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diff --git a/indra/llcommon/llsmoothstep.h b/indra/llcommon/llsmoothstep.h
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+/** 
+ * @file llsmoothstep.h
+ * @brief Smoothstep - transition from 0 to 1 - function, first and second derivatives all continuous (smooth)
+ *
+ * $LicenseInfo:firstyear=2001&license=viewergpl$
+ * 
+ * Copyright (c) 2001-2007, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlife.com/developers/opensource/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at http://secondlife.com/developers/opensource/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLSMOOTHSTEP_H
+#define LL_LLSMOOTHSTEP_H
+
+template <class LLDATATYPE>
+inline LLDATATYPE llsmoothstep(const LLDATATYPE& edge0, const LLDATATYPE& edge1, const LLDATATYPE& value)
+{
+    if (value < edge0)
+		return (LLDATATYPE)0;
+
+	if (value >= edge1)
+		return (LLDATATYPE)1;
+
+	// Scale/bias into [0..1] range
+	LLDATATYPE scaled_value = (value - edge0) / (edge1 - edge0);
+
+	return scaled_value * scaled_value * (3 - 2 * scaled_value);
+}
+
+#endif // LL_LLSMOOTHSTEP_H