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dbopl.cpp
1682 lines (1523 loc) · 46 KB
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dbopl.cpp
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/*
* Copyright (C) 2002-2021 The DOSBox Team
*
* 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.
*/
/*
DOSBox implementation of a combined Yamaha YMF262 and Yamaha YM3812 emulator.
Enabling the opl3 bit will switch the emulator to stereo opl3 output instead of regular mono opl2
Except for the table generation it's all integer math
Can choose different types of generators, using muls and bigger tables, try different ones for slower platforms
The generation was based on the MAME implementation but tried to have it use less memory and be faster in general
MAME uses much bigger envelope tables and this will be the biggest cause of it sounding different at times
//TODO Don't delay first operator 1 sample in opl3 mode
//TODO Maybe not use class method pointers but a regular function pointers with operator as first parameter
//TODO Fix panning for the Percussion channels, would any opl3 player use it and actually really change it though?
//TODO Check if having the same accuracy in all frequency multipliers sounds better or not
//DUNNO Keyon in 4op, switch to 2op without keyoff.
*/
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "dosbox.h"
#include "dbopl.h"
#ifndef PI
#define PI 3.14159265358979323846
#endif
namespace DBOPL {
#define OPLRATE ((double)(14318180.0 / 288.0))
#define TREMOLO_TABLE 52
//Try to use most precision for frequencies
//Else try to keep different waves in synch
//#define WAVE_PRECISION 1
#ifndef WAVE_PRECISION
//Wave bits available in the top of the 32bit range
//Original adlib uses 10.10, we use 10.22
#define WAVE_BITS 10
#else
//Need some extra bits at the top to have room for octaves and frequency multiplier
//We support to 8 times lower rate
//128 * 15 * 8 = 15350, 2^13.9, so need 14 bits
#define WAVE_BITS 14
#endif
#define WAVE_SH ( 32 - WAVE_BITS )
#define WAVE_MASK ( ( 1 << WAVE_SH ) - 1 )
//Use the same accuracy as the waves
#define LFO_SH ( WAVE_SH - 10 )
//LFO is controlled by our tremolo 256 sample limit
#define LFO_MAX ( 256 << ( LFO_SH ) )
//Maximum amount of attenuation bits
//Envelope goes to 511, 9 bits
#if (DBOPL_WAVE == WAVE_TABLEMUL )
//Uses the value directly
#define ENV_BITS ( 9 )
#else
//Add 3 bits here for more accuracy and would have to be shifted up either way
#define ENV_BITS ( 9 )
#endif
//Limits of the envelope with those bits and when the envelope goes silent
#define ENV_MIN 0
#define ENV_EXTRA ( ENV_BITS - 9 )
#define ENV_MAX ( 511 << ENV_EXTRA )
#define ENV_LIMIT ( ( 12 * 256) >> ( 3 - ENV_EXTRA ) )
#define ENV_SILENT( _X_ ) ( (_X_) >= ENV_LIMIT )
//Attack/decay/release rate counter shift
#define RATE_SH 24
#define RATE_MASK ( ( 1 << RATE_SH ) - 1 )
//Has to fit within 16bit lookuptable
#define MUL_SH 16
//Check some ranges
#if ENV_EXTRA > 3
#error Too many envelope bits
#endif
//How much to subtract from the base value for the final attenuation
static const uint8_t KslCreateTable[16] = {
//0 will always be lower than 7 * 8
64, 32, 24, 19,
16, 12, 11, 10,
8, 6, 5, 4,
3, 2, 1, 0,
};
#define M(_X_) ((uint8_t)( (_X_) * 2))
static const uint8_t FreqCreateTable[16] = {
M(0.5), M(1 ), M(2 ), M(3 ), M(4 ), M(5 ), M(6 ), M(7 ),
