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furnace/extern/opn/ym3438.c

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Nuked-OPN2 + ymfm combo option for all OPN chips modified Nuked doing FM and ymfm doing SSG/ADPCM
2022-12-24 07:29:37 +00:00
/*
* Copyright (C) 2017-2022 Alexey Khokholov (Nuke.YKT)
*
* This file is part of Nuked OPN2.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Nuked OPN2(Yamaha YM3438) emulator.
* Thanks:
* Silicon Pr0n:
* Yamaha YM3438 decap and die shot(digshadow).
* OPLx decapsulated(Matthew Gambrell, Olli Niemitalo):
* OPL2 ROMs.
*
* version: 1.0.11
*/
#include <string.h>
#include "ym3438.h"
#define SIGN_EXTEND(bit_index, value) (((value) & ((1u << (bit_index)) - 1u)) - ((value) & (1u << (bit_index))))
enum {
eg_num_attack = 0,
eg_num_decay = 1,
eg_num_sustain = 2,
eg_num_release = 3
};
/* logsin table */
static const Bit16u logsinrom[256] = {
0x859, 0x6c3, 0x607, 0x58b, 0x52e, 0x4e4, 0x4a6, 0x471,
0x443, 0x41a, 0x3f5, 0x3d3, 0x3b5, 0x398, 0x37e, 0x365,
0x34e, 0x339, 0x324, 0x311, 0x2ff, 0x2ed, 0x2dc, 0x2cd,
0x2bd, 0x2af, 0x2a0, 0x293, 0x286, 0x279, 0x26d, 0x261,
0x256, 0x24b, 0x240, 0x236, 0x22c, 0x222, 0x218, 0x20f,
0x206, 0x1fd, 0x1f5, 0x1ec, 0x1e4, 0x1dc, 0x1d4, 0x1cd,
0x1c5, 0x1be, 0x1b7, 0x1b0, 0x1a9, 0x1a2, 0x19b, 0x195,
0x18f, 0x188, 0x182, 0x17c, 0x177, 0x171, 0x16b, 0x166,
0x160, 0x15b, 0x155, 0x150, 0x14b, 0x146, 0x141, 0x13c,
0x137, 0x133, 0x12e, 0x129, 0x125, 0x121, 0x11c, 0x118,
0x114, 0x10f, 0x10b, 0x107, 0x103, 0x0ff, 0x0fb, 0x0f8,
0x0f4, 0x0f0, 0x0ec, 0x0e9, 0x0e5, 0x0e2, 0x0de, 0x0db,
0x0d7, 0x0d4, 0x0d1, 0x0cd, 0x0ca, 0x0c7, 0x0c4, 0x0c1,
0x0be, 0x0bb, 0x0b8, 0x0b5, 0x0b2, 0x0af, 0x0ac, 0x0a9,
0x0a7, 0x0a4, 0x0a1, 0x09f, 0x09c, 0x099, 0x097, 0x094,
0x092, 0x08f, 0x08d, 0x08a, 0x088, 0x086, 0x083, 0x081,
0x07f, 0x07d, 0x07a, 0x078, 0x076, 0x074, 0x072, 0x070,
0x06e, 0x06c, 0x06a, 0x068, 0x066, 0x064, 0x062, 0x060,
0x05e, 0x05c, 0x05b, 0x059, 0x057, 0x055, 0x053, 0x052,
0x050, 0x04e, 0x04d, 0x04b, 0x04a, 0x048, 0x046, 0x045,
0x043, 0x042, 0x040, 0x03f, 0x03e, 0x03c, 0x03b, 0x039,
0x038, 0x037, 0x035, 0x034, 0x033, 0x031, 0x030, 0x02f,
0x02e, 0x02d, 0x02b, 0x02a, 0x029, 0x028, 0x027, 0x026,
0x025, 0x024, 0x023, 0x022, 0x021, 0x020, 0x01f, 0x01e,
0x01d, 0x01c, 0x01b, 0x01a, 0x019, 0x018, 0x017, 0x017,
0x016, 0x015, 0x014, 0x014, 0x013, 0x012, 0x011, 0x011,
0x010, 0x00f, 0x00f, 0x00e, 0x00d, 0x00d, 0x00c, 0x00c,
0x00b, 0x00a, 0x00a, 0x009, 0x009, 0x008, 0x008, 0x007,
0x007, 0x007, 0x006, 0x006, 0x005, 0x005, 0x005, 0x004,
0x004, 0x004, 0x003, 0x003, 0x003, 0x002, 0x002, 0x002,
0x002, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001, 0x001,
0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000, 0x000
};
/* exp table */
static const Bit16u exprom[256] = {
0x000, 0x003, 0x006, 0x008, 0x00b, 0x00e, 0x011, 0x014,
0x016, 0x019, 0x01c, 0x01f, 0x022, 0x025, 0x028, 0x02a,
0x02d, 0x030, 0x033, 0x036, 0x039, 0x03c, 0x03f, 0x042,
0x045, 0x048, 0x04b, 0x04e, 0x051, 0x054, 0x057, 0x05a,
0x05d, 0x060, 0x063, 0x066, 0x069, 0x06c, 0x06f, 0x072,
0x075, 0x078, 0x07b, 0x07e, 0x082, 0x085, 0x088, 0x08b,
0x08e, 0x091, 0x094, 0x098, 0x09b, 0x09e, 0x0a1, 0x0a4,
0x0a8, 0x0ab, 0x0ae, 0x0b1, 0x0b5, 0x0b8, 0x0bb, 0x0be,
0x0c2, 0x0c5, 0x0c8, 0x0cc, 0x0cf, 0x0d2, 0x0d6, 0x0d9,
0x0dc, 0x0e0, 0x0e3, 0x0e7, 0x0ea, 0x0ed, 0x0f1, 0x0f4,
0x0f8, 0x0fb, 0x0ff, 0x102, 0x106, 0x109, 0x10c, 0x110,
0x114, 0x117, 0x11b, 0x11e, 0x122, 0x125, 0x129, 0x12c,
0x130, 0x134, 0x137, 0x13b, 0x13e, 0x142, 0x146, 0x149,
0x14d, 0x151, 0x154, 0x158, 0x15c, 0x160, 0x163, 0x167,
0x16b, 0x16f, 0x172, 0x176, 0x17a, 0x17e, 0x181, 0x185,
0x189, 0x18d, 0x191, 0x195, 0x199, 0x19c, 0x1a0, 0x1a4,
0x1a8, 0x1ac, 0x1b0, 0x1b4, 0x1b8, 0x1bc, 0x1c0, 0x1c4,
0x1c8, 0x1cc, 0x1d0, 0x1d4, 0x1d8, 0x1dc, 0x1e0, 0x1e4,
