74 lines
2.1 KiB
C++
74 lines
2.1 KiB
C++
/**
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* @file llcriticaldamp.h
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* @brief A lightweight class that calculates critical damping constants once
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* per frame.
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*
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* $LicenseInfo:firstyear=2002&license=viewerlgpl$
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* Second Life Viewer Source Code
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* Copyright (C) 2010, Linden Research, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation;
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* version 2.1 of the License only.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
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* $/LicenseInfo$
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*/
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#ifndef LL_LLCRITICALDAMP_H
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#define LL_LLCRITICALDAMP_H
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#include <vector>
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#include "llframetimer.h"
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#include "llunit.h"
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class LL_COMMON_API LLSmoothInterpolation
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{
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public:
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LLSmoothInterpolation();
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// MANIPULATORS
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static void updateInterpolants();
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// ACCESSORS
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static F32 getInterpolant(LLUnit<LLUnits::Seconds, F32> time_constant, bool use_cache = true);
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template<typename T>
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static T lerp(T a, T b, LLUnit<LLUnits::Seconds, F32> time_constant, bool use_cache = true)
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{
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F32 interpolant = getInterpolant(time_constant, use_cache);
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return ((a * (1.f - interpolant))
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+ (b * interpolant));
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}
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protected:
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static F32 calcInterpolant(F32 time_constant);
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struct CompareTimeConstants;
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static LLFrameTimer sInternalTimer; // frame timer for calculating deltas
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struct Interpolant
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{
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F32 mTimeScale;
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F32 mInterpolant;
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};
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typedef std::vector<Interpolant> interpolant_vec_t;
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static interpolant_vec_t sInterpolants;
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static F32 sTimeDelta;
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};
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typedef LLSmoothInterpolation LLCriticalDamp;
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#endif // LL_LLCRITICALDAMP_H
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