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Diffstat (limited to 'src/chips/ymfm/ymfm_fm.ipp')
| -rw-r--r-- | src/chips/ymfm/ymfm_fm.ipp | 1597 |
1 files changed, 1597 insertions, 0 deletions
diff --git a/src/chips/ymfm/ymfm_fm.ipp b/src/chips/ymfm/ymfm_fm.ipp new file mode 100644 index 0000000..fcfffcb --- /dev/null +++ b/src/chips/ymfm/ymfm_fm.ipp @@ -0,0 +1,1597 @@ +// BSD 3-Clause License +// +// Copyright (c) 2021, Aaron Giles +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this +// list of conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE +// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +namespace ymfm +{ + +//********************************************************* +// GLOBAL TABLE LOOKUPS +//********************************************************* + +//------------------------------------------------- +// abs_sin_attenuation - given a sin (phase) input +// where the range 0-2*PI is mapped onto 10 bits, +// return the absolute value of sin(input), +// logarithmically-adjusted and treated as an +// attenuation value, in 4.8 fixed point format +//------------------------------------------------- + +inline uint32_t abs_sin_attenuation(uint32_t input) +{ + // the values here are stored as 4.8 logarithmic values for 1/4 phase + // this matches the internal format of the OPN chip, extracted from the die + static uint16_t const s_sin_table[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 + }; + + // if the top bit is set, we're in the second half of the curve + // which is a mirror image, so invert the index + if (bitfield(input, 8)) + input = ~input; + + // return the value from the table + return s_sin_table[input & 0xff]; +} + + +//------------------------------------------------- +// attenuation_to_volume - given a 5.8 fixed point +// logarithmic attenuation value, return a 13-bit +// linear volume +//------------------------------------------------- + +inline uint32_t attenuation_to_volume(uint32_t input) +{ + // the values here are 10-bit mantissas with an implied leading bit + // this matches the internal format of the OPN chip, extracted from the die + + // as a nod to performance, the implicit 0x400 bit is pre-incorporated, and + // the values are left-shifted by 2 so that a simple right shift is all that + // is needed; also the order is reversed to save a NOT on the input +#define X(a) (((a) | 0x400) << 2) + static uint16_t const s_power_table[256] = + { + X(0x3fa),X(0x3f5),X(0x3ef),X(0x3ea),X(0x3e4),X(0x3df),X(0x3da),X(0x3d4), + X(0x3cf),X(0x3c9),X(0x3c4),X(0x3bf),X(0x3b9),X(0x3b4),X(0x3ae),X(0x3a9), + X(0x3a4),X(0x39f),X(0x399),X(0x394),X(0x38f),X(0x38a),X(0x384),X(0x37f), + X(0x37a),X(0x375),X(0x370),X(0x36a),X(0x365),X(0x360),X(0x35b),X(0x356), + X(0x351),X(0x34c),X(0x347),X(0x342),X(0x33d),X(0x338),X(0x333),X(0x32e), + X(0x329),X(0x324),X(0x31f),X(0x31a),X(0x315),X(0x310),X(0x30b),X(0x306), + X(0x302),X(0x2fd),X(0x2f8),X(0x2f3),X(0x2ee),X(0x2e9),X(0x2e5),X(0x2e0), + X(0x2db),X(0x2d6),X(0x2d2),X(0x2cd),X(0x2c8),X(0x2c4),X(0x2bf),X(0x2ba), + X(0x2b5),X(0x2b1),X(0x2ac),X(0x2a8),X(0x2a3),X(0x29e),X(0x29a),X(0x295), + X(0x291),X(0x28c),X(0x288),X(0x283),X(0x27f),X(0x27a),X(0x276),X(0x271), + X(0x26d),X(0x268),X(0x264),X(0x25f),X(0x25b),X(0x257),X(0x252),X(0x24e), + X(0x249),X(0x245),X(0x241),X(0x23c),X(0x238),X(0x234),X(0x230),X(0x22b), + X(0x227),X(0x223),X(0x21e),X(0x21a),X(0x216),X(0x212),X(0x20e),X(0x209), + X(0x205),X(0x201),X(0x1fd),X(0x1f9),X(0x1f5),X(0x1f0),X(0x1ec),X(0x1e8), + X(0x1e4),X(0x1e0),X(0x1dc),X(0x1d8),X(0x1d4),X(0x1d0),X(0x1cc),X(0x1c8), + X(0x1c4),X(0x1c0),X(0x1bc),X(0x1b8),X(0x1b4),X(0x1b0),X(0x1ac),X(0x1a8), + X(0x1a4),X(0x1a0),X(0x19c),X(0x199),X(0x195),X(0x191),X(0x18d),X(0x189), + X(0x185),X(0x181),X(0x17e),X(0x17a),X(0x176),X(0x172),X(0x16f),X(0x16b), + X(0x167),X(0x163),X(0x160),X(0x15c),X(0x158),X(0x154),X(0x151),X(0x14d), + X(0x149),X(0x146),X(0x142),X(0x13e),X(0x13b),X(0x137),X(0x134),X(0x130), + X(0x12c),X(0x129),X(0x125),X(0x122),X(0x11e),X(0x11b),X(0x117),X(0x114), + X(0x110),X(0x10c),X(0x109),X(0x106),X(0x102),X(0x0ff),X(0x0fb),X(0x0f8), + X(0x0f4),X(0x0f1),X(0x0ed),X(0x0ea),X(0x0e7),X(0x0e3),X(0x0e0),X(0x0dc), + X(0x0d9),X(0x0d6),X(0x0d2),X(0x0cf),X(0x0cc),X(0x0c8),X(0x0c5),X(0x0c2), + X(0x0be),X(0x0bb),X(0x0b8),X(0x0b5),X(0x0b1),X(0x0ae),X(0x0ab),X(0x0a8), + X(0x0a4),X(0x0a1),X(0x09e),X(0x09b),X(0x098),X(0x094),X(0x091),X(0x08e), + X(0x08b),X(0x088),X(0x085),X(0x082),X(0x07e),X(0x07b),X(0x078),X(0x075), + X(0x072),X(0x06f),X(0x06c),X(0x069),X(0x066),X(0x063),X(0x060),X(0x05d), + X(0x05a),X(0x057),X(0x054),X(0x051),X(0x04e),X(0x04b),X(0x048),X(0x045), + X(0x042),X(0x03f),X(0x03c),X(0x039),X(0x036),X(0x033),X(0x030),X(0x02d), + X(0x02a),X(0x028),X(0x025),X(0x022),X(0x01f),X(0x01c),X(0x019),X(0x016), + X(0x014),X(0x011),X(0x00e),X(0x00b),X(0x008),X(0x006),X(0x003),X(0x000) + }; +#undef X + + // look up the fractional part, then shift by the whole + return s_power_table[input & 0xff] >> (input >> 8); +} + + +//------------------------------------------------- +// attenuation_increment - given a 6-bit ADSR +// rate value and a 3-bit stepping index, +// return a 4-bit increment to the attenutaion +// for this step (or for the attack case, the +// fractional scale factor to decrease by) +//------------------------------------------------- + +inline uint32_t attenuation_increment(uint32_t rate, uint32_t index) +{ + static uint32_t const s_increment_table[64] = + { + 0x00000000, 0x00000000, 0x10101010, 0x10101010, // 0-3 (0x00-0x03) + 0x10101010, 0x10101010, 0x11101110, 0x11101110, // 4-7 (0x04-0x07) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 8-11 (0x08-0x0B) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 12-15 (0x0C-0x0F) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 16-19 (0x10-0x13) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 20-23 (0x14-0x17) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 24-27 (0x18-0x1B) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 28-31 (0x1C-0x1F) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 32-35 (0x20-0x23) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 36-39 (0x24-0x27) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 40-43 (0x28-0x2B) + 0x10101010, 0x10111010, 0x11101110, 0x11111110, // 44-47 (0x2C-0x2F) + 0x11111111, 0x21112111, 0x21212121, 0x22212221, // 48-51 (0x30-0x33) + 0x22222222, 0x42224222, 0x42424242, 0x44424442, // 52-55 (0x34-0x37) + 0x44444444, 0x84448444, 0x84848484, 0x88848884, // 56-59 (0x38-0x3B) + 0x88888888, 0x88888888, 0x88888888, 0x88888888 // 60-63 (0x3C-0x3F) + }; + return bitfield(s_increment_table[rate], 4*index, 4); +} + + +//------------------------------------------------- +// detune_adjustment - given a 5-bit key code +// value and a 3-bit detune parameter, return a +// 6-bit signed phase displacement; this table +// has been verified against Nuked's equations, +// but the equations are rather complicated, so +// we'll keep the simplicity of the table +//------------------------------------------------- + +inline int32_t detune_adjustment(uint32_t detune, uint32_t keycode) +{ + static uint8_t const s_detune_adjustment[32][4] = + { + { 0, 0, 1, 2 }, { 0, 0, 1, 2 }, { 0, 0, 1, 2 }, { 0, 0, 1, 2 }, + { 0, 1, 2, 2 }, { 0, 1, 2, 3 }, { 0, 1, 2, 3 }, { 0, 1, 2, 3 }, + { 0, 1, 2, 4 }, { 0, 1, 3, 4 }, { 0, 1, 3, 4 }, { 0, 1, 3, 5 }, + { 0, 2, 4, 5 }, { 0, 2, 4, 6 }, { 0, 2, 4, 6 }, { 0, 2, 5, 7 }, + { 0, 2, 5, 8 }, { 0, 3, 6, 8 }, { 0, 3, 6, 9 }, { 0, 3, 7, 10 }, + { 0, 4, 8, 11 }, { 0, 4, 8, 12 }, { 0, 4, 9, 13 }, { 0, 5, 10, 14 }, + { 0, 5, 11, 16 }, { 0, 6, 12, 17 }, { 0, 6, 13, 19 }, { 0, 7, 14, 20 }, + { 0, 8, 16, 22 }, { 0, 8, 16, 22 }, { 0, 8, 16, 22 }, { 0, 8, 16, 22 } + }; + int32_t result = s_detune_adjustment[keycode][detune & 3]; + return bitfield(detune, 2) ? -result : result; +} + + +//------------------------------------------------- +// opm_key_code_to_phase_step - converts an +// OPM concatenated block (3 bits), keycode +// (4 bits) and key fraction (6 bits) to a 0.10 +// phase step, after applying the given delta; +// this applies to OPM and OPZ, so it lives here +// in a central location +//------------------------------------------------- + +inline uint32_t opm_key_code_to_phase_step(uint32_t block_freq, int32_t delta) +{ + // The phase step is essentially the fnum in OPN-speak. To compute this table, + // we used the standard formula for computing the frequency of a note, and + // then converted that frequency to fnum using the formula documented in the + // YM2608 manual. + // + // However, the YM2608 manual describes everything in terms of a nominal 8MHz + // clock, which produces an FM clock of: + // + // 8000000 / 24(operators) / 6(prescale) = 55555Hz FM clock + // + // Whereas the descriptions for the YM2151 use a nominal 3.579545MHz clock: + // + // 3579545 / 32(operators) / 2(prescale) = 55930Hz FM clock + // + // To correct for this, the YM2608 formula was adjusted to use a clock of + // 8053920Hz, giving this equation for the fnum: + // + // fnum = (double(144) * freq * (1 << 20)) / double(8053920) / 4; + // + // Unfortunately, the computed table differs in a few spots from the data + // verified from an actual chip. The table below comes from David Viens' + // analysis, used with his permission. + static const uint32_t s_phase_step[12*64] = + { + 41568,41600,41632,41664,41696,41728,41760,41792,41856,41888,41920,41952,42016,42048,42080,42112, + 42176,42208,42240,42272,42304,42336,42368,42400,42464,42496,42528,42560,42624,42656,42688,42720, + 42784,42816,42848,42880,42912,42944,42976,43008,43072,43104,43136,43168,43232,43264,43296,43328, + 43392,43424,43456,43488,43552,43584,43616,43648,43712,43744,43776,43808,43872,43904,43936,43968, + 44032,44064,44096,44128,44192,44224,44256,44288,44352,44384,44416,44448,44512,44544,44576,44608, + 44672,44704,44736,44768,44832,44864,44896,44928,44992,45024,45056,45088,45152,45184,45216,45248, + 45312,45344,45376,45408,45472,45504,45536,45568,45632,45664,45728,45760,45792,45824,45888,45920, + 45984,46016,46048,46080,46144,46176,46208,46240,46304,46336,46368,46400,46464,46496,46528,46560, + 46656,46688,46720,46752,46816,46848,46880,46912,46976,47008,47072,47104,47136,47168,47232,47264, + 47328,47360,47392,47424,47488,47520,47552,47584,47648,47680,47744,47776,47808,47840,47904,47936, + 48032,48064,48096,48128,48192,48224,48288,48320,48384,48416,48448,48480,48544,48576,48640,48672, + 48736,48768,48800,48832,48896,48928,48992,49024,49088,49120,49152,49184,49248,49280,49344,49376, + 49440,49472,49504,49536,49600,49632,49696,49728,49792,49824,49856,49888,49952,49984,50048,50080, + 50144,50176,50208,50240,50304,50336,50400,50432,50496,50528,50560,50592,50656,50688,50752,50784, + 50880,50912,50944,50976,51040,51072,51136,51168,51232,51264,51328,51360,51424,51456,51488,51520, + 51616,51648,51680,51712,51776,51808,51872,51904,51968,52000,52064,52096,52160,52192,52224,52256, + 52384,52416,52448,52480,52544,52576,52640,52672,52736,52768,52832,52864,52928,52960,52992,53024, + 53120,53152,53216,53248,53312,53344,53408,53440,53504,53536,53600,53632,53696,53728,53792,53824, + 53920,53952,54016,54048,54112,54144,54208,54240,54304,54336,54400,54432,54496,54528,54592,54624, + 54688,54720,54784,54816,54880,54912,54976,55008,55072,55104,55168,55200,55264,55296,55360,55392, + 55488,55520,55584,55616,55680,55712,55776,55808,55872,55936,55968,56032,56064,56128,56160,56224, + 56288,56320,56384,56416,56480,56512,56576,56608,56672,56736,56768,56832,56864,56928,56960,57024, + 57120,57152,57216,57248,57312,57376,57408,57472,57536,57568,57632,57664,57728,57792,57824,57888, + 57952,57984,58048,58080,58144,58208,58240,58304,58368,58400,58464,58496,58560,58624,58656,58720, + 58784,58816,58880,58912,58976,59040,59072,59136,59200,59232,59296,59328,59392,59456,59488,59552, + 59648,59680,59744,59776,59840,59904,59936,60000,60064,60128,60160,60224,60288,60320,60384,60416, + 60512,60544,60608,60640,60704,60768,60800,60864,60928,60992,61024,61088,61152,61184,61248,61280, + 61376,61408,61472,61536,61600,61632,61696,61760,61824,61856,61920,61984,62048,62080,62144,62208, + 62272,62304,62368,62432,62496,62528,62592,62656,62720,62752,62816,62880,62944,62976,63040,63104, + 63200,63232,63296,63360,63424,63456,63520,63584,63648,63680,63744,63808,63872,63904,63968,64032, + 64096,64128,64192,64256,64320,64352,64416,64480,64544,64608,64672,64704,64768,64832,64896,64928, + 65024,65056,65120,65184,65248,65312,65376,65408,65504,65536,65600,65664,65728,65792,65856,65888, + 65984,66016,66080,66144,66208,66272,66336,66368,66464,66496,66560,66624,66688,66752,66816,66848, + 66944,66976,67040,67104,67168,67232,67296,67328,67424,67456,67520,67584,67648,67712,67776,67808, + 67904,67936,68000,68064,68128,68192,68256,68288,68384,68448,68512,68544,68640,68672,68736,68800, + 68896,68928,68992,69056,69120,69184,69248,69280,69376,69440,69504,69536,69632,69664,69728,69792, + 69920,69952,70016,70080,70144,70208,70272,70304,70400,70464,70528,70560,70656,70688,70752,70816, + 70912,70976,71040,71104,71136,71232,71264,71360,71424,71488,71552,71616,71648,71744,71776,71872, + 71968,72032,72096,72160,72192,72288,72320,72416,72480,72544,72608,72672,72704,72800,72832,72928, + 72992,73056,73120,73184,73216,73312,73344,73440,73504,73568,73632,73696,73728,73824,73856,73952, + 74080,74144,74208,74272,74304,74400,74432,74528,74592,74656,74720,74784,74816,74912,74944,75040, + 75136,75200,75264,75328,75360,75456,75488,75584,75648,75712,75776,75840,75872,75968,76000,76096, + 76224,76288,76352,76416,76448,76544,76576,76672,76736,76800,76864,76928,77024,77120,77152,77248, + 77344,77408,77472,77536,77568,77664,77696,77792,77856,77920,77984,78048,78144,78240,78272,78368, + 78464,78528,78592,78656,78688,78784,78816,78912,78976,79040,79104,79168,79264,79360,79392,79488, + 79616,79680,79744,79808,79840,79936,79968,80064,80128,80192,80256,80320,80416,80512,80544,80640, + 80768,80832,80896,80960,80992,81088,81120,81216,81280,81344,81408,81472,81568,81664,81696,81792, + 