0x1e8, 0x1ec, 0x1f0, 0x1f5, 0x1f9, 0x1fd, 0x201, 0x205,
0x209, 0x20e, 0x212, 0x216, 0x21a, 0x21e, 0x223, 0x227,
0x22b, 0x230, 0x234, 0x238, 0x23c, 0x241, 0x245, 0x249,
0x24e, 0x252, 0x257, 0x25b, 0x25f, 0x264, 0x268, 0x26d,
0x271, 0x276, 0x27a, 0x27f, 0x283, 0x288, 0x28c, 0x291,
0x295, 0x29a, 0x29e, 0x2a3, 0x2a8, 0x2ac, 0x2b1, 0x2b5,
0x2ba, 0x2bf, 0x2c4, 0x2c8, 0x2cd, 0x2d2, 0x2d6, 0x2db,
0x2e0, 0x2e5, 0x2e9, 0x2ee, 0x2f3, 0x2f8, 0x2fd, 0x302,
0x306, 0x30b, 0x310, 0x315, 0x31a, 0x31f, 0x324, 0x329,
0x32e, 0x333, 0x338, 0x33d, 0x342, 0x347, 0x34c, 0x351,
0x356, 0x35b, 0x360, 0x365, 0x36a, 0x370, 0x375, 0x37a,
0x37f, 0x384, 0x38a, 0x38f, 0x394, 0x399, 0x39f, 0x3a4,
0x3a9, 0x3ae, 0x3b4, 0x3b9, 0x3bf, 0x3c4, 0x3c9, 0x3cf,
0x3d4, 0x3da, 0x3df, 0x3e4, 0x3ea, 0x3ef, 0x3f5, 0x3fa
};
/* Note table */
static const Bit32u fn_note[16] = {
0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 3, 3, 3, 3, 3, 3
};
/* Envelope generator */
static const Bit32u eg_stephi[4][4] = {
{ 0, 0, 0, 0 },
{ 1, 0, 0, 0 },
{ 1, 0, 1, 0 },
{ 1, 1, 1, 0 }
};
static const Bit8u eg_am_shift[4] = {
7, 3, 1, 0
};
/* Phase generator */
static const Bit32u pg_detune[8] = { 16, 17, 19, 20, 22, 24, 27, 29 };
static const Bit32u pg_lfo_sh1[8][8] = {
{ 7, 7, 7, 7, 7, 7, 7, 7 },
{ 7, 7, 7, 7, 7, 7, 7, 7 },
{ 7, 7, 7, 7, 7, 7, 1, 1 },
{ 7, 7, 7, 7, 1, 1, 1, 1 },
{ 7, 7, 7, 1, 1, 1, 1, 0 },
{ 7, 7, 1, 1, 0, 0, 0, 0 },
{ 7, 7, 1, 1, 0, 0, 0, 0 },
{ 7, 7, 1, 1, 0, 0, 0, 0 }
};
static const Bit32u pg_lfo_sh2[8][8] = {
{ 7, 7, 7, 7, 7, 7, 7, 7 },
{ 7, 7, 7, 7, 2, 2, 2, 2 },
{ 7, 7, 7, 2, 2, 2, 7, 7 },
{ 7, 7, 2, 2, 7, 7, 2, 2 },
{ 7, 7, 2, 7, 7, 7, 2, 7 },
{ 7, 7, 7, 2, 7, 7, 2, 1 },
{ 7, 7, 7, 2, 7, 7, 2, 1 },
{ 7, 7, 7, 2, 7, 7, 2, 1 }
};
/* Address decoder */
static const Bit32u op_offset[12] = {
0x000, /* Ch1 OP1/OP2 */
0x001, /* Ch2 OP1/OP2 */
0x002, /* Ch3 OP1/OP2 */
0x100, /* Ch4 OP1/OP2 */
0x101, /* Ch5 OP1/OP2 */
0x102, /* Ch6 OP1/OP2 */
0x004, /* Ch1 OP3/OP4 */
0x005, /* Ch2 OP3/OP4 */
0x006, /* Ch3 OP3/OP4 */
0x104, /* Ch4 OP3/OP4 */
0x105, /* Ch5 OP3/OP4 */
0x106 /* Ch6 OP3/OP4 */
};
static const Bit32u ch_offset[6] = {
0x000, /* Ch1 */
0x001, /* Ch2 */
0x002, /* Ch3 */
0x100, /* Ch4 */
0x101, /* Ch5 */
0x102 /* Ch6 */
};
/* LFO */
static const Bit32u lfo_cycles[8] = {
108, 77, 71, 67, 62, 44, 8, 5
};
/* FM algorithm */
static const Bit32u fm_algorithm[4][6][8] = {
{
{ 1, 1, 1, 1, 1, 1, 1, 1 }, /* OP1_0 */
{ 1, 1, 1, 1, 1, 1, 1, 1 }, /* OP1_1 */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* OP2 */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* Last operator */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* Last operator */
{ 0, 0, 0, 0, 0, 0, 0, 1 } /* Out */
},
{
{ 0, 1, 0, 0, 0, 1, 0, 0 }, /* OP1_0 */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* OP1_1 */
{ 1, 1, 1, 0, 0, 0, 0, 0 }, /* OP2 */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* Last operator */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* Last operator */
{ 0, 0, 0, 0, 0, 1, 1, 1 } /* Out */
},
{
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* OP1_0 */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* OP1_1 */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* OP2 */
{ 1, 0, 0, 1, 1, 1, 1, 0 }, /* Last operator */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* Last operator */
{ 0, 0, 0, 0, 1, 1, 1, 1 } /* Out */
},
{
{ 0, 0, 1, 0, 0, 1, 0, 0 }, /* OP1_0 */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* OP1_1 */
{ 0, 0, 0, 1, 0, 0, 0, 0 }, /* OP2 */
{ 1, 1, 0, 1, 1, 0, 0, 0 }, /* Last operator */
{ 0, 0, 1, 0, 0, 0, 0, 0 }, /* Last operator */
{ 1, 1, 1, 1, 1, 1, 1, 1 } /* Out */
}
};
static void OPN2_DoIO(ym3438_t *chip)
{
/* Write signal check */
chip->write_a_en = (chip->write_a & 0x03) == 0x01;
chip->write_d_en = (chip->write_d & 0x03) == 0x01;
