Files
simgear/simgear/math/interpolater.hxx
T
frohlich a3bc2eb836 Modified Files:
simgear/math/interpolater.cxx simgear/math/interpolater.hxx
	simgear/props/condition.cxx simgear/props/condition.hxx
	simgear/scene/model/animation.cxx
	simgear/scene/model/animation.hxx: Optimize interpolation table
	lookup by using a std::map.
2006-11-21 18:44:54 +00:00

94 lines
2.4 KiB
C++

/**
* \file interpolater.hxx
* Routines to handle linear interpolation from a table of x,y The
* table must be sorted by "x" in ascending order
*/
// Written by Curtis Olson, started April 1998.
//
// Copyright (C) 1998 Curtis L. Olson - http://www.flightgear.org/~curt
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// 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
// Library General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#ifndef _INTERPOLATER_H
#define _INTERPOLATER_H
#ifndef __cplusplus
# error This library requires C++
#endif
#include <simgear/compiler.h>
#include "simgear/structure/SGReferenced.hxx"
#include <map>
#include STL_STRING
SG_USING_STD(string);
/**
* A class that provids a simple linear 2d interpolation lookup table.
* The actual table is expected to be loaded from a file. The
* independant variable must be strictly ascending. The dependent
* variable can be anything.
*/
class SGInterpTable : public SGReferenced {
public:
/**
* Constructor. Creates a new, empty table.
*/
SGInterpTable();
/**
* Constructor. Loads the interpolation table from the specified file.
* @param file name of interpolation file
*/
SGInterpTable( const string& file );
/**
* Add an entry to the table, extending the table's length.
*
* @param ind The independent variable.
* @param dep The dependent variable.
*/
void addEntry (double ind, double dep);
/**
* Given an x value, linearly interpolate the y value from the table.
* @param x independent variable
* @return interpolated dependent variable
*/
double interpolate(double x) const;
/** Destructor */
~SGInterpTable();
private:
typedef std::map<double, double> Table;
Table _table;
};
#endif // _INTERPOLATER_H