Fawkes API
Fawkes Development Version
sinusoidal.cpp
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/***************************************************************************
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* sinusoidal.cpp - Sinusoidal interpolator
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*
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* Created: Tue Nov 18 11:27:44 2008
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* Copyright 2008 Tim Niemueller [www.niemueller.de]
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* 2008 Graeme McPhillips
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* 2008 Stephen Marais
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*
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****************************************************************************/
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/* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version. A runtime exception applies to
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* this software (see LICENSE.GPL_WRE file mentioned below for details).
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*
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* This program 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
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* GNU Library General Public License for more details.
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*
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* Read the full text in the LICENSE.GPL_WRE file in the doc directory.
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*/
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#include <utils/math/interpolation/sinusoidal.h>
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#include <cmath>
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namespace
fawkes
{
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/** @class SinusoidalInterpolator <utils/math/interpolation/linear.h>
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* Sinusoidal value interpolator.
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* The interpolator creates intermediate points given a starting and and
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* end point and time constraints. Times are supplied in a discrete unit like
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* miliseconds or microseconds.
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* The values are interpolated on a sinusoidal curve with a slow start, the
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* greatest slope in the middle and then a slow down in the end. This
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* interpolation is useful for example for smooth servo movements.
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*
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* The calculation is executed with the following equation:
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* \f[
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* \left(\frac{1}{2} \sin\left(\frac{1}{2} + \frac{t_\mathrm{current}}{t_\mathrm{end}} \pi \right) + \frac{1}{2}\right) \cdot (v_\mathrm{end} - v_\mathrm{start}) + v_\mathrm{start}
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* \f]
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*
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* @author Tim Niemueller
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* @author Graeme McPhillips
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* @author Stephen Marais
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*/
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float
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SinusoidalInterpolator::interpolate
(
float
t_current,
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float
t_end,
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float
t_step,
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float
v_start,
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float
v_end)
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{
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return
(sin((-0.5 + (t_current / t_end)) * M_PI) / 2.0 + 0.5) * (v_end - v_start) + v_start;
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}
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}
// end namespace fawkes
fawkes::SinusoidalInterpolator::interpolate
virtual float interpolate(float t_current, float t_end, float t_step, float v_start, float v_end)
Definition:
sinusoidal.cpp:58
fawkes
src
libs
utils
math
interpolation
sinusoidal.cpp
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