1 files changed, 71 insertions, 0 deletions
diff --git a/sys/plio/tf/plp2rl.x b/sys/plio/tf/plp2rl.x
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+++ b/sys/plio/tf/plp2rl.x
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<plset.h>
+include	<plio.h>
+
+# PL_P2R -- Convert a pixel array to a range list.  The length of the output
+# range list is returned as the function value.
+
+int procedure pl_p2rl (px_src, xs, rl, npix)
+
+long	px_src[ARB]		#I input pixel array
+int	xs			#I starting index in pixbuf
+long	rl[3,ARB]		#O destination range list
+int	npix			#I number of pixels to convert
+
+long	hi, pv, zero
+int	xe, x1, np, rn, nv, ip
+define	done_ 91
+
+begin
+	# No input pixels?
+	if (npix <= 0)
+	    return (0)
+
+	xe = xs + npix - 1
+	rn = RL_FIRST
+
+	# Pack the pixel array into a range list.  This is done by scanning
+	# the pixel list for successive ranges of pixels of constant nonzero
+	# value, where each range is described as follows:
+
+	zero = 0
+	pv = max (zero, px_src[xs])	# pixel value of current range
+	x1 = xs			# start index of current range
+	hi = 1			# current high value
+
+	# Process the data array.
+	do ip = xs, xe {
+	    if (ip < xe) {
+		# Get the next pixel value, loop again if same as previous one.
+		nv = max (zero, px_src[ip+1])
+		if (nv == pv)
+		    next
+
+		# If current range is zero, loop again to get nonzero range.
+		if (pv == 0) {
+		    pv = nv
+		    x1 = ip + 1
+		    next
+		}
+	    }
+
+	    np = ip - x1 + 1
+
+	    # Output the new range.
+	    if (pv > 0) {
+		rl[1,rn] = x1
+		rl[2,rn] = np
+		rl[3,rn] = pv
+		rn = rn + 1
+	    }
+
+	    x1 = ip + 1
+	    pv = nv
+	}
+
+	RL_LEN(rl) = rn - 1
+	RL_AXLEN(rl) = npix
+
+	return (rn - 1)
+end