M(8 ), M(9 ), M(10), M(10), M(12), M(12), M(15), M(15)
};
#undef M
//We're not including the highest attack rate, that gets a special value
static const uint8_t AttackSamplesTable[13] = {
69, 55, 46, 40,
35, 29, 23, 20,
19, 15, 11, 10,
9
};
//On a real opl these values take 8 samples to reach and are based upon larger tables
static const uint8_t EnvelopeIncreaseTable[13] = {
4, 5, 6, 7,
8, 10, 12, 14,
16, 20, 24, 28,
32,
};
#if ( DBOPL_WAVE == WAVE_HANDLER ) || ( DBOPL_WAVE == WAVE_TABLELOG )
static uint16_t ExpTable[ 256 ];
#endif
#if ( DBOPL_WAVE == WAVE_HANDLER )
//PI table used by WAVEHANDLER
static uint16_t SinTable[ 512 ];
#endif
#if ( DBOPL_WAVE > WAVE_HANDLER )
//Layout of the waveform table in 512 entry intervals
//With overlapping waves we reduce the table to half its size
// | |//\\|____|WAV7|//__|/\ |____|/\/\|
// |\\//| | |WAV7| | \/| | |
// |06 |0126|17 |7 |3 |4 |4 5 |5 |
//6 is just 0 shifted and masked
static int16_t WaveTable[ 8 * 512 ];
//Distance into WaveTable the wave starts
static const uint16_t WaveBaseTable[8] = {
0x000, 0x200, 0x200, 0x800,
0xa00, 0xc00, 0x100, 0x400,
};
//Mask the counter with this
static const uint16_t WaveMaskTable[8] = {
1023, 1023, 511, 511,
1023, 1023, 512, 1023,
};
//Where to start the counter on at keyon
static const uint16_t WaveStartTable[8] = {
512, 0, 0, 0,
0, 512, 512, 256,
};
#endif
#if ( DBOPL_WAVE == WAVE_TABLEMUL )
static uint16_t MulTable[ 384 ];
#endif
static uint8_t KslTable[ 8 * 16 ];
static uint8_t TremoloTable[ TREMOLO_TABLE ];
//Start of a channel behind the chip struct start
static uint16_t ChanOffsetTable[32];
//Start of an operator behind the chip struct start
static uint16_t OpOffsetTable[64];
//The lower bits are the shift of the operator vibrato value
//The highest bit is right shifted to generate -1 or 0 for negation
//So taking the highest input value of 7 this gives 3, 7, 3, 0, -3, -7, -3, 0
static const int8_t VibratoTable[ 8 ] = {
1 - 0x00, 0 - 0x00, 1 - 0x00, 30 - 0x00,
1 - 0x80, 0 - 0x80, 1 - 0x80, 30 - 0x80
};
//Shift strength for the ksl value determined by ksl strength
static const uint8_t KslShiftTable[4] = {
31,1,2,0
};
//Generate a table index and table shift value using input value from a selected rate
static void EnvelopeSelect( uint8_t val, uint8_t& index, uint8_t& shift ) {
if ( val < 13 * 4 ) { //Rate 0 - 12
shift = 12 - ( val >> 2 );
index = val & 3;
} else if ( val < 15 * 4 ) { //rate 13 - 14
shift = 0;
index = val - 12 * 4;
} else { //rate 15 and up
shift = 0;
index = 12;
}
}
#if ( DBOPL_WAVE == WAVE_HANDLER )
/*
Generate the different waveforms out of the sine/exponential table using handlers
*/
static /*inline*/ Bits MakeVolume( Bitu wave, Bitu volume ) {
Bitu total = wave + volume;
Bitu index = total & 0xff;
Bitu sig = ExpTable[ index ];
Bitu exp = total >> 8;
#if 0
//Check if we overflow the 31 shift limit
if ( exp >= 32 ) {
LOG_MSG( "WTF %d %d", total, exp );
}
#endif
return (sig >> exp);
};
static Bits DB_FASTCALL WaveForm0( Bitu i, Bitu volume ) {
Bits neg = 0 - (( i >> 9) & 1);//Create ~0 or 0
Bitu wave = SinTable[i & 511];
return (MakeVolume( wave, volume ) ^ neg) - neg;
}
static Bits DB_FASTCALL WaveForm1( Bitu i, Bitu volume ) {
uint32_t wave = SinTable[i & 511];
wave |= ( ( (i ^ 512 ) & 512) - 1) >> ( 32 - 12 );
return MakeVolume( wave, volume );
}
