1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
/* 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
|
