1 files changed, 30 insertions, 0 deletions
diff --git a/sys/imio/imloop.x b/sys/imio/imloop.x
new file mode 100644
index 00000000..ffae877b
--- /dev/null
+++ b/sys/imio/imloop.x
@@ -0,0 +1,30 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<imio.h>
+
+# IMLOOP -- Increment the vector V from VS to VE (nested do loops cannot
+# be used because of the variable number of dimensions).  Return LOOP_DONE
+# when V exceeds VE.
+
+int procedure imloop (v, vs, ve, vinc, ndim)
+
+long	v[ndim], vs[ndim], ve[ndim], vinc[ndim]
+int	ndim, dim
+
+begin
+	for (dim=2;  dim <= ndim;  dim=dim+1) {
+	    v[dim] = v[dim] + vinc[dim]
+
+	    if ((vinc[dim] > 0 && v[dim] - ve[dim] > 0) ||
+	        (vinc[dim] < 0 && ve[dim] - v[dim] > 0)) {
+
+		    if (dim < ndim)
+		        v[dim] = vs[dim]		# advance to next dim
+		    else
+		        break
+	    } else
+		return (LOOP_AGAIN)
+	}
+
+	return (LOOP_DONE)
+end