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-rw-r--r--sys/imfort/imgl3r.x56
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <imhdr.h>
+include "imfort.h"
+
+# IMGL3R -- Get a line from an image of type short or real. Automatic
+# datatype conversion from short to real is performed if necessary.
+# It is illegal to reference out of bounds.
+
+procedure imgl3r (im, buf, lineno, bandno, ier)
+
+pointer im # image descriptor
+real buf[ARB] # user data buffer
+int lineno # line number
+int bandno # band number
+int ier
+
+long offset
+int nchars, npix
+int bfread()
+
+begin
+ # Verify in bounds.
+ if (lineno < 1 || lineno > IM_LEN(im,2)) {
+ ier = IE_YOOB
+ call im_seterrim (ier, im)
+ return
+ } else if (bandno < 1 || bandno > IM_LEN(im,3)) {
+ ier = IE_ZOOB
+ call im_seterrim (ier, im)
+ return
+ }
+
+ npix = IM_LEN(im,1)
+ nchars = npix * IM_SZPIXEL(im)
+
+ # Compute offset into pixel file.
+ offset = IM_PIXOFF(im) +
+ ((bandno-1) * IM_LEN(im,2) + (lineno-1)) * IM_LINESIZE(im)
+
+ # Read one line of data.
+ if (nchars != bfread (IM_PIXFP(im), buf, nchars, offset)) {
+ ier = IE_RDPIX
+ call im_seterrim (ier, im)
+ return
+ }
+
+ # Swap bytes if necessary.
+ call imswap (im, buf, nchars)
+
+ # Convert the datatype if necessary.
+ if (IM_PIXTYPE(im) == TY_SHORT)
+ call achtsr (buf, buf, npix)
+
+ ier = OK
+end