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SingularityViewer/indra/llcommon/llcriticaldamp.h
2017-03-14 01:44:26 -05:00

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/**
* @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
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*
* ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
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* $/LicenseInfo$
*/
#ifndef LL_LLCRITICALDAMP_H
#define LL_LLCRITICALDAMP_H
#include <vector>
#include "llframetimer.h"
#include "llunits.h"
class LL_COMMON_API LLSmoothInterpolation
{
public:
LLSmoothInterpolation();
// MANIPULATORS
static void updateInterpolants();
// ACCESSORS
static F32 getInterpolant(F32SecondsImplicit time_constant, bool use_cache = true);
template<typename T>
static T lerp(T a, T b, F32SecondsImplicit time_constant, bool use_cache = true)
{
F32 interpolant = getInterpolant(time_constant, use_cache);
return ((a * (1.f - interpolant))
+ (b * interpolant));
}
protected:
static F32 calcInterpolant(F32 time_constant);
struct CompareTimeConstants;
static LLFrameTimer sInternalTimer; // frame timer for calculating deltas
struct Interpolant
{
F32 mTimeScale;
F32 mInterpolant;
};
typedef std::vector<Interpolant> interpolant_vec_t;
static interpolant_vec_t sInterpolants;
static F32 sTimeDelta;
};
typedef LLSmoothInterpolation LLCriticalDamp;
#endif // LL_LLCRITICALDAMP_H