81952,82016,82080,82144,82176,82272,82304,82400,82464,82528,82592,82656,82752,82848,82880,82976 + }; + + // extract the block (octave) first + uint32_t block = bitfield(block_freq, 10, 3); + + // the keycode (bits 6-9) is "gappy", mapping 12 values over 16 in each + // octave; to correct for this, we multiply the 4-bit value by 3/4 (or + // rather subtract 1/4); note that a (invalid) value of 15 will bleed into + // the next octave -- this is confirmed + uint32_t adjusted_code = bitfield(block_freq, 6, 4) - bitfield(block_freq, 8, 2); + + // now re-insert the 6-bit fraction + int32_t eff_freq = (adjusted_code << 6) | bitfield(block_freq, 0, 6); + + // now that the gaps are removed, add the delta + eff_freq += delta; + + // handle over/underflow by adjusting the block: + if (uint32_t(eff_freq) >= 768) + { + // minimum delta is -512 (PM), so we can only underflow by 1 octave + if (eff_freq < 0) + { + eff_freq += 768; + if (block-- == 0) + return s_phase_step[0] >> 7; + } + + // maximum delta is +512+608 (PM+detune), so we can overflow by up to 2 octaves + else + { + eff_freq -= 768; + if (eff_freq >= 768) + block++, eff_freq -= 768; + if (block++ >= 7) + return s_phase_step[767]; + } + } + + // look up the phase shift for the key code, then shift by octave + return s_phase_step[eff_freq] >> (block ^ 7); +} + + +//------------------------------------------------- +// opn_lfo_pm_phase_adjustment - given the 7 most +// significant frequency number bits, plus a 3-bit +// PM depth value and a signed 5-bit raw PM value, +// return a signed PM adjustment to the frequency; +// algorithm written to match Nuked behavior +//------------------------------------------------- + +inline int32_t opn_lfo_pm_phase_adjustment(uint32_t fnum_bits, uint32_t pm_sensitivity, int32_t lfo_raw_pm) +{ + // this table encodes 2 shift values to apply to the top 7 bits + // of fnum; it is effectively a cheap multiply by a constant + // value containing 0-2 bits + static uint8_t const s_lfo_pm_shifts[8][8] = + { + { 0x77, 0x77, 0x77, 0x77, 0x77, 0x77, 0x77, 0x77 }, + { 0x77, 0x77, 0x77, 0x77, 0x72, 0x72, 0x72, 0x72 }, + { 0x77, 0x77, 0x77, 0x72, 0x72, 0x72, 0x17, 0x17 }, + { 0x77, 0x77, 0x72, 0x72, 0x17, 0x17, 0x12, 0x12 }, + { 0x77, 0x77, 0x72, 0x17, 0x17, 0x17, 0x12, 0x07 }, + { 0x77, 0x77, 0x17, 0x12, 0x07, 0x07, 0x02, 0x01 }, + { 0x77, 0x77, 0x17, 0x12, 0x07, 0x07, 0x02, 0x01 }, + { 0x77, 0x77, 0x17, 0x12, 0x07, 0x07, 0x02, 0x01 } + }; + + // look up the relevant shifts + int32_t abs_pm = (lfo_raw_pm < 0) ? -lfo_raw_pm : lfo_raw_pm; + uint32_t const shifts = s_lfo_pm_shifts[pm_sensitivity][bitfield(abs_pm, 0, 3)]; + + // compute the adjustment + int32_t adjust = (fnum_bits >> bitfield(shifts, 0, 4)) + (fnum_bits >> bitfield(shifts, 4, 4)); + if (pm_sensitivity > 5) + adjust <<= pm_sensitivity - 5; + adjust >>= 2; + + // every 16 cycles it inverts sign + return (lfo_raw_pm < 0) ? -adjust : adjust; +} + + + +//********************************************************* +// FM OPERATOR +//********************************************************* + +//------------------------------------------------- +// fm_operator - constructor +//------------------------------------------------- + +template<class RegisterType> +fm_operator<RegisterType>::fm_operator(fm_engine_base<RegisterType> &owner, uint32_t opoffs) : + m_choffs(0), + m_opoffs(opoffs), + m_phase(0), + m_env_attenuation(0x3ff), + m_env_state(EG_RELEASE), + m_ssg_inverted(false), + m_key_state(0), + m_keyon_live(0), + m_regs(owner.regs()), + m_owner(owner) +{ +} + + +//------------------------------------------------- +// reset - reset the channel state +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::reset() +{ + // reset our data + m_phase = 0; + m_env_attenuation = 0x3ff; + m_env_state = EG_RELEASE; + m_ssg_inverted = 0; + m_key_state = 0; + m_keyon_live = 0; +} + + +//------------------------------------------------- +// save_restore - save or restore the data +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::save_restore(ymfm_saved_state &state) +{ + state.save_restore(m_phase); + state.save_restore(m_env_attenuation); + state.save_restore(m_env_state); + state.save_restore(m_ssg_inverted); + state.save_restore(m_key_state); + state.save_restore(m_keyon_live); +} + + +//------------------------------------------------- +// prepare - prepare for clocking +//------------------------------------------------- + +template<class RegisterType> +bool fm_operator<RegisterType>::prepare() +{ + // cache the data + m_regs.cache_operator_data(m_choffs, m_opoffs, m_cache); + + // clock the key state + clock_keystate(uint32_t(m_keyon_live != 0)); + m_keyon_live &= ~(1 << KEYON_CSM); + + // we're active until we're quiet after the release + return (m_env_state != (RegisterType::EG_HAS_REVERB ? EG_REVERB : EG_RELEASE) || m_env_attenuation < EG_QUIET); +} + + +//------------------------------------------------- +// clock - master clocking function +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::clock(uint32_t env_counter, int32_t lfo_raw_pm) +{ + // clock the SSG-EG state (OPN/OPNA) + if (m_regs.op_ssg_eg_enable(m_opoffs)) + clock_ssg_eg_state(); + else + m_ssg_inverted = false; + + // clock the envelope if on an envelope cycle; env_counter is a x.2 value + if (bitfield(env_counter, 0, 2) == 0) + clock_envelope(env_counter >> 2); + + // clock the phase + clock_phase(lfo_raw_pm); +} + + +//------------------------------------------------- +// compute_volume - compute the 14-bit signed +// volume of this operator, given a phase +// modulation and an AM LFO offset +//------------------------------------------------- + +template<class RegisterType> +int32_t fm_operator<RegisterType>::compute_volume(uint32_t phase, uint32_t am_offset) const +{ + // the low 10 bits of phase represents a full 2*PI period over + // the full sin wave + + // early out if the envelope is effectively off + if (m_env_attenuation > EG_QUIET) + return 0; + + // get the absolute value of the sin, as attenuation, as a 4.8 fixed point value + uint32_t sin_attenuation = m_cache.waveform[phase & (RegisterType::WAVEFORM_LENGTH - 1)]; + + // get the attenuation from the evelope generator as a 4.6 value, shifted up to 4.8 + uint32_t env_attenuation = envelope_attenuation(am_offset) << 2; + + // combine into a 5.8 value, then convert from attenuation to 13-bit linear volume + int32_t result = attenuation_to_volume((sin_attenuation & 0x7fff) + env_attenuation); + + // negate if in the negative part of the sin wave (sign bit gives 14 bits) + return bitfield(sin_attenuation, 15) ? -result : result; +} + + +//------------------------------------------------- +// compute_noise_volume - compute the 14-bit +// signed noise volume of this operator, given a +// noise input value and an AM offset +//------------------------------------------------- + +template<class RegisterType> +int32_t fm_operator<RegisterType>::compute_noise_volume(uint32_t am_offset) const +{ + // application manual says the logarithmic transform is not applied here, so we + // just use the raw envelope attenuation, inverted (since 0 attenuation should be + // maximum), and shift it up from a 10-bit value to an 11-bit value + int32_t result = (envelope_attenuation(am_offset) ^ 0x3ff) << 1; + + // QUESTION: is AM applied still? + + // negate based on the noise state + return bitfield(m_regs.noise_state(), 0) ? -result : result; +} + + +//------------------------------------------------- +// keyonoff - signal a key on/off event +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::keyonoff(uint32_t on, keyon_type type) +{ + m_keyon_live = (m_keyon_live & ~(1 << int(type))) | (bitfield(on, 0) << int(type)); +} + + +//------------------------------------------------- +// start_attack - start the attack phase; called +// when a keyon happens or when an SSG-EG cycle +// is complete and restarts +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::start_attack(bool is_restart) +{ + // don't change anything if already in attack state + if (m_env_state == EG_ATTACK) + return; + m_env_state = EG_ATTACK; + + // generally not inverted at start, except if SSG-EG is enabled and + // one of the inverted modes is specified; leave this alone on a + // restart, as it is managed by the clock_ssg_eg_state() code + if (RegisterType::EG_HAS_SSG && !is_restart) + m_ssg_inverted = m_regs.op_ssg_eg_enable(m_opoffs) & bitfield(m_regs.op_ssg_eg_mode(m_opoffs), 2); + + // reset the phase when we start an attack due to a key on + // (but not when due to an SSG-EG restart except in certain cases + // managed directly by the SSG-EG code) + if (!is_restart) + m_phase = 0; + + // if the attack rate >= 62 then immediately go to max attenuation + if (m_cache.eg_rate[EG_ATTACK] >= 62) + m_env_attenuation = 0; +} + + +//------------------------------------------------- +// start_release - start the release phase; +// called when a keyoff happens +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::start_release() +{ + // don't change anything if already in release state + if (m_env_state >= EG_RELEASE) + return; + m_env_state = EG_RELEASE; + + // if attenuation if inverted due to SSG-EG, snap the inverted attenuation + // as the starting point + if (RegisterType::EG_HAS_SSG && m_ssg_inverted) + { + m_env_attenuation = (0x200 - m_env_attenuation) & 0x3ff; + m_ssg_inverted = false; + } +} + + +//------------------------------------------------- +// clock_keystate - clock the keystate to match +// the incoming keystate +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::clock_keystate(uint32_t keystate) +{ + assert(keystate == 0 || keystate == 1); + + // has the key changed? + if ((keystate ^ m_key_state) != 0) + { + m_key_state = keystate; + + // if the key has turned on, start the attack + if (keystate != 0) + { + // OPLL has a DP ("depress"?) state to bring the volume + // down before starting the attack + if (RegisterType::EG_HAS_DEPRESS && m_env_attenuation < 0x200) + m_env_state = EG_DEPRESS; + else + start_attack(); + } + + // otherwise, start the release + else + start_release(); + } +} + + +//------------------------------------------------- +// clock_ssg_eg_state - clock the SSG-EG state; +// should only be called if SSG-EG is enabled +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::clock_ssg_eg_state() +{ + // work only happens once the attenuation crosses above 0x200 + if (!bitfield(m_env_attenuation, 9)) + return; + + // 8 SSG-EG modes: + // 000: repeat normally + // 001: run once, hold low + // 010: repeat, alternating between inverted/non-inverted + // 011: run once, hold high + // 100: inverted repeat normally + // 101: inverted run once, hold low + // 110: inverted repeat, alternating between inverted/non-inverted + // 111: inverted run once, hold high + uint32_t mode = m_regs.op_ssg_eg_mode(m_opoffs); + + // hold modes (1/3/5/7) + if (bitfield(mode, 0)) + { + // set the inverted flag to the end state (0 for modes 1/7, 1 for modes 3/5) + m_ssg_inverted = bitfield(mode, 2) ^ bitfield(mode, 1); + + // if holding, force the attenuation to the expected value once we're + // past the attack phase + if (m_env_state != EG_ATTACK) + m_env_attenuation = m_ssg_inverted ? 0x200 : 0x3ff; + } + + // continuous modes (0/2/4/6) + else + { + // toggle invert in alternating mode (even in attack state) + m_ssg_inverted ^= bitfield(mode, 1); + + // restart attack if in decay/sustain states + if (m_env_state == EG_DECAY || m_env_state == EG_SUSTAIN) + start_attack(true); + + // phase is reset to 0 in modes 0/4 + if (bitfield(mode, 1) == 0) + m_phase = 0; + } + + // in all modes, once we hit release state, attenuation is forced to maximum + if (m_env_state == EG_RELEASE) + m_env_attenuation = 0x3ff; +} + + +//------------------------------------------------- +// clock_envelope - clock the envelope state +// according to the given count +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::clock_envelope(uint32_t env_counter) +{ + // handle attack->decay transitions + if (m_env_state == EG_ATTACK && m_env_attenuation == 0) + m_env_state = EG_DECAY; + + // handle decay->sustain transitions; it is important to do this immediately + // after the attack->decay transition above in the event that the sustain level + // is set to 0 (in which case we will skip right to sustain without doing any + // decay); as an example where this can be heard, check the cymbals sound + // in channel 0 of shinobi's test mode sound #5 + if (m_env_state == EG_DECAY && m_env_attenuation >= m_cache.eg_sustain) + m_env_state = EG_SUSTAIN; + + // fetch the appropriate 6-bit rate value from the cache + uint32_t rate = m_cache.eg_rate[m_env_state]; + + // compute the rate shift value; this is the shift needed to + // apply to the env_counter such that it becomes a 5.11 fixed + // point number + uint32_t rate_shift = rate >> 2; + env_counter <<= rate_shift; + + // see if the fractional part is 0; if not, it's not time to clock + if (bitfield(env_counter, 0, 11) != 0) + return; + + // determine the increment based on the non-fractional part of env_counter + uint32_t relevant_bits = bitfield(env_counter, (rate_shift <= 11) ? 