static Bits DB_FASTCALL WaveForm2( Bitu i, Bitu volume ) {
Bitu wave = SinTable[i & 511];
return MakeVolume( wave, volume );
}
static Bits DB_FASTCALL WaveForm3( Bitu i, Bitu volume ) {
Bitu wave = SinTable[i & 255];
wave |= ( ( (i ^ 256 ) & 256) - 1) >> ( 32 - 12 );
return MakeVolume( wave, volume );
}
static Bits DB_FASTCALL WaveForm4( Bitu i, Bitu volume ) {
//Twice as fast
i <<= 1;
Bits neg = 0 - (( i >> 9) & 1);//Create ~0 or 0
Bitu wave = SinTable[i & 511];
wave |= ( ( (i ^ 512 ) & 512) - 1) >> ( 32 - 12 );
return (MakeVolume( wave, volume ) ^ neg) - neg;
}
static Bits DB_FASTCALL WaveForm5( Bitu i, Bitu volume ) {
//Twice as fast
i <<= 1;
Bitu wave = SinTable[i & 511];
wave |= ( ( (i ^ 512 ) & 512) - 1) >> ( 32 - 12 );
return MakeVolume( wave, volume );
}
static Bits DB_FASTCALL WaveForm6( Bitu i, Bitu volume ) {
Bits neg = 0 - (( i >> 9) & 1);//Create ~0 or 0
return (MakeVolume( 0, volume ) ^ neg) - neg;
}
static Bits DB_FASTCALL WaveForm7( Bitu i, Bitu volume ) {
//Negative is reversed here
Bits neg = (( i >> 9) & 1) - 1;
Bitu wave = (i << 3);
//When negative the volume also runs backwards
wave = ((wave ^ neg) - neg) & 4095;
return (MakeVolume( wave, volume ) ^ neg) - neg;
}
static const WaveHandler WaveHandlerTable[8] = {
WaveForm0, WaveForm1, WaveForm2, WaveForm3,
WaveForm4, WaveForm5, WaveForm6, WaveForm7
};
#endif
/*
Operator
*/
//We zero out when rate == 0
/*inline*/ void Operator::UpdateAttack( const Chip* chip ) {
uint8_t rate = reg60 >> 4;
if ( rate ) {
uint8_t val = (rate << 2) + ksr;
attackAdd = chip->attackRates[ val ];
rateZero &= ~(1 << ATTACK);
} else {
attackAdd = 0;
rateZero |= (1 << ATTACK);
}
}
/*inline*/ void Operator::UpdateDecay( const Chip* chip ) {
uint8_t rate = reg60 & 0xf;
if ( rate ) {
uint8_t val = (rate << 2) + ksr;
decayAdd = chip->linearRates[ val ];
rateZero &= ~(1 << DECAY);
} else {
decayAdd = 0;
rateZero |= (1 << DECAY);
}
}
/*inline*/ void Operator::UpdateRelease( const Chip* chip ) {
uint8_t rate = reg80 & 0xf;
if ( rate ) {
uint8_t val = (rate << 2) + ksr;
releaseAdd = chip->linearRates[ val ];
rateZero &= ~(1 << RELEASE);
if ( !(reg20 & MASK_SUSTAIN ) ) {
rateZero &= ~( 1 << SUSTAIN );
}
} else {
rateZero |= (1 << RELEASE);
releaseAdd = 0;
if ( !(reg20 & MASK_SUSTAIN ) ) {
rateZero |= ( 1 << SUSTAIN );
}
}
}
/*inline*/ void Operator::UpdateAttenuation( ) {
uint8_t kslBase = (uint8_t)((chanData >> SHIFT_KSLBASE) & 0xff);
uint32_t tl = reg40 & 0x3f;
uint8_t kslShift = KslShiftTable[ reg40 >> 6 ];
//Make sure the attenuation goes to the right bits
totalLevel = (int32_t)(tl << ( ENV_BITS - 7 )); //Total level goes 2 bits below max
totalLevel += ( kslBase << ENV_EXTRA ) >> kslShift;
}
void Operator::UpdateFrequency( ) {
uint32_t freq = chanData & (( 1 << 10 ) - 1);
uint32_t block = (chanData >> 10) & 0xff;
#ifdef WAVE_PRECISION
block = 7u - block;
waveAdd = ( freq * freqMul ) >> block;
#else
waveAdd = ( freq << block ) * freqMul;
#endif
if ( reg20 & MASK_VIBRATO ) {
vibStrength = (uint8_t)(freq >> 7u);
#ifdef WAVE_PRECISION
vibrato = ( (Bitu)vibStrength * freqMul ) >> block;
#else
vibrato = ( (Bitu)vibStrength << block ) * freqMul;
#endif
} else {
vibStrength = 0;
vibrato = 0;
}
}
void Operator::UpdateRates( const Chip* chip ) {
//Mame seems to reverse this where enabling ksr actually lowers
//the rate, but pdf manuals says otherwise?
