ref: a20cc2d81463696a759b130f2d68f0d2f641075b
dir: /Game/src/audiolib/pitch.c/
/*
Copyright (C) 1994-1995 Apogee Software, Ltd.
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/**********************************************************************
module: PITCH.C
author: James R. Dose
date: June 14, 1993
Routines for pitch scaling.
(c) Copyright 1993 James R. Dose. All Rights Reserved.
**********************************************************************/
#include "pitch.h"
#define MAXDETUNE 25
static uint32_t PitchTable[ 12 ][ MAXDETUNE ] =
{
{ 0x10000, 0x10097, 0x1012f, 0x101c7, 0x10260, 0x102f9, 0x10392, 0x1042c,
0x104c6, 0x10561, 0x105fb, 0x10696, 0x10732, 0x107ce, 0x1086a, 0x10907,
0x109a4, 0x10a41, 0x10adf, 0x10b7d, 0x10c1b, 0x10cba, 0x10d59, 0x10df8,
0x10e98 },
{ 0x10f38, 0x10fd9, 0x1107a, 0x1111b, 0x111bd, 0x1125f, 0x11302, 0x113a5,
0x11448, 0x114eb, 0x1158f, 0x11634, 0x116d8, 0x1177e, 0x11823, 0x118c9,
0x1196f, 0x11a16, 0x11abd, 0x11b64, 0x11c0c, 0x11cb4, 0x11d5d, 0x11e06,
0x11eaf },
{ 0x11f59, 0x12003, 0x120ae, 0x12159, 0x12204, 0x122b0, 0x1235c, 0x12409,
0x124b6, 0x12563, 0x12611, 0x126bf, 0x1276d, 0x1281c, 0x128cc, 0x1297b,
0x12a2b, 0x12adc, 0x12b8d, 0x12c3e, 0x12cf0, 0x12da2, 0x12e55, 0x12f08,
0x12fbc },
{ 0x1306f, 0x13124, 0x131d8, 0x1328d, 0x13343, 0x133f9, 0x134af, 0x13566,
0x1361d, 0x136d5, 0x1378d, 0x13846, 0x138fe, 0x139b8, 0x13a72, 0x13b2c,
0x13be6, 0x13ca1, 0x13d5d, 0x13e19, 0x13ed5, 0x13f92, 0x1404f, 0x1410d,
0x141cb },
{ 0x1428a, 0x14349, 0x14408, 0x144c8, 0x14588, 0x14649, 0x1470a, 0x147cc,
0x1488e, 0x14951, 0x14a14, 0x14ad7, 0x14b9b, 0x14c5f, 0x14d24, 0x14dea,
0x14eaf, 0x14f75, 0x1503c, 0x15103, 0x151cb, 0x15293, 0x1535b, 0x15424,
0x154ee },
{ 0x155b8, 0x15682, 0x1574d, 0x15818, 0x158e4, 0x159b0, 0x15a7d, 0x15b4a,
0x15c18, 0x15ce6, 0x15db4, 0x15e83, 0x15f53, 0x16023, 0x160f4, 0x161c5,
0x16296, 0x16368, 0x1643a, 0x1650d, 0x165e1, 0x166b5, 0x16789, 0x1685e,
0x16934 },
{ 0x16a09, 0x16ae0, 0x16bb7, 0x16c8e, 0x16d66, 0x16e3e, 0x16f17, 0x16ff1,
0x170ca, 0x171a5, 0x17280, 0x1735b, 0x17437, 0x17513, 0x175f0, 0x176ce,
0x177ac, 0x1788a, 0x17969, 0x17a49, 0x17b29, 0x17c09, 0x17cea, 0x17dcc,
0x17eae },
{ 0x17f91, 0x18074, 0x18157, 0x1823c, 0x18320, 0x18406, 0x184eb, 0x185d2,
0x186b8, 0x187a0, 0x18888, 0x18970, 0x18a59, 0x18b43, 0x18c2d, 0x18d17,
0x18e02, 0x18eee, 0x18fda, 0x190c7, 0x191b5, 0x192a2, 0x19391, 0x19480,
0x1956f },
{ 0x1965f, 0x19750, 0x19841, 0x19933, 0x19a25, 0x19b18, 0x19c0c, 0x19d00,