11 : rate_shift, 3); + uint32_t increment = attenuation_increment(rate, relevant_bits); + + // attack is the only one that increases + if (m_env_state == EG_ATTACK) + { + // glitch means that attack rates of 62/63 don't increment if + // changed after the initial key on (where they are handled + // specially); nukeykt confirms this happens on OPM, OPN, OPL/OPLL + // at least so assuming it is true for everyone + if (rate < 62) + m_env_attenuation += (~m_env_attenuation * increment) >> 4; + } + + // all other cases are similar + else + { + // non-SSG-EG cases just apply the increment + if (!m_regs.op_ssg_eg_enable(m_opoffs)) + m_env_attenuation += increment; + + // SSG-EG only applies if less than mid-point, and then at 4x + else if (m_env_attenuation < 0x200) + m_env_attenuation += 4 * increment; + + // clamp the final attenuation + if (m_env_attenuation >= 0x400) + m_env_attenuation = 0x3ff; + + // transition from depress to attack + if (RegisterType::EG_HAS_DEPRESS && m_env_state == EG_DEPRESS && m_env_attenuation >= 0x200) + start_attack(); + + // transition from release to reverb, should switch at -18dB + if (RegisterType::EG_HAS_REVERB && m_env_state == EG_RELEASE && m_env_attenuation >= 0xc0) + m_env_state = EG_REVERB; + } +} + + +//------------------------------------------------- +// clock_phase - clock the 10.10 phase value; the +// OPN version of the logic has been verified +// against the Nuked phase generator +//------------------------------------------------- + +template<class RegisterType> +void fm_operator<RegisterType>::clock_phase(int32_t lfo_raw_pm) +{ + // read from the cache, or recalculate if PM active + uint32_t phase_step = m_cache.phase_step; + if (phase_step == opdata_cache::PHASE_STEP_DYNAMIC) + phase_step = m_regs.compute_phase_step(m_choffs, m_opoffs, m_cache, lfo_raw_pm); + + // finally apply the step to the current phase value + m_phase += phase_step; +} + + +//------------------------------------------------- +// envelope_attenuation - return the effective +// attenuation of the envelope +//------------------------------------------------- + +template<class RegisterType> +uint32_t fm_operator<RegisterType>::envelope_attenuation(uint32_t am_offset) const +{ + uint32_t result = m_env_attenuation >> m_cache.eg_shift; + + // invert if necessary due to SSG-EG + if (RegisterType::EG_HAS_SSG && m_ssg_inverted) + result = (0x200 - result) & 0x3ff; + + // add in LFO AM modulation + if (m_regs.op_lfo_am_enable(m_opoffs)) + result += am_offset; + + // add in total level and KSL from the cache + result += m_cache.total_level; + + // clamp to max, apply shift, and return + return std::min<uint32_t>(result, 0x3ff); +} + + + +//********************************************************* +// FM CHANNEL +//********************************************************* + +//------------------------------------------------- +// fm_channel - constructor +//------------------------------------------------- + +template<class RegisterType> +fm_channel<RegisterType>::fm_channel(fm_engine_base<RegisterType> &owner, uint32_t choffs) : + m_choffs(choffs), + m_feedback{ 0, 0 }, + m_feedback_in(0), + m_op{ nullptr, nullptr, nullptr, nullptr }, + m_regs(owner.regs()), + m_owner(owner) +{ +} + + +//------------------------------------------------- +// reset - reset the channel state +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::reset() +{ + // reset our data + m_feedback[0] = m_feedback[1] = 0; + m_feedback_in = 0; +} + + +//------------------------------------------------- +// save_restore - save or restore the data +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::save_restore(ymfm_saved_state &state) +{ + state.save_restore(m_feedback[0]); + state.save_restore(m_feedback[1]); + state.save_restore(m_feedback_in); +} + + +//------------------------------------------------- +// keyonoff - signal key on/off to our operators +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::keyonoff(uint32_t states, keyon_type type, uint32_t chnum) +{ + for (uint32_t opnum = 0; opnum < array_size(m_op); opnum++) + if (m_op[opnum] != nullptr) + m_op[opnum]->keyonoff(bitfield(states, opnum), type); + + if (debug::LOG_KEYON_EVENTS && ((debug::GLOBAL_FM_CHANNEL_MASK >> chnum) & 1) != 0) + for (uint32_t opnum = 0; opnum < array_size(m_op); opnum++) + if (m_op[opnum] != nullptr) + debug::log_keyon("%c%s\n", bitfield(states, opnum) ? '+' : '-', m_regs.log_keyon(m_choffs, m_op[opnum]->opoffs()).c_str()); +} + + +//------------------------------------------------- +// prepare - prepare for clocking +//------------------------------------------------- + +template<class RegisterType> +bool fm_channel<RegisterType>::prepare() +{ + uint32_t active_mask = 0; + + // prepare all operators and determine if they are active + for (uint32_t opnum = 0; opnum < array_size(m_op); opnum++) + if (m_op[opnum] != nullptr) + if (m_op[opnum]->prepare()) + active_mask |= 1 << opnum; + + return (active_mask != 0); +} + + +//------------------------------------------------- +// clock - master clock of all operators +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::clock(uint32_t env_counter, int32_t lfo_raw_pm) +{ + // clock the feedback through + m_feedback[0] = m_feedback[1]; + m_feedback[1] = m_feedback_in; + + for (uint32_t opnum = 0; opnum < array_size(m_op); opnum++) + if (m_op[opnum] != nullptr) + m_op[opnum]->clock(env_counter, lfo_raw_pm); + +/* +useful temporary code for envelope debugging +if (m_choffs == 0x101) +{ + for (uint32_t opnum = 0; opnum < array_size(m_op); opnum++) + { + auto &op = *m_op[((opnum & 1) << 1) | ((opnum >> 1) & 1)]; + printf(" %c%03X%c%c ", + "PADSRV"[op.debug_eg_state()], + op.debug_eg_attenuation(), + op.debug_ssg_inverted() ? '-' : '+', + m_regs.op_ssg_eg_enable(op.opoffs()) ? '0' + m_regs.op_ssg_eg_mode(op.opoffs()) : ' '); + } +printf(" -- "); +} +*/ +} + + +//------------------------------------------------- +// output_2op - combine 4 operators according to +// the specified algorithm, returning a sum +// according to the rshift and clipmax parameters, +// which vary between different implementations +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::output_2op(output_data &output, uint32_t rshift, int32_t clipmax) const +{ + // The first 2 operators should be populated + assert(m_op[0] != nullptr); + assert(m_op[1] != nullptr); + + // AM amount is the same across all operators; compute it once + uint32_t am_offset = m_regs.lfo_am_offset(m_choffs); + + // operator 1 has optional self-feedback + int32_t opmod = 0; + uint32_t feedback = m_regs.ch_feedback(m_choffs); + if (feedback != 0) + opmod = (m_feedback[0] + m_feedback[1]) >> (10 - feedback); + + // compute the 14-bit volume/value of operator 1 and update the feedback + int32_t op1value = m_feedback_in = m_op[0]->compute_volume(m_op[0]->phase() + opmod, am_offset); + + // now that the feedback has been computed, skip the rest if all volumes + // are clear; no need to do all this work for nothing + if (m_regs.ch_output_any(m_choffs) == 0) + return; + + // Algorithms for two-operator case: + // 0: O1 -> O2 -> out + // 1: (O1 + O2) -> out + int32_t result; + if (bitfield(m_regs.ch_algorithm(m_choffs), 0) == 0) + { + // some OPL chips use the previous sample for modulation instead of + // the current sample + opmod = (RegisterType::MODULATOR_DELAY ? m_feedback[1] : op1value) >> 1; + result = m_op[1]->compute_volume(m_op[1]->phase() + opmod, am_offset) >> rshift; + } + else + { + result = (RegisterType::MODULATOR_DELAY ? m_feedback[1] : op1value) >> rshift; + result += m_op[1]->compute_volume(m_op[1]->phase(), am_offset) >> rshift; + int32_t clipmin = -clipmax - 1; + result = clamp(result, clipmin, clipmax); + } + + // add to the output + add_to_output(m_choffs, output, result); +} + + +//------------------------------------------------- +// output_4op - combine 4 operators according to +// the specified algorithm, returning a sum +// according to the rshift and clipmax parameters, +// which vary between different implementations +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::output_4op(output_data &output, uint32_t rshift, int32_t clipmax) const +{ + // all 4 operators should be populated + assert(m_op[0] != nullptr); + assert(m_op[1] != nullptr); + assert(m_op[2] != nullptr); + assert(m_op[3] != nullptr); + + // AM amount is the same across all operators; compute it once + uint32_t am_offset = m_regs.lfo_am_offset(m_choffs); + + // operator 1 has optional self-feedback + int32_t opmod = 0; + uint32_t feedback = m_regs.ch_feedback(m_choffs); + if (feedback != 0) + opmod = (m_feedback[0] + m_feedback[1]) >> (10 - feedback); + + // compute the 14-bit volume/value of operator 1 and update the feedback + int32_t op1value = m_feedback_in = m_op[0]->compute_volume(m_op[0]->phase() + opmod, am_offset); + + // now that the feedback has been computed, skip the rest if all volumes + // are clear; no need to do all this work for nothing + if (m_regs.ch_output_any(m_choffs) == 0) + return; + + // OPM/OPN offer 8 different connection algorithms for 4 operators, + // and OPL3 offers 4 more, which we designate here as 8-11. + // + // The operators are computed in order, with the inputs pulled from + // an array of values (opout) that is populated as we go: + // 0 = 0 + // 1 = O1 + // 2 = O2 + // 3 = O3 + // 4 = (O4) + // 5 = O1+O2 + // 6 = O1+O3 + // 7 = O2+O3 + // + // The s_algorithm_ops table describes the inputs and outputs of each + // algorithm as follows: + // + // ---------x use opout[x] as operator 2 input + // ------xxx- use opout[x] as operator 3 input + // ---xxx---- use opout[x] as operator 4 input + // --x------- include opout[1] in final sum + // -x-------- include opout[2] in final sum + // x--------- include opout[3] in final sum + #define ALGORITHM(op2in, op3in, op4in, op1out, op2out, op3out) \ + ((op2in) | ((op3in) << 1) | ((op4in) << 4) | ((op1out) << 7) | ((op2out) << 8) | ((op3out) << 9)) + static uint16_t const s_algorithm_ops[8+4] = + { + ALGORITHM(1,2,3, 0,0,0), // 0: O1 -> O2 -> O3 -> O4 -> out (O4) + ALGORITHM(0,5,3, 0,0,0), // 1: (O1 + O2) -> O3 -> O4 -> out (O4) + ALGORITHM(0,2,6, 0,0,0), // 2: (O1 + (O2 -> O3)) -> O4 -> out (O4) + ALGORITHM(1,0,7, 0,0,0), // 3: ((O1 -> O2) + O3) -> O4 -> out (O4) + ALGORITHM(1,0,3, 0,1,0), // 4: ((O1 -> O2) + (O3 -> O4)) -> out (O2+O4) + ALGORITHM(1,1,1, 0,1,1), // 5: ((O1 -> O2) + (O1 -> O3) + (O1 -> O4)) -> out (O2+O3+O4) + ALGORITHM(1,0,0, 0,1,1), // 6: ((O1 -> O2) + O3 + O4) -> out (O2+O3+O4) + ALGORITHM(0,0,0, 1,1,1), // 7: (O1 + O2 + O3 + O4) -> out (O1+O2+O3+O4) + ALGORITHM(1,2,3, 0,0,0), // 8: O1 -> O2 -> O3 -> O4 -> out (O4) [same as 0] + ALGORITHM(0,2,3, 1,0,0), // 9: (O1 + (O2 -> O3 -> O4)) -> out (O1+O4) [unique] + ALGORITHM(1,0,3, 0,1,0), // 10: ((O1 -> O2) + (O3 -> O4)) -> out (O2+O4) [same as 4] + ALGORITHM(0,2,0, 1,0,1) // 11: (O1 + (O2 -> O3) + O4) -> out (O1+O3+O4) [unique] + }; + uint32_t algorithm_ops = s_algorithm_ops[m_regs.ch_algorithm(m_choffs)]; + + // populate the opout table + int16_t opout[8]; + opout[0] = 0; + opout[1] = op1value; + + // compute the 14-bit volume/value of operator 2 + opmod = opout[bitfield(algorithm_ops, 0, 1)] >> 1; + opout[2] = m_op[1]->compute_volume(m_op[1]->phase() + opmod, am_offset); + opout[5] = opout[1] + opout[2]; + + // compute the 14-bit volume/value of operator 3 + opmod = opout[bitfield(algorithm_ops, 1, 3)] >> 1; + opout[3] = m_op[2]->compute_volume(m_op[2]->phase() + opmod, am_offset); + opout[6] = opout[1] + opout[3]; + opout[7] = opout[2] + opout[3]; + + // compute the 14-bit volume/value of operator 4; this could be a noise + // value on the OPM; all algorithms consume OP4 output at a minimum + int32_t result; + if (m_regs.noise_enable() && m_choffs == 7) + result = m_op[3]->compute_noise_volume(am_offset); + else + { + opmod = opout[bitfield(algorithm_ops, 4, 3)] >> 1; + result = m_op[3]->compute_volume(m_op[3]->phase() + opmod, am_offset); + } + result >>= rshift; + + // optionally add OP1, OP2, OP3 + int32_t clipmin = -clipmax - 1; + if (bitfield(algorithm_ops, 7) != 0) + result = clamp(result + (opout[1] >> rshift), clipmin, clipmax); + if (bitfield(algorithm_ops, 8) != 0) + result = clamp(result + (opout[2] >> rshift), clipmin, clipmax); + if (bitfield(algorithm_ops, 9) != 0) + result = clamp(result + (opout[3] >> rshift), clipmin, clipmax); + + // add to the output + add_to_output(m_choffs, output, result); +} + + +//------------------------------------------------- +// output_rhythm_ch6 - special case output +// computation for OPL channel 6 in rhythm mode, +// which outputs a Bass Drum instrument +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::output_rhythm_ch6(output_data &output, uint32_t rshift, int32_t clipmax) const +{ + (void)clipmax; + // AM amount is the same across all operators; compute it once + uint32_t am_offset = m_regs.lfo_am_offset(m_choffs); + + // Bass Drum: this uses operators 12 and 15 (i.e., channel 6) + // in an almost-normal way, except that if the algorithm is 1, + // the first operator is ignored instead of added in + + // operator 1 has optional self-feedback + int32_t opmod = 0; + uint32_t feedback = m_regs.ch_feedback(m_choffs); + if (feedback != 0) + opmod = (m_feedback[0] + m_feedback[1]) >> (10 - feedback); + + // compute the 14-bit volume/value of operator 1 and update the feedback + int32_t opout1 = m_feedback_in = m_op[0]->compute_volume(m_op[0]->phase() + opmod, am_offset); + + // compute the 14-bit volume/value of operator 2, which is the result + opmod = bitfield(m_regs.ch_algorithm(m_choffs), 0) ? 0 : (opout1 >> 1); + int32_t result = m_op[1]->compute_volume(m_op[1]->phase() + opmod, am_offset) >> rshift; + + // add to the output + add_to_output(m_choffs, output, result * 2); +} + + +//------------------------------------------------- +// output_rhythm_ch7 - special case output +// computation for OPL channel 7 in rhythm mode, +// which outputs High Hat and Snare Drum +// instruments +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::output_rhythm_ch7(uint32_t phase_select, output_data &output, uint32_t rshift, int32_t clipmax) const +{ + // AM amount is the same across all operators; compute it once + uint32_t am_offset = m_regs.lfo_am_offset(m_choffs); + uint32_t noise_state = bitfield(m_regs.noise_state(), 0); + + // High Hat: this uses the envelope from operator 13 (channel 7), + // and a combination of noise and the operator 13/17 phase select + // to compute the phase + uint32_t phase = (phase_select << 9) | (0xd0 >> (2 * (noise_state ^ phase_select))); + int32_t result = m_op[0]->compute_volume(phase, am_offset) >> rshift; + + // Snare Drum: this uses the envelope from operator 16 (channel 7), + // and a combination of noise