chip->write_a <<= 1;
chip->write_d <<= 1;
/* Busy counter */
chip->busy = chip->write_busy;
chip->write_busy_cnt += chip->write_busy;
chip->write_busy = (chip->write_busy && !(chip->write_busy_cnt >> 5)) || chip->write_d_en;
chip->write_busy_cnt &= 0x1f;
}
static void OPN2_DoRegWrite(ym3438_t *chip)
{
Bit32u i;
Bit32u slot = chip->cycles % 12;
Bit32u address;
Bit32u channel = chip->channel;
/* Update registers */
if (chip->write_fm_data)
{
/* Slot */
if (op_offset[slot] == (chip->address & 0x107))
{
if (chip->address & 0x08)
{
/* OP2, OP4 */
slot += 12;
}
address = chip->address & 0xf0;
switch (address)
{
case 0x30: /* DT, MULTI */
chip->multi[slot] = chip->data & 0x0f;
if (!chip->multi[slot])
{
chip->multi[slot] = 1;
}
else
{
chip->multi[slot] <<= 1;
}
chip->dt[slot] = (chip->data >> 4) & 0x07;
break;
case 0x40: /* TL */
chip->tl[slot] = chip->data & 0x7f;
break;
case 0x50: /* KS, AR */
chip->ar[slot] = chip->data & 0x1f;
chip->ks[slot] = (chip->data >> 6) & 0x03;
break;
case 0x60: /* AM, DR */
chip->dr[slot] = chip->data & 0x1f;
chip->am[slot] = (chip->data >> 7) & 0x01;
break;
case 0x70: /* SR */
chip->sr[slot] = chip->data & 0x1f;
break;
case 0x80: /* SL, RR */
chip->rr[slot] = chip->data & 0x0f;
chip->sl[slot] = (chip->data >> 4) & 0x0f;
chip->sl[slot] |= (chip->sl[slot] + 1) & 0x10;
break;
case 0x90: /* SSG-EG */
chip->ssg_eg[slot] = chip->data & 0x0f;
break;
default:
break;
}
}
/* Channel */
if (ch_offset[channel] == (chip->address & 0x103))
{
address = chip->address & 0xfc;
switch (address)
{
case 0xa0:
chip->fnum[channel] = (chip->data & 0xff) | ((chip->reg_a4 & 0x07) << 8);
chip->block[channel] = (chip->reg_a4 >> 3) & 0x07;
chip->kcode[channel] = (chip->block[channel] << 2) | fn_note[chip->fnum[channel] >> 7];
break;
case 0xa4:
chip->reg_a4 = chip->data & 0xff;
break;
case 0xa8:
chip->fnum_3ch[channel] = (chip->data & 0xff) | ((chip->reg_ac & 0x07) << 8);
chip->block_3ch[channel] = (chip->reg_ac >> 3) & 0x07;
chip->kcode_3ch[channel] = (chip->block_3ch[channel] << 2) | fn_note[chip->fnum_3ch[channel] >> 7];
break;
case 0xac:
chip->reg_ac = chip->data & 0xff;
break;
case 0xb0:
chip->connect[channel] = chip->data & 0x07;
chip->fb[channel] = (chip->data >> 3) & 0x07;
break;
case 0xb4:
chip->pms[channel] = chip->data & 0x07;
chip->ams[channel] = (chip->data >> 4) & 0x03;
chip->pan_l[channel] = (chip->data >> 7) & 0x01;
chip->pan_r[channel] = (chip->data >> 6) & 0x01;
break;
default:
break;
}
}
}
if (chip->write_a_en || chip->write_d_en)
{
/* Data */
if (chip->write_a_en)
{
chip->write_fm_data = 0;
}
if (chip->write_fm_address && chip->write_d_en)
{
chip->write_fm_data = 1;
}
/* Address */
if (chip->write_a_en)
{
if ((chip->write_data & 0xf0) != 0x00)
{
/* FM Write */
chip->address = chip->write_data;
chip->write_fm_address = 1;
}
else
{
/* SSG write */
chip->write_fm_address = 0;
}
}
/* FM Mode */
/* Data */
if (chip->write_d_en && (chip->write_data & 0x100) == 0)
{
switch (chip->write_fm_mode_a)
{
case 0x21: /* LSI test 1 */
for (i = 0; i < 8; i++)
{
chip->mode_test_21[i] = (chip->write_data >> i) & 0x01;
}
break;
case 0x22: /* LFO control */
if ((chip->write_data >> 3) & 0x01)
{
chip->lfo_en = 0x7f;
}
else
{
chip->lfo_en = 0;
}
chip->lfo_freq = chip->write_data & 0x07;
break;
case 0x24: /* Timer A */
chip->timer_a_reg &= 0x03;
chip->timer_a_reg |= (chip->write_data & 0xff) << 2;
break;
case 0x25:
chip->timer_a_reg &= 0x3fc;
chip->timer_a_reg |= chip->write_data & 0x03;
break;
case 0x26: /* Timer B */
chip->timer_b_reg = chip->write_data & 0xff;
break;
case 0x27: /* CSM, Timer control */
chip->mode_ch3 = (chip->write_data & 0xc0) >> 6;
chip->mode_csm = chip->mode_ch3 == 2;
chip->timer_a_load = chip->write_data & 0x01;
chip->timer_a_enable = (chip->write_data >> 2) & 0x01;
chip->timer_a_reset = (chip->write_data >> 4) & 0x01;
