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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef COMMON_FRAC_H
#define COMMON_FRAC_H
#include "common/scummsys.h"
/**
* @defgroup common_frac Fixed-point fractions
* @ingroup common
*
* @brief API for fixed-point fractions.
*
* @{
*/
/**
* The precision of the fractional (fixed-point) type that is defined below.
* Normally, you should never need to modify this value.
*/
enum {
FRAC_BITS = 16,
FRAC_LO_MASK = ((1L << FRAC_BITS) - 1),
FRAC_HI_MASK = ((1L << FRAC_BITS) - 1) << FRAC_BITS,
FRAC_ONE = (1L << FRAC_BITS), // 1.0
FRAC_HALF = (1L << (FRAC_BITS-1)) // 0.5
};
/**
* Fixed-point fractions, used by the sound rate converter and other code.
*/
typedef int32 frac_t;
inline frac_t doubleToFrac(double value) { return (frac_t)(value * FRAC_ONE); }
inline double fracToDouble(frac_t value) { return ((double)value) / FRAC_ONE; }
inline frac_t intToFrac(int16 value) { return value * (1 << FRAC_BITS); }
inline int16 fracToInt(frac_t value) { return value / (1 << FRAC_BITS); }
/** @} */
#endif
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