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/*
* Copyright (C) 2002-2010 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <inttypes.h>
//Use 8 handlers based on a small logatirmic wavetabe and an exponential table for volume
#define WAVE_HANDLER 10
//Use a logarithmic wavetable with an exponential table for volume
#define WAVE_TABLELOG 11
//Use a linear wavetable with a multiply table for volume
#define WAVE_TABLEMUL 12
//Select the type of wave generator routine
#define DBOPL_WAVE WAVE_TABLEMUL
typedef struct _Chip Chip;
typedef struct _Operator Operator;
typedef struct _Channel Channel;
typedef uintptr_t Bitu;
typedef intptr_t Bits;
typedef uint32_t Bit32u;
typedef int32_t Bit32s;
typedef uint16_t Bit16u;
typedef int16_t Bit16s;
typedef uint8_t Bit8u;
typedef int8_t Bit8s;
#if (DBOPL_WAVE == WAVE_HANDLER)
typedef Bits ( DB_FASTCALL *WaveHandler) ( Bitu i, Bitu volume );
#endif
#define DB_FASTCALL
typedef Bits (*VolumeHandler)(Operator *self);
typedef Channel* (*SynthHandler)(Channel *self, Chip* chip, Bit32u samples, Bit32s* output );
//Different synth modes that can generate blocks of data
typedef enum {
sm2AM,
sm2FM,
sm3AM,
sm3FM,
sm4Start,
sm3FMFM,
sm3AMFM,
sm3FMAM,
sm3AMAM,
sm6Start,
sm2Percussion,
sm3Percussion,
} SynthMode;
//Shifts for the values contained in chandata variable
enum {
SHIFT_KSLBASE = 16,
SHIFT_KEYCODE = 24,
};
//Masks for operator 20 values
enum {
MASK_KSR = 0x10,
MASK_SUSTAIN = 0x20,
MASK_VIBRATO = 0x40,
MASK_TREMOLO = 0x80,
};
typedef enum {
OFF,
RELEASE,
SUSTAIN,
DECAY,
ATTACK,
} OperatorState;
struct _Operator {
VolumeHandler volHandler;
#if (DBOPL_WAVE == WAVE_HANDLER)
WaveHandler waveHandler; //Routine that generate a wave
#else
Bit16s* waveBase;
Bit32u waveMask;
Bit32u waveStart;
#endif
Bit32u waveIndex; //WAVE_BITS shifted counter of the frequency index
Bit32u waveAdd; //The base frequency without vibrato
Bit32u waveCurrent; //waveAdd + vibratao
Bit32u chanData; //Frequency/octave and derived data coming from whatever channel controls this
Bit32u freqMul; //Scale channel frequency with this, TODO maybe remove?
Bit32u vibrato; //Scaled up vibrato strength
Bit32s sustainLevel; //When stopping at sustain level stop here
Bit32s totalLevel; //totalLevel is added to every generated volume
Bit32u currentLevel; //totalLevel + tremolo
Bit32s volume; //The currently active volume
Bit32u attackAdd; //Timers for the different states of the envelope
Bit32u decayAdd;
Bit32u releaseAdd;
Bit32u rateIndex; //Current position of the evenlope
Bit8u rateZero; //Bits for the different states of the envelope having no changes
Bit8u keyOn; //Bitmask of different values that can generate keyon
//Registers, also used to check for changes
Bit8u reg20, reg40, reg60, reg80, regE0;
//Active part of the envelope we're in
Bit8u state;
//0xff when tremolo is enabled
Bit8u tremoloMask;
//Strength of the vibrato
Bit8u vibStrength;
//Keep track of the calculated KSR so we can check for changes
Bit8u ksr;
};
struct _Channel {
Operator op[2];
SynthHandler synthHandler;
Bit32u chanData; //Frequency/octave and derived values
Bit32s old[2]; //Old data for feedback
Bit8u feedback; //Feedback shift
Bit8u regB0; //Register values to check for changes
Bit8u regC0;
//This should correspond with reg104, bit 6 indicates a Percussion channel, bit 7 indicates a silent channel
Bit8u fourMask;
Bit8s maskLeft; //Sign extended values for both channel's panning
Bit8s maskRight;
};
struct _Chip {
//This is used as the base counter for vibrato and tremolo
Bit32u lfoCounter;
Bit32u lfoAdd;
Bit32u noiseCounter;
Bit32u noiseAdd;
Bit32u noiseValue;
//Frequency scales for the different multiplications
Bit32u freqMul[16];
//Rates for decay and release for rate of this chip
Bit32u linearRates[76];
//Best match attack rates for the rate of this chip
Bit32u attackRates[76];
//18 channels with 2 operators each
Channel chan[18];
Bit8u reg104;
Bit8u reg08;
Bit8u reg04;
Bit8u regBD;
Bit8u vibratoIndex;
Bit8u tremoloIndex;
Bit8s vibratoSign;
Bit8u vibratoShift;
Bit8u tremoloValue;
Bit8u vibratoStrength;
Bit8u tremoloStrength;
//Mask for allowed wave forms
Bit8u waveFormMask;
//0 or -1 when enabled
Bit8s opl3Active;
};
/*
struct Handler : public Adlib::Handler {
DBOPL::Chip chip;
virtual Bit32u WriteAddr( Bit32u port, Bit8u val );
virtual void WriteReg( Bit32u addr, Bit8u val );
virtual void Generate( MixerChannel* chan, Bitu samples );
virtual void Init( Bitu rate );
};
*/
void Chip__Setup(Chip *self, Bit32u rate );
void DBOPL_InitTables( void );
void Chip__Chip(Chip *self);
void Chip__WriteReg(Chip *self, Bit32u reg, Bit8u val );
void Chip__GenerateBlock2(Chip *self, Bitu total, Bit32s* output );
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