aboutsummaryrefslogtreecommitdiff
path: root/sys/imio/tf/imgl1l.x
blob: a996ce3281e7a803e2a3820157a265ba3442f63e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.

include	<imhdr.h>
include	<imio.h>

# IMGL1? -- Get a line from an apparently one dimensional image.  If there
# is only one input buffer, no image section, we are not referencing out of
# bounds, and no datatype conversion needs to be performed, directly access
# the pixels to reduce the overhead per line.

pointer procedure imgl1l (im)

pointer	im
int	fd, nchars
long	offset
pointer	bp, imggsl(), freadp()
errchk	imopsf

begin
	repeat {
	    if (IM_FAST(im) == YES && IM_PIXTYPE(im) == TY_LONG) {
		fd = IM_PFD(im)
		if (fd == NULL) {
		    call imopsf (im)
		    next
		}

		offset = IM_PIXOFF(im)
		nchars = IM_PHYSLEN(im,1) * SZ_LONG
		ifnoerr (bp = (freadp (fd, offset, nchars) - 1) / SZ_LONG + 1)
		    return (bp)
	    }
	    return (imggsl (im, long(1), IM_LEN(im,1), 1))
	}
end