0, "Image must be two dimensional")
	} else if (IM_NDIM(im) > 2) {
	    if (i == 0)
	    call eprintf (
    "Warning: Image(s) are not two dimensional (ignoring higher dimensions)\n")
	    i = i + 1
	} else
	    i = 0

	iferr (dispaxis = imgeti (im, "dispaxis"))
	    dispaxis = clgeti ("dispaxis")
	if (dispaxis < 1 || dispaxis > 2) {
	    apaxis = dispaxis
	    dispaxis = max (1, min (2, clgeti ("dispaxis")))
	    if (j == 0) {
		call eprintf (
		    "WARNING: Dispersion axis %d invalid; using axis %d\n")
		    call pargi (apaxis)
		    call pargi (dispaxis)
	    }
	    j = j + 1
	} else
	    j = 0

	apaxis = mod (dispaxis, 2) + 1

	return (im)
end