chip->timer_b_load = (chip->write_data >> 1) & 0x01;
chip->timer_b_enable = (chip->write_data >> 3) & 0x01;
chip->timer_b_reset = (chip->write_data >> 5) & 0x01;
break;
case 0x28: /* Key on/off */
for (i = 0; i < 4; i++)
{
chip->mode_kon_operator[i] = (chip->write_data >> (4 + i)) & 0x01;
}
if ((chip->write_data & 0x03) == 0x03)
{
/* Invalid address */
chip->mode_kon_channel = 0xff;
}
else
{
chip->mode_kon_channel = (chip->write_data & 0x03) + ((chip->write_data >> 2) & 1) * 3;
}
break;
case 0x2a: /* DAC data */
chip->dacdata &= 0x01;
chip->dacdata |= (chip->write_data ^ 0x80) << 1;
break;
case 0x2b: /* DAC enable */
chip->dacen = chip->write_data >> 7;
break;
case 0x2c: /* LSI test 2 */
for (i = 0; i < 8; i++)
{
chip->mode_test_2c[i] = (chip->write_data >> i) & 0x01;
}
chip->dacdata &= 0x1fe;
chip->dacdata |= chip->mode_test_2c[3];
chip->eg_custom_timer = !chip->mode_test_2c[7] && chip->mode_test_2c[6];
break;
default:
break;
}
}
/* Address */
if (chip->write_a_en)
{
chip->write_fm_mode_a = chip->write_data & 0x1ff;
}
}
if (chip->write_fm_data)
{
chip->data = chip->write_data & 0xff;
}
}
static void OPN2_PhaseCalcIncrement(ym3438_t *chip)
{
Bit32u chan = chip->channel;
Bit32u slot = chip->cycles;
Bit32u fnum = chip->pg_fnum;
Bit32u fnum_h = fnum >> 4;
Bit32u fm;
Bit32u basefreq;
Bit8u lfo = chip->lfo_pm;
Bit8u lfo_l = lfo & 0x0f;
Bit8u pms = chip->pms[chan];
Bit8u dt = chip->dt[slot];
Bit8u dt_l = dt & 0x03;
Bit8u detune = 0;
Bit8u block, note;
Bit8u sum, sum_h, sum_l;
Bit8u kcode = chip->pg_kcode;
fnum <<= 1;
/* Apply LFO */
if (lfo_l & 0x08)
{
lfo_l ^= 0x0f;
}
fm = (fnum_h >> pg_lfo_sh1[pms][lfo_l]) + (fnum_h >> pg_lfo_sh2[pms][lfo_l]);
if (pms > 5)
{
fm <<= pms - 5;
}
fm >>= 2;
if (lfo & 0x10)
{
fnum -= fm;
}
else
{
fnum += fm;
}
fnum &= 0xfff;
basefreq = (fnum << chip->pg_block) >> 2;
/* Apply detune */
if (dt_l)
{
if (kcode > 0x1c)
{
kcode = 0x1c;
}
block = kcode >> 2;
note = kcode & 0x03;
sum = block + 9 + ((dt_l == 3) | (dt_l & 0x02));
sum_h = sum >> 1;
sum_l = sum & 0x01;
detune = pg_detune[(sum_l << 2) | note] >> (9 - sum_h);
}
if (dt & 0x04)
{
basefreq -= detune;
}
else
{
basefreq += detune;
}
basefreq &= 0x1ffff;
chip->pg_inc[slot] = (basefreq * chip->multi[slot]) >> 1;
chip->pg_inc[slot] &= 0xfffff;
}
static void OPN2_PhaseGenerate(ym3438_t *chip)
{
Bit32u slot;
/* Mask increment */
slot = (chip->cycles + 20) % 24;
if (chip->pg_reset[slot])
{
chip->pg_inc[slot] = 0;
}
/* Phase step */
slot = (chip->cycles + 19) % 24;
if (chip->pg_reset[slot] || chip->mode_test_21[3])
{
chip->pg_phase[slot] = 0;
}
chip->pg_phase[slot] += chip->pg_inc[slot];
chip->pg_phase[slot] &= 0xfffff;
}
static void OPN2_EnvelopeSSGEG(ym3438_t *chip)
{
Bit32u slot = chip->cycles;
Bit8u direction = 0;
chip->eg_ssg_pgrst_latch[slot] = 0;
chip->eg_ssg_repeat_latch[slot] = 0;
chip->eg_ssg_hold_up_latch[slot] = 0;
chip->eg_ssg_inv[slot] = 0;
if (chip->ssg_eg[slot] & 0x08)
{
direction = chip->eg_ssg_dir[slot];
if (chip->eg_level[slot] & 0x200)
{
/* Reset */
if ((chip->ssg_eg[slot] & 0x03) == 0x00)
{
chip->eg_ssg_pgrst_latch[slot] = 1;
}
/* Repeat */
if ((chip->ssg_eg[slot] & 0x01) == 0x00)
{
chip->eg_ssg_repeat_latch[slot] = 1;
}
/* Inverse */
if ((chip->ssg_eg[slot] & 0x03) == 0x02)
{
direction ^= 1;
}
if ((chip->ssg_eg[slot] & 0x03) == 0x03)
{
direction = 1;
}
}
/* Hold up */
if (chip->eg_kon_latch[slot]
&& ((chip->ssg_eg[slot] & 0x07) == 0x05 || (chip->ssg_eg[slot] & 0x07) == 0x03))
{
chip->eg_ssg_hold_up_latch[slot] = 1;
}
direction &= chip->eg_kon[slot];
chip->eg_ssg_inv[slot] = (chip->eg_ssg_dir[slot] ^ ((chip->ssg_eg[slot] >> 2) & 0x01))
& chip->eg_kon[slot];
}
chip->eg_ssg_dir[slot] = direction;
chip->eg_ssg_enable[slot] = (chip->ssg_eg[slot] >> 3) & 0x01;
}
static void OPN2_EnvelopeADSR(ym3438_t *chip)
{
Bit32u slot = (chip->cycles + 22) % 24;