0x19df4, 0x19ee9, 0x19fdf, 0x1a0d5, 0x1a1cc, 0x1a2c4, 0x1a3bc, 0x1a4b4,
0x1a5ad, 0x1a6a7, 0x1a7a1, 0x1a89c, 0x1a998, 0x1aa94, 0x1ab90, 0x1ac8d,
0x1ad8b },
{ 0x1ae89, 0x1af88, 0x1b088, 0x1b188, 0x1b289, 0x1b38a, 0x1b48c, 0x1b58f,
0x1b692, 0x1b795, 0x1b89a, 0x1b99f, 0x1baa4, 0x1bbaa, 0x1bcb1, 0x1bdb8,
0x1bec0, 0x1bfc9, 0x1c0d2, 0x1c1dc, 0x1c2e6, 0x1c3f1, 0x1c4fd, 0x1c609,
0x1c716 },
{ 0x1c823, 0x1c931, 0x1ca40, 0x1cb50, 0x1cc60, 0x1cd70, 0x1ce81, 0x1cf93,
0x1d0a6, 0x1d1b9, 0x1d2cd, 0x1d3e1, 0x1d4f6, 0x1d60c, 0x1d722, 0x1d839,
0x1d951, 0x1da69, 0x1db82, 0x1dc9c, 0x1ddb6, 0x1ded1, 0x1dfec, 0x1e109,
0x1e225 },
{ 0x1e343, 0x1e461, 0x1e580, 0x1e6a0, 0x1e7c0, 0x1e8e0, 0x1ea02, 0x1eb24,
0x1ec47, 0x1ed6b, 0x1ee8f, 0x1efb4, 0x1f0d9, 0x1f1ff, 0x1f326, 0x1f44e,
0x1f576, 0x1f69f, 0x1f7c9, 0x1f8f3, 0x1fa1e, 0x1fb4a, 0x1fc76, 0x1fda3,
0x1fed1 }
};
//static int PITCH_Installed = FALSE;
/*---------------------------------------------------------------------
Function: PITCH_Init
Initializes pitch table.
---------------------------------------------------------------------*/
/*
void PITCH_Init
(
void
)
{
int note;
int detune;
if ( !PITCH_Installed )
{
for( note = 0; note < 12; note++ )
{
for( detune = 0; detune < MAXDETUNE; detune++ )
{
PitchTable[ note ][ detune ] = 0x10000 *
pow( 2, ( note * MAXDETUNE + detune ) / ( 12.0 * MAXDETUNE ) );
}
}
PITCH_Installed = TRUE;
}
}
*/
/**********************************************************************
Memory locked functions:
**********************************************************************/
#define PITCH_LockStart PITCH_GetScale
/*---------------------------------------------------------------------
Function: PITCH_GetScale
Returns a fixed-point value to scale number the specified amount.
---------------------------------------------------------------------*/
uint32_t PITCH_GetScale
(
int pitchoffset
)
{
uint32_t scale;
int octaveshift;
int noteshift;
int note;
int detune;
// if ( !PITCH_Installed )
// {
// PITCH_Init();
// }
if ( pitchoffset == 0 )
{
return( PitchTable[ 0 ][ 0 ] );
}
noteshift = pitchoffset % 1200;
if ( noteshift < 0 )
{
noteshift += 1200;
}
note = noteshift / 100;
detune = ( noteshift % 100 ) / ( 100 / MAXDETUNE );
octaveshift = ( pitchoffset - noteshift ) / 1200;
if ( detune < 0 )
{
detune += ( 100 / MAXDETUNE );
note--;
if ( note < 0 )
{
note += 12;
octaveshift--;
}
}
scale = PitchTable[ note ][ detune ];
if ( octaveshift < 0 )
{
scale >>= -octaveshift;
}
else
{
scale <<= octaveshift;
}
return( scale );
}