Initial commit

1 files changed, 72 insertions, 0 deletions

diff --git a/sys/imfort/imgs3r.x b/sys/imfort/imgs3r.x
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--- /dev/null
+++ b/sys/imfort/imgs3r.x
@@ -0,0 +1,72 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<imhdr.h>
+include	"imfort.h"
+
+# IMGS3R -- Get a section 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 imgs3r (im, buf, i1, i2, j1, j2, k1, k2, ier)
+
+pointer	im			# image descriptor
+real	buf[ARB]		# user data buffer
+int	i1, i2			# first, last column
+int	j1, j2			# line numbers
+int	k1, k2			# band numbers
+int	ier
+
+long	offset
+int	nchars, npix, j, k, op
+int	bfread()
+
+begin
+	# Verify in bounds.
+	if (i1 < 1 || i2 > IM_LEN(im,1) || i1 > i2) {
+	    ier = IE_XOOB
+	    call im_seterrim (ier, im)
+	    return
+	} else if (j1 < 1 || j2 > IM_LEN(im,2) || j1 > j2) {
+	    ier = IE_YOOB
+	    call im_seterrim (ier, im)
+	    return
+	} else if (k1 < 1 || k2 > IM_LEN(im,3) || k1 > k2) {
+	    ier = IE_ZOOB
+	    call im_seterrim (ier, im)
+	    return
+	} else if (IM_PIXTYPE(im) != TY_SHORT && IM_PIXTYPE(im) != TY_REAL) {
+	    ier = IE_PIXTYPE
+	    call im_seterrim (ier, im)
+	    return
+	}
+
+	npix = i2 - i1 + 1
+	nchars = npix * IM_SZPIXEL(im)
+	op = 1
+
+	do k = k1, k2 {
+	    do j = j1, j2 {
+		# Compute offset into pixel file.
+		offset = IM_PIXOFF(im) + (i1-1) * IM_SZPIXEL(im) +
+		    ((k-1) * IM_LEN(im,2) + (j-1)) * IM_LINESIZE(im)
+
+		# Read one line of data.
+		if (nchars != bfread (IM_PIXFP(im), buf[op], nchars, offset)) {
+		    ier = IE_RDPIX
+		    call im_seterrim (ier, im)
+		    return
+		}
+
+		# Swap bytes if necessary.
+		call imswap (im, buf[op], nchars)
+
+		# Convert the datatype if necessary.
+		if (IM_PIXTYPE(im) == TY_SHORT)
+		    call achtsr (buf[op], buf[op], npix)
+
+		op = op + npix
+	    }
+	}
+
+	ier = OK
+end