Bit8u nkon = chip->eg_kon_latch[slot];
Bit8u okon = chip->eg_kon[slot];
Bit8u kon_event;
Bit8u koff_event;
Bit8u eg_off;
Bit16s level;
Bit16s nextlevel = 0;
Bit16s ssg_level;
Bit8u nextstate = chip->eg_state[slot];
Bit16s inc = 0;
chip->eg_read[0] = chip->eg_read_inc;
chip->eg_read_inc = chip->eg_inc > 0;
/* Reset phase generator */
chip->pg_reset[slot] = (nkon && !okon) || chip->eg_ssg_pgrst_latch[slot];
/* KeyOn/Off */
kon_event = (nkon && !okon) || (okon && chip->eg_ssg_repeat_latch[slot]);
koff_event = okon && !nkon;
ssg_level = level = (Bit16s)chip->eg_level[slot];
if (chip->eg_ssg_inv[slot])
{
/* Inverse */
ssg_level = 512 - level;
ssg_level &= 0x3ff;
}
if (koff_event)
{
level = ssg_level;
}
if (chip->eg_ssg_enable[slot])
{
eg_off = level >> 9;
}
else
{
eg_off = (level & 0x3f0) == 0x3f0;
}
nextlevel = level;
if (kon_event)
{
nextstate = eg_num_attack;
/* Instant attack */
if (chip->eg_ratemax)
{
nextlevel = 0;
}
else if (chip->eg_state[slot] == eg_num_attack && level != 0 && chip->eg_inc && nkon)
{
inc = (~level << chip->eg_inc) >> 5;
}
}
else
{
switch (chip->eg_state[slot])
{
case eg_num_attack:
if (level == 0)
{
nextstate = eg_num_decay;
}
else if(chip->eg_inc && !chip->eg_ratemax && nkon)
{
inc = (~level << chip->eg_inc) >> 5;
}
break;
case eg_num_decay:
if ((level >> 4) == (chip->eg_sl[1] << 1))
{
nextstate = eg_num_sustain;
}
else if (!eg_off && chip->eg_inc)
{
inc = 1 << (chip->eg_inc - 1);
if (chip->eg_ssg_enable[slot])
{
inc <<= 2;
}
}
break;
case eg_num_sustain:
case eg_num_release:
if (!eg_off && chip->eg_inc)
{
inc = 1 << (chip->eg_inc - 1);
if (chip->eg_ssg_enable[slot])
{
inc <<= 2;
}
}
break;
default:
break;
}
if (!nkon)
{
nextstate = eg_num_release;
}
}
if (chip->eg_kon_csm[slot])
{
nextlevel |= chip->eg_tl[1] << 3;
}
/* Envelope off */
if (!kon_event && !chip->eg_ssg_hold_up_latch[slot] && chip->eg_state[slot] != eg_num_attack && eg_off)
{
nextstate = eg_num_release;
nextlevel = 0x3ff;
}
nextlevel += inc;
chip->eg_kon[slot] = chip->eg_kon_latch[slot];
chip->eg_level[slot] = (Bit16u)nextlevel & 0x3ff;
chip->eg_state[slot] = nextstate;
}
static void OPN2_EnvelopePrepare(ym3438_t *chip)
{
Bit8u rate;
Bit8u sum;
Bit8u inc = 0;
Bit32u slot = chip->cycles;
Bit8u rate_sel;
/* Prepare increment */
rate = (chip->eg_rate << 1) + chip->eg_ksv;
if (rate > 0x3f)
{
rate = 0x3f;
}
sum = ((rate >> 2) + chip->eg_shift_lock) & 0x0f;
if (chip->eg_rate != 0 && chip->eg_quotient == 2)
{
if (rate < 48)
{
switch (sum)
{
case 12:
inc = 1;
break;
case 13:
inc = (rate >> 1) & 0x01;
break;
case 14:
inc = rate & 0x01;
break;
default:
break;
}
}
else
{
inc = eg_stephi[rate & 0x03][chip->eg_timer_low_lock] + (rate >> 2) - 11;
if (inc > 4)
{
inc = 4;
}
}
}
chip->eg_inc = inc;
chip->eg_ratemax = (rate >> 1) == 0x1f;
/* Prepare rate & ksv */
rate_sel = chip->eg_state[slot];
if ((chip->eg_kon[slot] && chip->eg_ssg_repeat_latch[slot])
|| (!chip->eg_kon[slot] && chip->eg_kon_latch[slot]))
{
rate_sel = eg_num_attack;
}
switch (rate_sel)
{
case eg_num_attack:
chip->eg_rate = chip->ar[slot];
break;
case eg_num_decay:
chip->eg_rate = chip->dr[slot];
break;
case eg_num_sustain:
chip->eg_rate = chip->sr[slot];
break;
case eg_num_release:
chip->eg_rate = (chip->rr[slot] << 1) | 0x01;
break;
default:
break;
}
chip->eg_ksv = chip->pg_kcode >> (chip->ks[slot] ^ 0x03);
if (chip->am[slot])
{
chip->eg_lfo_am = chip->lfo_am >> eg_am_shift[chip->ams[chip->channel]];
}
else
{
chip->eg_lfo_am = 0;
}
/* Delay TL & SL value */
chip->eg_tl[1] = chip->eg_tl[0];
chip->eg_tl[0] = chip->tl[slot];
chip->eg_sl[1] = chip->eg_sl[0];
chip->eg_sl[0] = chip->sl[slot];
}
static void OPN2_EnvelopeGenerate(ym3438_t *chip)
{
Bit32u slot = (chip->cycles + 23) % 24;
Bit16u level;
level = chip->eg_level[slot];
if (chip->eg_ssg_inv[slot])
{
/* Inverse */
level = 512 - level;