and operator 13 phase to pick a phase + uint32_t op13phase = m_op[0]->phase(); + phase = (0x100 << bitfield(op13phase, 8)) ^ (noise_state << 8); + result += m_op[1]->compute_volume(phase, am_offset) >> rshift; + result = clamp(result, -clipmax - 1, clipmax); + + // add to the output + add_to_output(m_choffs, output, result * 2); +} + + +//------------------------------------------------- +// output_rhythm_ch8 - special case output +// computation for OPL channel 8 in rhythm mode, +// which outputs Tom Tom and Top Cymbal instruments +//------------------------------------------------- + +template<class RegisterType> +void fm_channel<RegisterType>::output_rhythm_ch8(uint32_t phase_select, output_data &output, uint32_t rshift, int32_t clipmax) const +{ + // AM amount is the same across all operators; compute it once + uint32_t am_offset = m_regs.lfo_am_offset(m_choffs); + + // Tom Tom: this is just a single operator processed normally + int32_t result = m_op[0]->compute_volume(m_op[0]->phase(), am_offset) >> rshift; + + // Top Cymbal: this uses the envelope from operator 17 (channel 8), + // and the operator 13/17 phase select to compute the phase + uint32_t phase = 0x100 | (phase_select << 9); + result += m_op[1]->compute_volume(phase, am_offset) >> rshift; + result = clamp(result, -clipmax - 1, clipmax); + + // add to the output + add_to_output(m_choffs, output, result * 2); +} + + + +//********************************************************* +// FM ENGINE BASE +//********************************************************* + +//------------------------------------------------- +// fm_engine_base - constructor +//------------------------------------------------- + +template<class RegisterType> +fm_engine_base<RegisterType>::fm_engine_base(ymfm_interface &intf) : + m_intf(intf), + m_env_counter(0), + m_status(0), + m_clock_prescale(RegisterType::DEFAULT_PRESCALE), + m_irq_mask(STATUS_TIMERA | STATUS_TIMERB), + m_irq_state(0), + m_timer_running{0,0}, + m_total_clocks(0), + m_active_channels(ALL_CHANNELS), + m_modified_channels(ALL_CHANNELS), + m_prepare_count(0) +{ + // inform the interface of their engine + m_intf.m_engine = this; + + // create the channels + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + m_channel[chnum] = std::make_unique<fm_channel<RegisterType>>(*this, RegisterType::channel_offset(chnum)); + + // create the operators + for (uint32_t opnum = 0; opnum < OPERATORS; opnum++) + m_operator[opnum] = std::make_unique<fm_operator<RegisterType>>(*this, RegisterType::operator_offset(opnum)); + +#if (YMFM_DEBUG_LOG_WAVFILES) + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + m_wavfile[chnum].set_index(chnum); +#endif + + // do the initial operator assignment + assign_operators(); +} + + +//------------------------------------------------- +// reset - reset the overall state +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::reset() +{ + // reset all status bits + set_reset_status(0, 0xff); + + // register type-specific initialization + m_regs.reset(); + + // explicitly write to the mode register since it has side-effects + // QUESTION: old cores initialize this to 0x30 -- who is right? + write(RegisterType::REG_MODE, 0); + + // reset the channels + for (auto &chan : m_channel) + chan->reset(); + + // reset the operators + for (auto &op : m_operator) + op->reset(); +} + + +//------------------------------------------------- +// save_restore - save or restore the data +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::save_restore(ymfm_saved_state &state) +{ + // save our data + state.save_restore(m_env_counter); + state.save_restore(m_status); + state.save_restore(m_clock_prescale); + state.save_restore(m_irq_mask); + state.save_restore(m_irq_state); + state.save_restore(m_timer_running[0]); + state.save_restore(m_timer_running[1]); + state.save_restore(m_total_clocks); + + // save the register/family data + m_regs.save_restore(state); + + // save channel data + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + m_channel[chnum]->save_restore(state); + + // save operator data + for (uint32_t opnum = 0; opnum < OPERATORS; opnum++) + m_operator[opnum]->save_restore(state); + + // invalidate any caches + invalidate_caches(); +} + + +//------------------------------------------------- +// clock - iterate over all channels, clocking +// them forward one step +//------------------------------------------------- + +template<class RegisterType> +uint32_t fm_engine_base<RegisterType>::clock(uint32_t chanmask) +{ + // update the clock counter + m_total_clocks++; + + // if something was modified, prepare + // also prepare every 4k samples to catch ending notes + if (m_modified_channels != 0 || m_prepare_count++ >= 4096) + { + // reassign operators to channels if dynamic + if (RegisterType::DYNAMIC_OPS) + assign_operators(); + + // call each channel to prepare + m_active_channels = 0; + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + if (bitfield(chanmask, chnum)) + if (m_channel[chnum]->prepare()) + m_active_channels |= 1 << chnum; + + // reset the modified channels and prepare count + m_modified_channels = m_prepare_count = 0; + } + + // if the envelope clock divider is 1, just increment by 4; + // otherwise, increment by 1 and manually wrap when we reach the divide count + if (RegisterType::EG_CLOCK_DIVIDER == 1) + m_env_counter += 4; + else if (bitfield(++m_env_counter, 0, 2) == RegisterType::EG_CLOCK_DIVIDER) + m_env_counter += 4 - RegisterType::EG_CLOCK_DIVIDER; + + // clock the noise generator + int32_t lfo_raw_pm = m_regs.clock_noise_and_lfo(); + + // now update the state of all the channels and operators + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + if (bitfield(chanmask, chnum)) + m_channel[chnum]->clock(m_env_counter, lfo_raw_pm); + + // return the envelope counter as it is used to clock ADPCM-A + return m_env_counter; +} + + +//------------------------------------------------- +// output - compute a sum over the relevant +// channels +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::output(output_data &output, uint32_t rshift, int32_t clipmax, uint32_t chanmask) const +{ + // mask out some channels for debug purposes + chanmask &= debug::GLOBAL_FM_CHANNEL_MASK; + + // mask out inactive channels + if (!YMFM_DEBUG_LOG_WAVFILES) + chanmask &= m_active_channels; + + // handle the rhythm case, where some of the operators are dedicated + // to percussion (this is an OPL-specific feature) + if (m_regs.rhythm_enable()) + { + // we don't support the OPM noise channel here; ensure it is off + assert(m_regs.noise_enable() == 0); + + // precompute the operator 13+17 phase selection value + uint32_t op13phase = m_operator[13]->phase(); + uint32_t op17phase = m_operator[17]->phase(); + uint32_t phase_select = (bitfield(op13phase, 2) ^ bitfield(op13phase, 7)) | bitfield(op13phase, 3) | (bitfield(op17phase, 5) ^ bitfield(op17phase, 3)); + + // sum over all the desired channels + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + