1 files changed, 47 insertions, 0 deletions
diff --git a/sys/imio/tf/impl2l.x b/sys/imio/tf/impl2l.x
new file mode 100644
index 00000000..c42d57cf
--- /dev/null
+++ b/sys/imio/tf/impl2l.x
@@ -0,0 +1,47 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<syserr.h>
+include	<imhdr.h>
+include	<imio.h>
+
+# IMPL2? -- Put a line to an apparently two 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 impl2l (im, linenum)
+
+pointer	im			# image header pointer
+int	linenum			# line to be written
+
+int	fd, nchars
+long	vs[2], ve[2], offset
+pointer	bp, impgsl(), fwritep()
+errchk	imopsf, imerr
+
+begin
+	repeat {
+	    if (IM_FAST(im) == YES && IM_PIXTYPE(im) == TY_LONG) {
+		fd = IM_PFD(im)
+		if (fd == NULL) {
+		    call imopsf (im)
+		    next
+		}
+		if (linenum < 1 || linenum > IM_LEN(im,2))
+		    call imerr (IM_NAME(im), SYS_IMREFOOB)
+
+		offset = (linenum - 1) * IM_PHYSLEN(im,1) * SZ_LONG +
+		    IM_PIXOFF(im)
+		nchars = IM_PHYSLEN(im,1) * SZ_LONG
+		ifnoerr (bp = (fwritep (fd, offset, nchars) - 1) / SZ_LONG + 1)
+		    return (bp)
+	    }
+
+	    vs[1] = 1
+	    ve[1] = IM_LEN(im,1)
+	    vs[2] = linenum
+	    ve[2] = linenum
+
+	    return (impgsl (im, vs, ve, 2))
+	}
+end