}
if (chip->mode_test_21[5])
{
level = 0;
}
level &= 0x3ff;
/* Apply AM LFO */
level += chip->eg_lfo_am;
/* Apply TL */
if (!(chip->mode_csm && chip->channel == 2 + 1))
{
level += chip->eg_tl[0] << 3;
}
if (level > 0x3ff)
{
level = 0x3ff;
}
chip->eg_out[slot] = level;
}
static void OPN2_UpdateLFO(ym3438_t *chip)
{
if ((chip->lfo_quotient & lfo_cycles[chip->lfo_freq]) == lfo_cycles[chip->lfo_freq])
{
chip->lfo_quotient = 0;
chip->lfo_cnt++;
}
else
{
chip->lfo_quotient += chip->lfo_inc;
}
chip->lfo_cnt &= chip->lfo_en;
}
static void OPN2_FMPrepare(ym3438_t *chip)
{
Bit32u slot = (chip->cycles + 6) % 24;
Bit32u channel = chip->channel;
Bit16s mod, mod1, mod2;
Bit32u op = slot / 6;
Bit8u connect = chip->connect[channel];
Bit32u prevslot = (chip->cycles + 18) % 24;
/* Calculate modulation */
mod1 = mod2 = 0;
if (fm_algorithm[op][0][connect])
{
mod2 |= chip->fm_op1[channel][0];
}
if (fm_algorithm[op][1][connect])
{
mod1 |= chip->fm_op1[channel][1];
}
if (fm_algorithm[op][2][connect])
{
mod1 |= chip->fm_op2[channel];
}
if (fm_algorithm[op][3][connect])
{
mod2 |= chip->fm_out[prevslot];
}
if (fm_algorithm[op][4][connect])
{
mod1 |= chip->fm_out[prevslot];
}
mod = mod1 + mod2;
if (op == 0)
{
/* Feedback */
mod = mod >> (10 - chip->fb[channel]);
if (!chip->fb[channel])
{
mod = 0;
}
}
else
{
mod >>= 1;
}
chip->fm_mod[slot] = mod;
slot = (chip->cycles + 18) % 24;
/* OP1 */
if (slot / 6 == 0)
{
chip->fm_op1[channel][1] = chip->fm_op1[channel][0];
chip->fm_op1[channel][0] = chip->fm_out[slot];
}
/* OP2 */
if (slot / 6 == 2)
{
chip->fm_op2[channel] = chip->fm_out[slot];
}
}
static void OPN2_ChGenerate(ym3438_t *chip)
{
Bit32u slot = (chip->cycles + 18) % 24;
Bit32u channel = chip->channel;
Bit32u op = slot / 6;
Bit32u test_dac = chip->mode_test_2c[5];
Bit16s acc = chip->ch_acc[channel];
Bit16s add = test_dac;
Bit16s sum = 0;
if (op == 0 && !test_dac)
{
acc = 0;
}
if (chip->chip_type & ym3438_mode_opn) {
if (fm_algorithm[op][5][chip->connect[channel]] && !test_dac)
{
add += chip->fm_out[slot];
}
sum = acc + add;
} else {
if (fm_algorithm[op][5][chip->connect[channel]] && !test_dac)
{
add += chip->fm_out[slot] >> 5;
}
sum = acc + add;
/* Clamp */
if (sum > 255)
{
sum = 255;
}
else if(sum < -256)
{
sum = -256;
}
}
if (op == 0 || test_dac)
{
chip->ch_out[channel] = chip->ch_acc[channel];
}
chip->ch_acc[channel] = sum;
}
static void OPN2_ChOutput(ym3438_t *chip)
{
Bit32u cycles = chip->cycles;
Bit32u slot = chip->cycles;
Bit32u channel = chip->channel;
Bit32u test_dac = chip->mode_test_2c[5];
Bit16s out;
Bit16s sign;
Bit32u out_en;
chip->ch_read = chip->ch_lock;
if (slot < 12)
{
/* Ch 4,5,6 */
channel++;
}
if ((cycles & 3) == 0)
{
if (!test_dac)
{
/* Lock value */
chip->ch_lock = chip->ch_out[channel];
}
chip->ch_lock_l = chip->pan_l[channel];
chip->ch_lock_r = chip->pan_r[channel];
}
/* Ch 6 */
if (((cycles >> 2) == 1 && chip->dacen) || test_dac)
{
out = (Bit16s)chip->dacdata;
out = SIGN_EXTEND(8, out);
}
else
{
out = chip->ch_lock;
}
chip->mol = 0;
chip->mor = 0;
if (chip->chip_type & ym3438_mode_ym2612)
{
out_en = ((cycles & 3) == 3) || test_dac;
/* YM2612 DAC emulation(not verified) */
sign = out >> 8;
if (out >= 0)
{
out++;
sign++;
}
if (chip->ch_lock_l && out_en)
{
chip->mol = out;
}
else
{
chip->mol = sign;
}
if (chip->ch_lock_r && out_en)
{
chip->mor = out;
}
else
{
chip->mor = sign;
}
/* Amplify signal */
chip->mol *= 3;
chip->mor *= 3;
}
else
{
out_en = ((cycles & 3) != 0) || test_dac;
if (chip->ch_lock_l && out_en)
{
chip->mol = out;
}
if (chip->ch_lock_r && out_en)
{
chip->mor = out;
}
}
}
static void OPN2_FMGenerate(ym3438_t *chip)
{
Bit32u slot = (chip->cycles + 19) % 24;
/* Calculate phase */
Bit16u phase = (chip->fm_mod[slot] + (chip->pg_phase[slot] >> 10)) & 0x3ff;
Bit16u quarter;
Bit16u level;
Bit16s output;
if (phase & 0x100)
