mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-11 03:34:13 +00:00
02614f2f1a
Compilers optimise these back into shifts on architectures where shifts of negative integers work the same as mul/div, so this solves the UB without actually causing any performance issue.
53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
/* 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 2
|
|
* 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, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
*/
|
|
|
|
#ifndef COMMON_FRAC_H
|
|
#define COMMON_FRAC_H
|
|
|
|
#include "common/scummsys.h"
|
|
|
|
/**
|
|
* The precision of the fractional (fixed point) type we define below.
|
|
* Normally you should never have 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
|