uint8_t newKsr = (uint8_t)((chanData >> SHIFT_KEYCODE) & 0xff);
if ( !( reg20 & MASK_KSR ) ) {
newKsr >>= 2;
}
if ( ksr == newKsr )
return;
ksr = newKsr;
UpdateAttack( chip );
UpdateDecay( chip );
UpdateRelease( chip );
}
/*INLINE*/ int32_t Operator::RateForward( uint32_t add ) {
rateIndex += add;
int32_t ret = (int32_t)(rateIndex >> RATE_SH);
rateIndex = rateIndex & RATE_MASK;
return ret;
}
template< Operator::State yes>
Bits Operator::TemplateVolume( ) {
int32_t vol = volume;
int32_t change;
switch ( yes ) {
case OFF:
return ENV_MAX;
case ATTACK:
change = RateForward( attackAdd );
if ( !change )
return vol;
vol += ( (~vol) * change ) >> 3;
if ( vol < ENV_MIN ) {
volume = ENV_MIN;
rateIndex = 0;
SetState( DECAY );
return ENV_MIN;
}
break;
case DECAY:
vol += RateForward( decayAdd );
if ( GCC_UNLIKELY(vol >= sustainLevel) ) {
//Check if we didn't overshoot max attenuation, then just go off
if ( GCC_UNLIKELY(vol >= ENV_MAX) ) {
volume = ENV_MAX;
SetState( OFF );
return ENV_MAX;
}
//Continue as sustain
rateIndex = 0;
SetState( SUSTAIN );
}
break;
case SUSTAIN:
if ( reg20 & MASK_SUSTAIN ) {
return vol;
}
//In sustain phase, but not sustaining, do regular release
/* FALLTHROUGH */
case RELEASE:
vol += RateForward( releaseAdd );
if ( GCC_UNLIKELY(vol >= ENV_MAX) ) {
volume = ENV_MAX;
SetState( OFF );
return ENV_MAX;
}
break;
}
volume = vol;
return vol;
}
static const VolumeHandler VolumeHandlerTable[5] = {
&Operator::TemplateVolume< Operator::OFF >,
&Operator::TemplateVolume< Operator::RELEASE >,
&Operator::TemplateVolume< Operator::SUSTAIN >,
&Operator::TemplateVolume< Operator::DECAY >,
&Operator::TemplateVolume< Operator::ATTACK >
};
/*INLINE*/ Bitu Operator::ForwardVolume() {
return (Bitu)(currentLevel + (this->*volHandler)());
}
/*INLINE*/ Bitu Operator::ForwardWave() {
waveIndex += waveCurrent;
return waveIndex >> WAVE_SH;
}
void Operator::Write20( const Chip* chip, uint8_t val ) {
uint8_t change = (reg20 ^ val );
if ( !change )
return;
reg20 = val;
//Shift the tremolo bit over the entire register, saved a branch, YES!