{
quarter = (phase ^ 0xff) & 0xff;
}
else
{
quarter = phase & 0xff;
}
level = logsinrom[quarter];
/* Apply envelope */
level += chip->eg_out[slot] << 2;
/* Transform */
if (level > 0x1fff)
{
level = 0x1fff;
}
output = ((exprom[(level & 0xff) ^ 0xff] | 0x400) << 2) >> (level >> 8);
if (phase & 0x200)
{
output = ((~output) ^ (chip->mode_test_21[4] << 13)) + 1;
}
else
{
output = output ^ (chip->mode_test_21[4] << 13);
}
output = SIGN_EXTEND(13, output);
chip->fm_out[slot] = output;
}
static void OPN2_DoTimerA(ym3438_t *chip)
{
Bit16u time;
Bit8u load;
load = chip->timer_a_overflow;
if (chip->cycles == 2)
{
/* Lock load value */
load |= (!chip->timer_a_load_lock && chip->timer_a_load);
chip->timer_a_load_lock = chip->timer_a_load;
if (chip->mode_csm)
{
/* CSM KeyOn */
chip->mode_kon_csm = load;
}
else
{
chip->mode_kon_csm = 0;
}
}
/* Load counter */
if (chip->timer_a_load_latch)
{
time = chip->timer_a_reg;
}
else
{
time = chip->timer_a_cnt;
}
chip->timer_a_load_latch = load;
/* Increase counter */
if ((chip->cycles == 1 && chip->timer_a_load_lock) || chip->mode_test_21[2])
{
time++;
}
/* Set overflow flag */
if (chip->timer_a_reset)
{
chip->timer_a_reset = 0;
chip->timer_a_overflow_flag = 0;
}
else
{
chip->timer_a_overflow_flag |= chip->timer_a_overflow & chip->timer_a_enable;
}
chip->timer_a_overflow = (time >> 10);
chip->timer_a_cnt = time & 0x3ff;
}
static void OPN2_DoTimerB(ym3438_t *chip)
{
Bit16u time;
Bit8u load;
load = chip->timer_b_overflow;
if (chip->cycles == 2)
{
/* Lock load value */
load |= (!chip->timer_b_load_lock && chip->timer_b_load);
chip->timer_b_load_lock = chip->timer_b_load;
}
/* Load counter */
if (chip->timer_b_load_latch)
{
time = chip->timer_b_reg;
}
else
{
time = chip->timer_b_cnt;
}
chip->timer_b_load_latch = load;
/* Increase counter */
if (chip->cycles == 1)
{
chip->timer_b_subcnt++;
}
if ((chip->timer_b_subcnt == 0x10 && chip->timer_b_load_lock) || chip->mode_test_21[2])
{
time++;
}
chip->timer_b_subcnt &= 0x0f;
/* Set overflow flag */
if (chip->timer_b_reset)
{
chip->timer_b_reset = 0;
chip->timer_b_overflow_flag = 0;
}
else
{
chip->timer_b_overflow_flag |= chip->timer_b_overflow & chip->timer_b_enable;
}
chip->timer_b_overflow = (time >> 8);
chip->timer_b_cnt = time & 0xff;
}
static void OPN2_KeyOn(ym3438_t*chip)
{
Bit32u slot = chip->cycles;
Bit32u chan = chip->channel;
/* Key On */
chip->eg_kon_latch[slot] = chip->mode_kon[slot];
chip->eg_kon_csm[slot] = 0;
if (chip->channel == 2 && chip->mode_kon_csm)
{
/* CSM Key On */
chip->eg_kon_latch[slot] = 1;
chip->eg_kon_csm[slot] = 1;
}
if (chip->cycles == chip->mode_kon_channel)
{
/* OP1 */
chip->mode_kon[chan] = chip->mode_kon_operator[0];
/* OP2 */
chip->mode_kon[chan + 12] = chip->mode_kon_operator[1];
/* OP3 */
chip->mode_kon[chan + 6] = chip->mode_kon_operator[2];
/* OP4 */
chip->mode_kon[chan + 18] = chip->mode_kon_operator[3];
}
}
void OPN2_Reset(ym3438_t *chip)
{
Bit32u i;
memset(chip, 0, sizeof(ym3438_t));
chip->chip_type = ym3438_mode_readmode;
for (i = 0; i < 24; i++)
{
chip->eg_out[i] = 0x3ff;
chip->eg_level[i] = 0x3ff;
chip->eg_state[i] = eg_num_release;
chip->multi[i] = 1;
}
for (i = 0; i < 6; i++)
{
chip->pan_l[i] = 1;
chip->pan_r[i] = 1;
}
}
void OPN2_SetChipType(ym3438_t *chip, Bit32u type)
{
chip->chip_type = type;
}
void OPN2_Clock(ym3438_t *chip, Bit16s *buffer)
{
Bit32u slot = chip->cycles;
chip->lfo_inc = chip->mode_test_21[1];
chip->pg_read >>= 1;
chip->eg_read[1] >>= 1;
chip->eg_cycle++;
/* Lock envelope generator timer value */
if (chip->cycles == 1 && chip->eg_quotient == 2)
{
if (chip->eg_cycle_stop)
{
chip->eg_shift_lock = 0;
}
else
{
chip->eg_shift_lock = chip->eg_shift + 1;
}
chip->eg_timer_low_lock = chip->eg_timer & 0x03;
}
/* Cycle specific functions */
switch (chip->cycles)
{
case 0:
chip->lfo_pm = chip->lfo_cnt >> 2;
