Initial commit

1 files changed, 34 insertions, 0 deletions

diff --git a/pkg/xtools/ranges/rginverse.x b/pkg/xtools/ranges/rginverse.x
new file mode 100644
index 00000000..869fde19
--- /dev/null
+++ b/pkg/xtools/ranges/rginverse.x
@@ -0,0 +1,34 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<pkg/rg.h>
+
+# RG_INVERSE -- Invert a set of ordered and merged ranges.
+
+procedure rg_inverse (rg, rmin, rmax)
+
+pointer	rg			# RANGES pointer
+int	rmin			# Minimum value of window
+int	rmax			# Maximum value of window
+
+int	i
+pointer rgtmp
+
+pointer	rg_window()
+
+begin
+	call malloc (rgtmp, LEN_RG + 2 * (RG_NRGS(rg) + 1), TY_STRUCT)
+	RG_NRGS(rgtmp) = RG_NRGS(rg) + 1
+
+	RG_X1(rgtmp, 1) = rmin
+
+	do i = 1, RG_NRGS(rg) {
+	    RG_X2(rgtmp, i) = RG_X1(rg, i) - 1
+	    RG_X1(rgtmp, i+1) = RG_X2(rg, i) + 1
+	}
+
+	RG_X2(rgtmp, RG_NRGS(rgtmp)) = rmax
+
+	call rg_free (rg)
+	rg = rg_window (rgtmp, rmin, rmax)
+	call rg_free (rgtmp)
+end