tremoloMask = (int8_t)(val) >> 7;
tremoloMask &= ~(( 1 << ENV_EXTRA ) -1);
//Update specific features based on changes
if ( change & MASK_KSR ) {
UpdateRates( chip );
}
//With sustain enable the volume doesn't change
if ( reg20 & MASK_SUSTAIN || ( !releaseAdd ) ) {
rateZero |= ( 1 << SUSTAIN );
} else {
rateZero &= ~( 1 << SUSTAIN );
}
//Frequency multiplier or vibrato changed
if ( change & (0xf | MASK_VIBRATO) ) {
freqMul = chip->freqMul[ val & 0xf ];
UpdateFrequency();
}
}
void Operator::Write40( const Chip* /*chip*/, uint8_t val ) {
if (!(reg40 ^ val ))
return;
reg40 = val;
UpdateAttenuation( );
}
void Operator::Write60( const Chip* chip, uint8_t val ) {
uint8_t change = reg60 ^ val;
reg60 = val;
if ( change & 0x0f ) {
UpdateDecay( chip );
}
if ( change & 0xf0 ) {
UpdateAttack( chip );
}
}
void Operator::Write80( const Chip* chip, uint8_t val ) {
uint8_t change = (reg80 ^ val );
if ( !change )
return;
reg80 = val;
uint8_t sustain = val >> 4;
//Turn 0xf into 0x1f
sustain |= ( sustain + 1) & 0x10;
sustainLevel = sustain << ( ENV_BITS - 5 );
if ( change & 0x0f ) {
UpdateRelease( chip );
}
}
void Operator::WriteE0( const Chip* chip, uint8_t val ) {
if ( !(regE0 ^ val) )
return;
//in opl3 mode you can always select 7 waveforms regardless of waveformselect
const uint8_t waveForm = val & ( ( 0x3 & chip->waveFormMask ) | (0x7 & chip->opl3Active ) );
regE0 = val;
#if ( DBOPL_WAVE == WAVE_HANDLER )
waveHandler = WaveHandlerTable[ waveForm ];
#else
waveBase = WaveTable + WaveBaseTable[ waveForm ];
waveStart = (Bitu)WaveStartTable[ waveForm ] << WAVE_SH;
waveMask = WaveMaskTable[ waveForm ];
#endif
}
/*INLINE*/ void Operator::SetState( uint8_t s ) {
state = s;
volHandler = VolumeHandlerTable[ s ];
}
/*INLINE*/ bool Operator::Silent() const {
if ( !ENV_SILENT( totalLevel + volume ) )
return false;
if ( !(rateZero & ( 1 << state ) ) )
return false;
return true;
}
/*INLINE*/ void Operator::Prepare( const Chip* chip ) {
currentLevel = (uint32_t)(totalLevel + (int32_t)(chip->tremoloValue & tremoloMask));
waveCurrent = waveAdd;
if ( vibStrength >> chip->vibratoShift ) {
int32_t add = (int32_t)(vibrato >> chip->vibratoShift);
//Sign extend over the shift value
int32_t neg = chip->vibratoSign;
//Negate the add with -1 or 0
add = ( add ^ neg ) - neg;
waveCurrent += (Bitu)add;
}
}
void Operator::KeyOn( uint8_t mask ) {
if ( !keyOn ) {
//Restart the frequency generator
#if ( DBOPL_WAVE > WAVE_HANDLER )
waveIndex = waveStart;
#else
waveIndex = 0;
#endif
rateIndex = 0;
SetState( ATTACK );
}
keyOn |= mask;
}
void Operator::KeyOff( uint8_t mask ) {
keyOn &= ~mask;
if ( !keyOn ) {
if ( state != OFF ) {
SetState( RELEASE );
}
}
}
/*INLINE*/ Bits Operator::GetWave( Bitu index, Bitu vol ) {
#if ( DBOPL_WAVE == WAVE_HANDLER )
return waveHandler( index, vol << ( 3 - ENV_EXTRA ) );
#elif ( DBOPL_WAVE == WAVE_TABLEMUL )
return (waveBase[ index & waveMask ] * MulTable[ vol >> ENV_EXTRA ]) >> MUL_SH;
#elif ( DBOPL_WAVE == WAVE_TABLELOG )
int32_t wave = waveBase[ index & waveMask ];
uint32_t total = ( wave & 0x7fff ) + vol << ( 3 - ENV_EXTRA );
int32_t sig = ExpTable[ total & 0xff ];
uint32_t exp = total >> 8;
int32_t neg = wave >> 16;
return ((sig ^ neg) - neg) >> exp;
