streamtools/opl.h

   1 /*
   2  *  Copyright (C) 2002-2009  The DOSBox Team
   3  *  OPL2/OPL3 emulation library
   4  *
   5  *  This library is free software; you can redistribute it and/or
   6  *  modify it under the terms of the GNU Lesser General Public
   7  *  License as published by the Free Software Foundation; either
   8  *  version 2.1 of the License, or (at your option) any later version.
   9  *
  10  *  This library is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *  Lesser General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU Lesser General Public
  16  *  License along with this library; if not, write to the Free Software
  17  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20
  21 /*
  22  * Originally based on ADLIBEMU.C, an AdLib/OPL2 emulation library by Ken Silverman
  23  * Copyright (C) 1998-2001 Ken Silverman
  24  * Ken Silverman's official web site: "http://www.advsys.net/ken"
  25  */
  26
  27 #ifdef OPL_CPP
  28 #define EXTERN
  29 #else
  30 #define EXTERN extern
  31 #endif
  32
  33
  34 #define fltype double
  35
  36 /*
  37         define Bits, Bitu, Bit32s, Bit32u, Bit16s, Bit16u, Bit8s, Bit8u here
  38 */
  39
  40 #include <stdint.h>
  41 typedef uintptr_t       Bitu;
  42 typedef intptr_t        Bits;
  43 typedef uint32_t        Bit32u;
  44 typedef int32_t         Bit32s;
  45 typedef uint16_t        Bit16u;
  46 typedef int16_t         Bit16s;
  47 typedef uint8_t         Bit8u;
  48 typedef int8_t          Bit8s;
  49
  50
  51
  52 /*
  53         define attribution that inlines/forces inlining of a function (optional)
  54 */
  55 #define OPL_INLINE INLINE
  56
  57
  58 #undef NUM_CHANNELS
  59 #if defined(OPLTYPE_IS_OPL3)
  60 #define NUM_CHANNELS    18
  61 #else
  62 #define NUM_CHANNELS    9
  63 #endif
  64
  65 #define MAXOPERATORS    (NUM_CHANNELS*2)
  66
  67
  68 #define FL05    ((fltype)0.5)
  69 #define FL2             ((fltype)2.0)
  70 #define PI              ((fltype)3.1415926535897932384626433832795)
  71
  72
  73 #define FIXEDPT                 0x10000         // fixed-point calculations using 16+16
  74 #define FIXEDPT_LFO             0x1000000       // fixed-point calculations using 8+24
  75
  76 #define WAVEPREC                1024            // waveform precision (10 bits)
  77
  78 #define INTFREQU                ((fltype)(14318180.0 / 288.0))          // clocking of the chip
  79
  80
  81 #define OF_TYPE_ATT                     0
  82 #define OF_TYPE_DEC                     1
  83 #define OF_TYPE_REL                     2
  84 #define OF_TYPE_SUS                     3
  85 #define OF_TYPE_SUS_NOKEEP      4
  86 #define OF_TYPE_OFF                     5
  87
  88 #define ARC_CONTROL                     0x00
  89 #define ARC_TVS_KSR_MUL         0x20
  90 #define ARC_KSL_OUTLEV          0x40
  91 #define ARC_ATTR_DECR           0x60
  92 #define ARC_SUSL_RELR           0x80
  93 #define ARC_FREQ_NUM            0xa0
  94 #define ARC_KON_BNUM            0xb0
  95 #define ARC_PERC_MODE           0xbd
  96 #define ARC_FEEDBACK            0xc0
  97 #define ARC_WAVE_SEL            0xe0
  98
  99 #define ARC_SECONDSET           0x100   // second operator set for OPL3
 100
 101
 102 #define OP_ACT_OFF                      0x00
 103 #define OP_ACT_NORMAL           0x01    // regular channel activated (bitmasked)
 104 #define OP_ACT_PERC                     0x02    // percussion channel activated (bitmasked)
 105
 106 #define BLOCKBUF_SIZE           512
 107
 108
 109 // vibrato constants
 110 #define VIBTAB_SIZE                     8
 111 #define VIBFAC                          70/50000                // no braces, integer mul/div
 112
 113 // tremolo constants and table
 114 #define TREMTAB_SIZE            53
 115 #define TREM_FREQ                       ((fltype)(3.7))                 // tremolo at 3.7hz
 116
 117
 118 /* operator struct definition
 119      For OPL2 all 9 channels consist of two operators each, carrier and modulator.
 120      Channel x has operators x as modulator and operators (9+x) as carrier.
 121      For OPL3 all 18 channels consist either of two operators (2op mode) or four
 122      operators (4op mode) which is determined through register4 of the second
 123      adlib register set.
