/*
 *  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" //NSM
#include <sys/types.h>
#include <stdint.h>

#ifdef _MSC_VER
  #if _MSC_VER < 1300
    #include <BaseTsd.h>
    typedef INT_PTR   intptr_t;
  #endif
#endif

//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 );
};
*/

#ifdef __cplusplus
extern "C" void Chip__Setup(Chip *self, Bit32u rate );
extern "C" void DBOPL_InitTables( void );
extern "C" void Chip__Chip(Chip *self);
extern "C" void Chip__WriteReg(Chip *self, Bit32u reg, Bit8u val );
extern "C" void Chip__GenerateBlock2(Chip *self, Bitu total, Bit32s* output );
#else
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 );

#endif