#else
#error "No valid wave routine"
#endif
}
Bits /*INLINE*/ Operator::GetSample( Bits modulation ) {
Bitu vol = ForwardVolume();
if ( ENV_SILENT( vol ) ) {
//Simply forward the wave
waveIndex += waveCurrent;
return 0;
} else {
Bitu index = ForwardWave();
index += (unsigned long)modulation;
return GetWave( index, vol );
}
}
Operator::Operator() {
chanData = 0;
freqMul = 0;
waveIndex = 0;
waveAdd = 0;
waveCurrent = 0;
keyOn = 0;
ksr = 0;
reg20 = 0;
reg40 = 0;
reg60 = 0;
reg80 = 0;
regE0 = 0;
waveBase = 0;
waveMask = 0;
waveStart = 0;
vibrato = 0;
attackAdd = 0;
decayAdd = 0;
rateIndex = 0;
tremoloMask = 0;
vibStrength = 0;
SetState( OFF );
rateZero = (1 << OFF);
sustainLevel = ENV_MAX;
currentLevel = ENV_MAX;
totalLevel = ENV_MAX;
volume = ENV_MAX;
releaseAdd = 0;
}
/*
Channel
*/
Channel::Channel() {
old[0] = old[1] = 0;
chanData = 0;
regB0 = 0;
regC0 = 0;
maskLeft = -1;
maskRight = -1;
feedback = 31;
fourMask = 0;
synthHandler = &Channel::BlockTemplate< sm2FM >;
}
void Channel::SetChanData( const Chip* chip, uint32_t data ) {
uint32_t change = chanData ^ data;
chanData = data;
Op( 0 )->chanData = data;
Op( 1 )->chanData = data;
//Since a frequency update triggered this, always update frequency
Op( 0 )->UpdateFrequency();
Op( 1 )->UpdateFrequency();
if ( change & ( 0xffu << SHIFT_KSLBASE ) ) {
Op( 0 )->UpdateAttenuation();
Op( 1 )->UpdateAttenuation();
}
if ( change & ( 0xffu << SHIFT_KEYCODE ) ) {
Op( 0 )->UpdateRates( chip );
Op( 1 )->UpdateRates( chip );
}
}
void Channel::UpdateFrequency( const Chip* chip, uint8_t fourOp ) {
//Extrace the frequency bits
uint32_t data = chanData & 0xffff;
uint32_t kslBase = KslTable[ data >> 6 ];
uint32_t keyCode = ( data & 0x1c00) >> 9;
if ( chip->reg08 & 0x40 ) {
keyCode |= ( data & 0x100)>>8; /* notesel == 1 */
} else {
keyCode |= ( data & 0x200)>>9; /* notesel == 0 */
}
//Add the keycode and ksl into the highest bits of chanData
data |= (keyCode << SHIFT_KEYCODE) | ( kslBase << SHIFT_KSLBASE );
( this + 0 )->SetChanData( chip, data );
if ( fourOp & 0x3f ) {
( this + 1 )->SetChanData( chip, data );
}
}
void Channel::WriteA0( const Chip* chip, uint8_t val ) {
uint8_t fourOp = chip->reg104 & chip->opl3Active & fourMask;
//Don't handle writes to silent fourop channels
if ( fourOp > 0x80 )
return;
uint32_t change = (chanData ^ val ) & 0xff;
if ( change ) {
chanData ^= change;
UpdateFrequency( chip, fourOp );
}
}
void Channel::WriteB0( const Chip* chip, uint8_t val ) {
uint8_t fourOp = chip->reg104 & chip->opl3Active & fourMask;
//Don't handle writes to silent fourop channels
if ( fourOp > 0x80 )
return;
Bitu change = (chanData ^ ( (unsigned int)val << 8u ) ) & 0x1f00u;
if ( change ) {
chanData ^= change;
UpdateFrequency( chip, fourOp );
}
//Check for a change in the keyon/off state
if ( !(( val ^ regB0) & 0x20))
return;
regB0 = val;
if ( val & 0x20 ) {
Op(0)->KeyOn( 0x1 );
Op(1)->KeyOn( 0x1 );
if ( fourOp & 0x3f ) {
( this + 1 )->Op(0)->KeyOn( 1 );
( this + 1 )->Op(1)->KeyOn( 1 );
}
} else {
Op(0)->KeyOff( 0x1 );
Op(1)->KeyOff( 0x1 );
if ( fourOp & 0x3f ) {
( this + 1 )->Op(0)->KeyOff( 1 );
( this + 1 )->Op(1)->KeyOff( 1 );
}
}
}
void Channel::WriteC0(const Chip* chip, uint8_t val) {