 124      Only the channels 0,1,2 (first set) and 9,10,11 (second set) can act as
 125      4op channels. The two additional operators for a channel y come from the
 126      2op channel y+3 so the operatorss y, (9+y), y+3, (9+y)+3 make up a 4op
 127      channel.
 128 */
 129 typedef struct operator_struct {
 130         Bit32s cval, lastcval;                  // current output/last output (used for feedback)
 131         Bit32u tcount, wfpos, tinc;             // time (position in waveform) and time increment
 132         fltype amp, step_amp;                   // and amplification (envelope)
 133         fltype vol;                                             // volume
 134         fltype sustain_level;                   // sustain level
 135         Bit32s mfbi;                                    // feedback amount
 136         fltype a0, a1, a2, a3;                  // attack rate function coefficients
 137         fltype decaymul, releasemul;    // decay/release rate functions
 138         Bit32u op_state;                                // current state of operator (attack/decay/sustain/release/off)
 139         Bit32u toff;
 140         Bit32s freq_high;                               // highest three bits of the frequency, used for vibrato calculations
 141         Bit16s* cur_wform;                              // start of selected waveform
 142         Bit32u cur_wmask;                               // mask for selected waveform
 143         Bit32u act_state;                               // activity state (regular, percussion)
 144         bool sus_keep;                                  // keep sustain level when decay finished
 145         bool vibrato,tremolo;                   // vibrato/tremolo enable bits
 146
 147         // variables used to provide non-continuous envelopes
 148         Bit32u generator_pos;                   // for non-standard sample rates we need to determine how many samples have passed
 149         Bits cur_env_step;                              // current (standardized) sample position
 150         Bits env_step_a,env_step_d,env_step_r;  // number of std samples of one step (for attack/decay/release mode)
 151         Bit8u step_skip_pos_a;                  // position of 8-cyclic step skipping (always 2^x to check against mask)
 152         Bits env_step_skip_a;                   // bitmask that determines if a step is skipped (respective bit is zero then)
 153
 154 #if defined(OPLTYPE_IS_OPL3)
 155         bool is_4op,is_4op_attached;    // base of a 4op channel/part of a 4op channel
 156         Bit32s left_pan,right_pan;              // opl3 stereo panning amount
 157 #endif
 158 } op_type;
 159
 160 // per-chip variables
 161 EXTERN Bitu chip_num;
 162 EXTERN op_type op[MAXOPERATORS];
 163
 164 EXTERN Bits int_samplerate;
 165
 166 EXTERN Bit8u status;
 167 EXTERN Bit32u opl_index;
 168 #if defined(OPLTYPE_IS_OPL3)
 169 EXTERN Bit8u adlibreg[512];     // adlib register set (including second set)
 170 EXTERN Bit8u wave_sel[44];              // waveform selection
 171 #else
 172 EXTERN Bit8u adlibreg[256];     // adlib register set
 173 EXTERN Bit8u wave_sel[22];              // waveform selection
 174 #endif
 175
 176
 177 // vibrato/tremolo increment/counter
 178 EXTERN Bit32u vibtab_pos;
 179 EXTERN Bit32u vibtab_add;
 180 EXTERN Bit32u tremtab_pos;
 181 EXTERN Bit32u tremtab_add;
 182
 183
 184 // enable an operator
 185 void enable_operator(Bitu regbase, op_type* op_pt);
 186
 187 // functions to change parameters of an operator
 188 void change_frequency(Bitu chanbase, Bitu regbase, op_type* op_pt);
 189
 190 void change_attackrate(Bitu regbase, op_type* op_pt);
 191 void change_decayrate(Bitu regbase, op_type* op_pt);
 192 void change_releaserate(Bitu regbase, op_type* op_pt);
 193 void change_sustainlevel(Bitu regbase, op_type* op_pt);
 194 void change_waveform(Bitu regbase, op_type* op_pt);
 195 void change_keepsustain(Bitu regbase, op_type* op_pt);
 196 void change_vibrato(Bitu regbase, op_type* op_pt);
 197 void change_feedback(Bitu chanbase, op_type* op_pt);
 198
 199 // general functions
 200 void adlib_init(Bit32u samplerate);
 201 void adlib_write(Bitu idx, Bit8u val);
 202 void adlib_getsample(Bit16s* sndptr, Bits numsamples);
 203
 204 Bitu adlib_reg_read(Bitu port);
 205 void adlib_write_index(Bitu port, Bit8u val);
 206
 207 #ifdef OPL_CPP
 208 static Bit32u generator_add;    // should be a chip parameter
 209 #endif