Imported existing code

indra/llcommon/llcriticaldamp.h

@@ -0,0 +1,59 @@
+/** 
+ * @file llcriticaldamp.h
+ * @brief A lightweight class that calculates critical damping constants once
+ * per frame.  
+ *
+ * $LicenseInfo:firstyear=2002&license=viewergpl$
+ * 
+ * Copyright (c) 2002-2009, 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://secondlifegrid.net/programs/open_source/licensing/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://secondlifegrid.net/programs/open_source/licensing/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_LLCRITICALDAMP_H
+#define LL_LLCRITICALDAMP_H
+
+#include <map>
+
+#include "llframetimer.h"
+
+class LLCriticalDamp 
+{
+public:
+	LLCriticalDamp();
+
+	// MANIPULATORS
+	static void updateInterpolants();
+
+	// ACCESSORS
+	static F32 getInterpolant(const F32 time_constant, BOOL use_cache = TRUE);
+
+protected:	
+	static LLFrameTimer sInternalTimer;	// frame timer for calculating deltas
+
+	static std::map<F32, F32> 	sInterpolants;
+	static F32					sTimeDelta;
+};
+
+#endif  // LL_LLCRITICALDAMP_H