uint8_t change = val ^ regC0;
if (!change)
return;
regC0 = val;
feedback = (regC0 >> 1) & 7;
if (feedback) {
//We shift the input to the right 10 bit wave index value
feedback = 9 - feedback;
}
else {
feedback = 31;
}
UpdateSynth(chip);
}
void Channel::UpdateSynth( const Chip* chip ) {
//Select the new synth mode
if ( chip->opl3Active ) {
//4-op mode enabled for this channel
if ( (chip->reg104 & fourMask) & 0x3f ) {
Channel* chan0, *chan1;
//Check if it's the 2nd channel in a 4-op
if ( !(fourMask & 0x80 ) ) {
chan0 = this;
chan1 = this + 1;
} else {
chan0 = this - 1;
chan1 = this;
}
uint8_t synth = ( (chan0->regC0 & 1) << 0 )| (( chan1->regC0 & 1) << 1 );
switch ( synth ) {
case 0:
chan0->synthHandler = &Channel::BlockTemplate< sm3FMFM >;
break;
case 1:
chan0->synthHandler = &Channel::BlockTemplate< sm3AMFM >;
break;
case 2:
chan0->synthHandler = &Channel::BlockTemplate< sm3FMAM >;
break;
case 3:
chan0->synthHandler = &Channel::BlockTemplate< sm3AMAM >;
break;
}
//Disable updating percussion channels
} else if ((fourMask & 0x40) && ( chip->regBD & 0x20) ) {
//Regular dual op, am or fm
} else if (regC0 & 1 ) {
synthHandler = &Channel::BlockTemplate< sm3AM >;
} else {
synthHandler = &Channel::BlockTemplate< sm3FM >;
}
maskLeft = (regC0 & 0x10 ) ? -1 : 0;
maskRight = (regC0 & 0x20 ) ? -1 : 0;
//opl2 active
} else {
//Disable updating percussion channels
if ( (fourMask & 0x40) && ( chip->regBD & 0x20 ) ) {
//Regular dual op, am or fm
} else if (regC0 & 1 ) {
synthHandler = &Channel::BlockTemplate< sm2AM >;
} else {
synthHandler = &Channel::BlockTemplate< sm2FM >;
}
}
}
template< bool opl3Mode>
/*INLINE*/ void Channel::GeneratePercussion( Chip* chip, int32_t* output ) {
Channel* chan = this;
//BassDrum
int32_t mod = (int32_t)((uint32_t)(old[0] + old[1]) >> feedback);
old[0] = old[1];
old[1] = (int32_t)Op(0)->GetSample( mod );
//When bassdrum is in AM mode first operator is ignoed
if ( chan->regC0 & 1 ) {
mod = 0;
} else {
mod = old[0];
}
int32_t sample = (int32_t)Op(1)->GetSample( mod );
//Precalculate stuff used by other outputs
uint32_t noiseBit = chip->ForwardNoise() & 0x1;
uint32_t c2 = (uint32_t)Op(2)->ForwardWave();
uint32_t c5 = (uint32_t)Op(5)->ForwardWave();
uint32_t phaseBit = (((c2 & 0x88) ^ ((c2<<5) & 0x80)) | ((c5 ^ (c5<<2)) & 0x20)) ? 0x02 : 0x00;
//Hi-Hat
uint32_t hhVol = (uint32_t)Op(2)->ForwardVolume();
if ( !ENV_SILENT( hhVol ) ) {
uint32_t hhIndex = (phaseBit<<8) | (0x34 << ( phaseBit ^ (noiseBit << 1 )));
sample += (int32_t)Op(2)->GetWave( hhIndex, hhVol );
}
//Snare Drum
uint32_t sdVol = (uint32_t)Op(3)->ForwardVolume();
if ( !ENV_SILENT( sdVol ) ) {
uint32_t sdIndex = ( 0x100 + (c2 & 0x100) ) ^ ( noiseBit << 8 );
sample += (int32_t)Op(3)->GetWave( sdIndex, sdVol );
}
//Tom-tom
sample += (int32_t)Op(4)->GetSample( 0 );
//Top-Cymbal
uint32_t tcVol = (uint32_t)Op(5)->ForwardVolume();
if ( !ENV_SILENT( tcVol ) ) {
uint32_t tcIndex = (1 + phaseBit) << 8;
sample += (int32_t)Op(5)->GetWave( tcIndex, tcVol );
}
sample <<= 1;
if ( opl3Mode ) {
output[0] += sample;
output[1] += sample;
} else {
output[0] += sample;
}
}
template<SynthMode mode>
Channel* Channel::BlockTemplate( Chip* chip, uint32_t samples, int32_t* output ) {