if (chip->lfo_cnt & 0x40)
{
chip->lfo_am = chip->lfo_cnt & 0x3f;
}
else
{
chip->lfo_am = chip->lfo_cnt ^ 0x3f;
}
chip->lfo_am <<= 1;
break;
case 1:
chip->eg_quotient++;
chip->eg_quotient %= 3;
chip->eg_cycle = 0;
chip->eg_cycle_stop = 1;
chip->eg_shift = 0;
chip->eg_timer_inc |= chip->eg_quotient >> 1;
chip->eg_timer = chip->eg_timer + chip->eg_timer_inc;
chip->eg_timer_inc = chip->eg_timer >> 12;
chip->eg_timer &= 0xfff;
break;
case 2:
chip->pg_read = chip->pg_phase[21] & 0x3ff;
chip->eg_read[1] = chip->eg_out[0];
break;
case 13:
chip->eg_cycle = 0;
chip->eg_cycle_stop = 1;
chip->eg_shift = 0;
chip->eg_timer = chip->eg_timer + chip->eg_timer_inc;
chip->eg_timer_inc = chip->eg_timer >> 12;
chip->eg_timer &= 0xfff;
break;
case 23:
chip->lfo_inc |= 1;
break;
}
chip->eg_timer &= ~(chip->mode_test_21[5] << chip->eg_cycle);
if (((chip->eg_timer >> chip->eg_cycle) | (chip->pin_test_in & chip->eg_custom_timer)) & chip->eg_cycle_stop)
{
chip->eg_shift = chip->eg_cycle;
chip->eg_cycle_stop = 0;
}
OPN2_DoIO(chip);
OPN2_DoTimerA(chip);
OPN2_DoTimerB(chip);
OPN2_KeyOn(chip);
OPN2_ChOutput(chip);
OPN2_ChGenerate(chip);
OPN2_FMPrepare(chip);
OPN2_FMGenerate(chip);
OPN2_PhaseGenerate(chip);
OPN2_PhaseCalcIncrement(chip);
OPN2_EnvelopeADSR(chip);
OPN2_EnvelopeGenerate(chip);
OPN2_EnvelopeSSGEG(chip);
OPN2_EnvelopePrepare(chip);
/* Prepare fnum & block */
if (chip->mode_ch3)
{
/* Channel 3 special mode */
switch (slot)
{
case 1: /* OP1 */
chip->pg_fnum = chip->fnum_3ch[1];
chip->pg_block = chip->block_3ch[1];
chip->pg_kcode = chip->kcode_3ch[1];
break;
case 7: /* OP3 */
chip->pg_fnum = chip->fnum_3ch[0];
chip->pg_block = chip->block_3ch[0];
chip->pg_kcode = chip->kcode_3ch[0];
break;
case 13: /* OP2 */
chip->pg_fnum = chip->fnum_3ch[2];
chip->pg_block = chip->block_3ch[2];
chip->pg_kcode = chip->kcode_3ch[2];
break;
case 19: /* OP4 */
default:
chip->pg_fnum = chip->fnum[(chip->channel + 1) % 6];
chip->pg_block = chip->block[(chip->channel + 1) % 6];
chip->pg_kcode = chip->kcode[(chip->channel + 1) % 6];
break;
}
}
else
{
chip->pg_fnum = chip->fnum[(chip->channel + 1) % 6];
chip->pg_block = chip->block[(chip->channel + 1) % 6];
chip->pg_kcode = chip->kcode[(chip->channel + 1) % 6];
}
OPN2_UpdateLFO(chip);
OPN2_DoRegWrite(chip);
chip->cycles = (chip->cycles + 1) % 24;
chip->channel = chip->cycles % 6;
buffer[0] = chip->mol;
buffer[1] = chip->mor;
if (chip->status_time)
chip->status_time--;
}
void OPN2_Write(ym3438_t *chip, Bit32u port, Bit8u data)
{
port &= 3;
chip->write_data = ((port << 7) & 0x100) | data;
if (port & 1)
{
/* Data */
chip->write_d |= 1;
}
else
{
/* Address */
chip->write_a |= 1;
}
}
void OPN2_SetTestPin(ym3438_t *chip, Bit32u value)
{
chip->pin_test_in = value & 1;
}
Bit32u OPN2_ReadTestPin(ym3438_t *chip)
{
if (!chip->mode_test_2c[7])
{
return 0;
}
return chip->cycles == 23;
}
Bit32u OPN2_ReadIRQPin(ym3438_t *chip)
{
return chip->timer_a_overflow_flag | chip->timer_b_overflow_flag;
}
Bit8u OPN2_Read(ym3438_t *chip, Bit32u port)
{
if ((port & 3) == 0 || (chip->chip_type & ym3438_mode_readmode))
{
if (chip->mode_test_21[6])
{
/* Read test data */
Bit32u slot = (chip->cycles + 18) % 24;
Bit16u testdata = ((chip->pg_read & 0x01) << 15)
| ((chip->eg_read[chip->mode_test_21[0]] & 0x01) << 14);
if (chip->mode_test_2c[4])
{
testdata |= chip->ch_read & 0x1ff;
}
else
{
testdata |= chip->fm_out[slot] & 0x3fff;
}
if (chip->mode_test_21[7])
{
chip->status = testdata & 0xff;
}
else
{
chip->status = testdata >> 8;
}
}
else
{
chip->status = (chip->busy << 7) | (chip->timer_b_overflow_flag << 1)
| chip->timer_a_overflow_flag;
}
if (chip->chip_type & ym3438_mode_ym2612)
{
chip->status_time = 300000;
}
else
{
chip->status_time = 40000000;
}
}
if (chip->status_time)
{
return chip->status;
}
return 0;
}
Reference in a new issue Copy permalink