if (bitfield(chanmask, chnum)) + { +#if (YMFM_DEBUG_LOG_WAVFILES) + auto reference = output; +#endif + if (chnum == 6) + m_channel[chnum]->output_rhythm_ch6(output, rshift, clipmax); + else if (chnum == 7) + m_channel[chnum]->output_rhythm_ch7(phase_select, output, rshift, clipmax); + else if (chnum == 8) + m_channel[chnum]->output_rhythm_ch8(phase_select, output, rshift, clipmax); + else if (m_channel[chnum]->is4op()) + m_channel[chnum]->output_4op(output, rshift, clipmax); + else + m_channel[chnum]->output_2op(output, rshift, clipmax); +#if (YMFM_DEBUG_LOG_WAVFILES) + m_wavfile[chnum].add(output, reference); +#endif + } + } + else + { + // sum over all the desired channels + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + if (bitfield(chanmask, chnum)) + { +#if (YMFM_DEBUG_LOG_WAVFILES) + auto reference = output; +#endif + if (m_channel[chnum]->is4op()) + m_channel[chnum]->output_4op(output, rshift, clipmax); + else + m_channel[chnum]->output_2op(output, rshift, clipmax); +#if (YMFM_DEBUG_LOG_WAVFILES) + m_wavfile[chnum].add(output, reference); +#endif + } + } +} + + +//------------------------------------------------- +// write - handle writes to the OPN registers +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::write(uint16_t regnum, uint8_t data) +{ + debug::log_fm_write("%03X = %02X\n", regnum, data); + + // special case: writes to the mode register can impact IRQs; + // schedule these writes to ensure ordering with timers + if (regnum == RegisterType::REG_MODE) + { + m_intf.ymfm_sync_mode_write(data); + return; + } + + // for now just mark all channels as modified + m_modified_channels = ALL_CHANNELS; + + // most writes are passive, consumed only when needed + uint32_t keyon_channel; + uint32_t keyon_opmask; + if (m_regs.write(regnum, data, keyon_channel, keyon_opmask)) + { + // handle writes to the keyon register(s) + if (keyon_channel < CHANNELS) + { + // normal channel on/off + m_channel[keyon_channel]->keyonoff(keyon_opmask, KEYON_NORMAL, keyon_channel); + } + else if (CHANNELS >= 9 && keyon_channel == RegisterType::RHYTHM_CHANNEL) + { + // special case for the OPL rhythm channels + m_channel[6]->keyonoff(bitfield(keyon_opmask, 4) ? 3 : 0, KEYON_RHYTHM, 6); + m_channel[7]->keyonoff(bitfield(keyon_opmask, 0) | (bitfield(keyon_opmask, 3) << 1), KEYON_RHYTHM, 7); + m_channel[8]->keyonoff(bitfield(keyon_opmask, 2) | (bitfield(keyon_opmask, 1) << 1), KEYON_RHYTHM, 8); + } + } +} + + +//------------------------------------------------- +// status - return the current state of the +// status flags +//------------------------------------------------- + +template<class RegisterType> +uint8_t fm_engine_base<RegisterType>::status() const +{ + return m_status & ~STATUS_BUSY & ~m_regs.status_mask(); +} + + +//------------------------------------------------- +// assign_operators - get the current mapping of +// operators to channels and assign them all +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::assign_operators() +{ + typename RegisterType::operator_mapping map; + m_regs.operator_map(map); + + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + for (uint32_t index = 0; index < 4; index++) + { + uint32_t opnum = bitfield(map.chan[chnum], 8 * index, 8); + m_channel[chnum]->assign(index, (opnum == 0xff) ? nullptr : m_operator[opnum].get()); + } +} + + +//------------------------------------------------- +// update_timer - update the state of the given +// timer +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::update_timer(uint32_t tnum, uint32_t enable, int32_t delta_clocks) +{ + if (tnum >= 2) + return; + + // if the timer is live, but not currently enabled, set the timer + if (enable && !m_timer_running[tnum]) + { + // period comes from the registers, and is different for each + uint32_t period = (tnum == 0) ? (1024 - m_regs.timer_a_value()) : 16 * (256 - m_regs.timer_b_value()); + + // caller can also specify a delta to account for other effects + period += delta_clocks; + + // reset it + m_intf.ymfm_set_timer(tnum, period * OPERATORS * m_clock_prescale); + m_timer_running[tnum] = 1; + } + + // if the timer is not live, ensure it is not enabled + else if (!enable) + { + m_intf.ymfm_set_timer(tnum, -1); + m_timer_running[tnum] = 0; + } +} + + +//------------------------------------------------- +// engine_timer_expired - timer has expired - signal +// status and possibly IRQs +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::engine_timer_expired(uint32_t tnum) +{ + if (tnum >= 2) + return; + + // update status + if (tnum == 0 && m_regs.enable_timer_a()) + set_reset_status(STATUS_TIMERA, 0); + else if (tnum == 1 && m_regs.enable_timer_b()) + set_reset_status(STATUS_TIMERB, 0); + + // if timer A fired in CSM mode, trigger CSM on all relevant channels + if (tnum == 0 && m_regs.csm()) + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + if (bitfield(RegisterType::CSM_TRIGGER_MASK, chnum)) + { + m_channel[chnum]->keyonoff(1, KEYON_CSM, chnum); + m_modified_channels |= 1 << chnum; + } + + // reset + m_timer_running[tnum] = false; + update_timer(tnum, 1, 0); +} + + +//------------------------------------------------- +// check_interrupts - check the interrupt sources +// for interrupts +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::engine_check_interrupts() +{ + // update the state + uint8_t old_state = m_irq_state; + m_irq_state = ((m_status & m_irq_mask & ~m_regs.status_mask()) != 0); + + // set the IRQ status bit + if (m_irq_state) + m_status |= STATUS_IRQ; + else + m_status &= ~STATUS_IRQ; + + // if changed, signal the new state + if (old_state != m_irq_state) + m_intf.ymfm_update_irq(m_irq_state ? true : false); +} + + +//------------------------------------------------- +// engine_mode_write - handle a mode register write +// via timer callback +//------------------------------------------------- + +template<class RegisterType> +void fm_engine_base<RegisterType>::engine_mode_write(uint8_t data) +{ + // mark all channels as modified + m_modified_channels = ALL_CHANNELS; + + // actually write the mode register now + uint32_t dummy1, dummy2; + m_regs.write(RegisterType::REG_MODE, data, dummy1, dummy2); + + // reset IRQ status -- when written, all other bits are ignored + // QUESTION: should this maybe just reset the IRQ bit and not all the bits? + // That is, check_interrupts would only set, this would only clear? + if (m_regs.irq_reset()) + set_reset_status(0, 0x78); + else + { + // reset timer status + uint8_t reset_mask = 0; + if (m_regs.reset_timer_b()) + reset_mask |= RegisterType::STATUS_TIMERB; + if (m_regs.reset_timer_a()) + reset_mask |= RegisterType::STATUS_TIMERA; + set_reset_status(0, reset_mask); + + // load timers; note that timer B gets a small negative adjustment because + // the *16 multiplier is free-running, so the first tick of the clock + // is a bit shorter + update_timer(1, m_regs.load_timer_b(), -(m_total_clocks & 15)); + update_timer(0, m_regs.load_timer_a(), 0); + } +} + +} |