switch( mode ) {
case sm2AM:
case sm3AM:
if ( Op(0)->Silent() && Op(1)->Silent() ) {
old[0] = old[1] = 0;
return (this + 1);
}
break;
case sm2FM:
case sm3FM:
if ( Op(1)->Silent() ) {
old[0] = old[1] = 0;
return (this + 1);
}
break;
case sm3FMFM:
if ( Op(3)->Silent() ) {
old[0] = old[1] = 0;
return (this + 2);
}
break;
case sm3AMFM:
if ( Op(0)->Silent() && Op(3)->Silent() ) {
old[0] = old[1] = 0;
return (this + 2);
}
break;
case sm3FMAM:
if ( Op(1)->Silent() && Op(3)->Silent() ) {
old[0] = old[1] = 0;
return (this + 2);
}
break;
case sm3AMAM:
if ( Op(0)->Silent() && Op(2)->Silent() && Op(3)->Silent() ) {
old[0] = old[1] = 0;
return (this + 2);
}
break;
default:
break;
}
//Init the operators with the current vibrato and tremolo values
Op( 0 )->Prepare( chip );
Op( 1 )->Prepare( chip );
if ( mode > sm4Start ) {
Op( 2 )->Prepare( chip );
Op( 3 )->Prepare( chip );
}
if ( mode > sm6Start ) {
Op( 4 )->Prepare( chip );
Op( 5 )->Prepare( chip );
}
for ( Bitu i = 0; i < samples; i++ ) {
//Early out for percussion handlers
if ( mode == sm2Percussion ) {
GeneratePercussion<false>( chip, output + i );
continue; //Prevent some uninitialized value bitching
} else if ( mode == sm3Percussion ) {
GeneratePercussion<true>( chip, output + i * 2 );
continue; //Prevent some uninitialized value bitching
}
//Do unsigned shift so we can shift out all bits but still stay in 10 bit range otherwise
int32_t mod = (int32_t)((uint32_t)((old[0] + old[1])) >> feedback);
old[0] = old[1];
old[1] = (int32_t)Op(0)->GetSample( mod );
int32_t sample;
int32_t out0 = old[0];
if ( mode == sm2AM || mode == sm3AM ) {
sample = (int32_t)(out0 + Op(1)->GetSample( 0 ));
} else if ( mode == sm2FM || mode == sm3FM ) {
sample = (int32_t)Op(1)->GetSample( out0 );
} else if ( mode == sm3FMFM ) {
Bits next = Op(1)->GetSample( out0 );
next = Op(2)->GetSample( next );
sample = (int32_t)Op(3)->GetSample( next );
} else if ( mode == sm3AMFM ) {
sample = out0;
Bits next = Op(1)->GetSample( 0 );
next = Op(2)->GetSample( next );
sample += (int32_t)Op(3)->GetSample( next );
} else if ( mode == sm3FMAM ) {
sample = (int32_t)Op(1)->GetSample( out0 );
Bits next = Op(2)->GetSample( 0 );
sample += (int32_t)Op(3)->GetSample( next );
} else if ( mode == sm3AMAM ) {
sample = out0;
Bits next = Op(1)->GetSample( 0 );
sample += (int32_t)Op(2)->GetSample( next );
sample += (int32_t)Op(3)->GetSample( 0 );
}
switch( mode ) {
case sm2AM:
case sm2FM:
output[ i ] += sample;
break;
case sm3AM:
case sm3FM:
case sm3FMFM:
case sm3AMFM:
case sm3FMAM:
case sm3AMAM:
output[ i * 2 + 0 ] += sample & maskLeft;
output[ i * 2 + 1 ] += sample & maskRight;
break;
default:
break;
}
}
switch( mode ) {
case sm2AM:
case sm2FM:
case sm3AM:
case sm3FM:
return ( this + 1 );
case sm3FMFM:
case sm3AMFM:
case sm3FMAM:
case sm3AMAM:
return( this + 2 );
case sm2Percussion:
case sm3Percussion:
return( this + 3 );
}
return 0;
}
/*
Chip
*/
Chip::Chip( bool _opl3Mode ) : opl3Mode( _opl3Mode ) {
reg08 = 0;
reg04 = 0;
regBD = 0;
reg104 = 0;
opl3Active = 0;
}
/*INLINE*/ uint32_t Chip::ForwardNoise() {
noiseCounter += noiseAdd;
Bitu count = noiseCounter >> LFO_SH;
noiseCounter &= ((1<<LFO_SH) - 1);
for ( ; count > 0; --count ) {