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/**
* @file llcriticaldamp.h
* @brief A lightweight class that calculates critical damping constants once
* per frame.
*
* $LicenseInfo:firstyear=2002&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_LLCRITICALDAMP_H
#define LL_LLCRITICALDAMP_H
#include <vector>
#include "llframetimer.h"
#include "llunit.h"
class LL_COMMON_API LLSmoothInterpolation
{
public:
LLSmoothInterpolation();
// MANIPULATORS
static void updateInterpolants();
// ACCESSORS
static F32 getInterpolant(LLUnit<LLUnits::Seconds, F32> time_constant, bool use_cache = true);
template<typename T>
static T lerp(T a, T b, LLUnit<LLUnits::Seconds, F32> 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
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