From 1d4e6ab2bd844d3f51f58d2422914e64f811a1a7 Mon Sep 17 00:00:00 2001 From: Gordon JC Pearce Date: Mon, 9 Sep 2024 00:55:14 +0100 Subject: [PATCH] PWM LFO working --- plugin/chassis.cpp | 1 + plugin/digital.cpp | 87 +++++++++++++++++++++++++++--- plugin/parameters.cpp | 2 +- plugin/voice.cpp | 21 ++++---- plugin/voice.hpp | 123 ++++++++++++++++++++++++++---------------- 5 files changed, 169 insertions(+), 65 deletions(-) diff --git a/plugin/chassis.cpp b/plugin/chassis.cpp index 7db0978..9b206bb 100644 --- a/plugin/chassis.cpp +++ b/plugin/chassis.cpp @@ -121,6 +121,7 @@ void Chassis::run(const float **, float **outputs, uint32_t frames, const MidiEv doMidi(midiEvents, midiEventCount, framePos + s.blockLeft); // printf("compute params and reset block size\n"); + s.runLFO(); for (uint32_t i = 0; i < NUM_VOICES; i++) { s.voice[i].gate(s); diff --git a/plugin/digital.cpp b/plugin/digital.cpp index 7533005..a26677e 100644 --- a/plugin/digital.cpp +++ b/plugin/digital.cpp @@ -1,14 +1,34 @@ -#include "voice.hpp" +/* + Chassis polysynth framework + + Copyright 2024 Gordon JC Pearce + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY + SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION + OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +// contains the emulation of the digital bits #include +#include + +#include "voice.hpp" bool Voice::isFree() { return ff10 == false; } void Voice::on(uint32_t key, bool reset = 0) { - // printf("======================================================================================\n"); // what's with the crazy private variables and all the gotos with crazy labels? // this code emulates the 78C11 code directly (probably inefficiently) // to allow for documenting what the variables actually do @@ -35,8 +55,6 @@ h0144: if (!ff11) goto h0132; // unsure, copied from ff10 at start of mainloop h0149: - // printf("after 0144h, %d %x %x %x %x\n", note, ff07, ff10, ff11, ff33); - // this is in the wrong place really but is the equivalent of programming the counter // and VCO ramp DAC omega = (261.63 * powf(2, (note - 60) / 12.0f)) / 48000.0f; @@ -48,12 +66,8 @@ void Voice::off() { if (!sustain) { // dummy sustain ff33 = false; } - - // printf("after note off, %d %x %x %x %x\n", note, ff07, ff10, ff11, ff33); } - - void Voice::gate(Synth &s) { uint16_t bc, ea = env; @@ -113,3 +127,60 @@ h0590: env = ea; // printf("%04x %d %d %d %d %d \n", ea, ff07, ff08, ff10, ff11, ff33); } + +void Synth::runLFO() { + // compute a loop's worth of LFO + + uint16_t a, b, c, d; + uint16_t bc, hl, ea, tos; + + // 074e + ea = ff4d; // lfo value + bc = lfoRateTable[patchRam.lfoRate]; + + if (!(ff4a & 0x01)) goto h078b; + + ea -= bc; + if (ea < bc) goto h079a; +h075f: + ff4d = ea; + if (!(ff4a & 0x02)) goto h07a2; + + // 0765 + bc = ea; + ea = 0x2000; + ea -= bc; +h076b: + bc = ea; + if (patchRam.switch2 & 0x01) { + bc = 0x3fff; + } + + bc = (bc * patchRam.pwmLfo) >> 7; + bc = 0x3fff - bc; + if (!(patchRam.switch1 & 0x08)) bc = 0x0000; // square off + ff4f = bc; + + // 078a + goto h07a9; + +h078b: + ea += bc; + if (ea & 0xe000) { + ea = 0x1fff; + ff4a++; + } + goto h075f; + +h079a: + ea = 0; + ff4a++; + goto h075f; + +h07a2: + ea += 0x2000; + goto h076b; + +h07a9: + return; +} \ No newline at end of file diff --git a/plugin/parameters.cpp b/plugin/parameters.cpp index 12555ed..b539b57 100644 --- a/plugin/parameters.cpp +++ b/plugin/parameters.cpp @@ -265,7 +265,7 @@ void Chassis::setParameterValue(uint32_t index, float value) { s.patchRam.vcoLfo = value; break; case paramPWMLFO: - s.patchRam.pwmLfo = value; + s.patchRam.pwmLfo = value/1.27; break; case paramSub: s.patchRam.sub = value; diff --git a/plugin/voice.cpp b/plugin/voice.cpp index 1497452..f9abc4d 100644 --- a/plugin/voice.cpp +++ b/plugin/voice.cpp @@ -16,13 +16,12 @@ CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ +// contains the actual sound generation code + #include "voice.hpp" - -#include - #include - +#include static inline float poly3blep0(float t) { float t2 = t * t; @@ -39,15 +38,16 @@ void Voice::run(Synth &s, float *buffer, uint32_t samples) { // 325, because it needs PW to be from 0 to 0.5 // but really the control range is limited from 0 to 100 // there's a resistor on the panel board to sprag the range - float pw = 0.5 - s.patchRam.pwmLfo/325.0f; + float pw = s.ff4f / 32768.0f; - float sqr = (s.patchRam.switch1 & 0x08) ? 0.175 : 0; + + float sqr = 0.175; float saw = (s.patchRam.switch1 & 0x10) ? 0.220 : 0; float sub = (s.patchRam.sub / 127.0f) * 0.275; float gain = 0.5 * powf(2, (s.patchRam.vca / 64.0f) - 1); - float vcaEnv = (s.patchRam.switch2 & 0x04)?(float)ff11:(env / 16384.0f); + float vcaEnv = (s.patchRam.switch2 & 0x04) ? (float)ff11 : (env / 16384.0f); for (uint32_t i = 0; i < samples; i++) { y = delay; @@ -61,10 +61,10 @@ void Voice::run(Synth &s, float *buffer, uint32_t samples) { while (true) { if (pulseStage == 0) { if (phase < pw) break; -#if 1 +#if 0 t = (phase - pw) / omega; #else - t = (phase - pw) / (widthDelay - pw + freq); + t = (phase - pw) / (lastpw - pw + omega); #endif y -= poly3blep0(t) * sqr; delay -= poly3blep1(t) * sqr; @@ -97,7 +97,8 @@ void Voice::run(Synth &s, float *buffer, uint32_t samples) { out = y; // widthDelay = pw; - vr58c106 += ((vcaEnv- vr58c106) * 0.0075); + vr58c106 += ((vcaEnv - vr58c106) * 0.0075); + lastpw = pw; buffer[i] += (gain * out * vr58c106); } } diff --git a/plugin/voice.hpp b/plugin/voice.hpp index cc55dc5..fb119dc 100644 --- a/plugin/voice.hpp +++ b/plugin/voice.hpp @@ -24,12 +24,6 @@ class Synth; -class Patch { - public: - float saw, sqr, sub; - uint16_t attack, decay, sustain, release; -}; - class Voice { public: // uint8_t note = 72; @@ -55,11 +49,11 @@ class Voice { K_ON, K_SUSTAIN } keyState = K_OFF; - bool ff00 = 0; // reset bit - bool ff07 = 0; // status bit - bool ff08 = 0; // set to indicate attack phase complete + bool ff00 = 0; // reset DCO clock flag + bool ff07 = 0; // set to indicate attack phase + bool ff08 = 0; // set to indicate decay/sustain phase bool ff10 = 0; // note on bit - bool ff11 = 0; // sustain flag + bool ff11 = 0; // drives the "gate" signal for VCA bool ff33 = 0; // releasing flag uint16_t env; @@ -69,52 +63,60 @@ class Voice { float delay; uint8_t pulseStage = 0; - float pw_rc = 0; + float lastpw = 0; float vr58c106 = 0; uint16_t attack_table[128] = { - 0x4000, 0x2000, 0x1000, 0x0aaa, 0x0800, 0x0666, 0x0555, 0x0492, 0x0400, - 0x038e, 0x0333, 0x02e9, 0x02ab, 0x0276, 0x0249, 0x0222, 0x0200, 0x01e2, - 0x01c7, 0x01af, 0x0199, 0x0186, 0x0174, 0x0164, 0x0155, 0x0148, 0x013b, - 0x012f, 0x0124, 0x011a, 0x0111, 0x0108, 0x0100, 0x00f8, 0x00f1, 0x00ea, - 0x00e4, 0x00dd, 0x00d8, 0x00d2, 0x00cd, 0x00c8, 0x00c3, 0x00bf, 0x00ba, - 0x00b6, 0x00b2, 0x00ae, 0x00ab, 0x00a7, 0x00a4, 0x00a1, 0x009e, 0x009b, - 0x0098, 0x0095, 0x0092, 0x0090, 0x008d, 0x008b, 0x0089, 0x0086, 0x0084, - 0x0082, 0x007f, 0x007d, 0x007a, 0x0077, 0x0074, 0x0072, 0x006f, 0x006c, - 0x0069, 0x0067, 0x0064, 0x0061, 0x005e, 0x005c, 0x0059, 0x0056, 0x0053, - 0x0050, 0x004e, 0x004b, 0x0048, 0x0045, 0x0042, 0x0040, 0x003f, 0x003d, - 0x003c, 0x003a, 0x0039, 0x0037, 0x0036, 0x0034, 0x0033, 0x0031, 0x0030, - 0x002e, 0x002d, 0x002b, 0x002a, 0x0028, 0x0027, 0x0025, 0x0024, 0x0022, - 0x0021, 0x0021, 0x0020, 0x0020, 0x001f, 0x001f, 0x001e, 0x001e, 0x001d, - 0x001d, 0x001c, 0x001c, 0x001b, 0x001b, 0x001a, 0x0019, 0x0018, 0x0017, - 0x0016, 0x0015}; + 0x4000, 0x2000, 0x1000, 0x0aaa, 0x0800, 0x0666, 0x0555, 0x0492, 0x0400, + 0x038e, 0x0333, 0x02e9, 0x02ab, 0x0276, 0x0249, 0x0222, 0x0200, 0x01e2, + 0x01c7, 0x01af, 0x0199, 0x0186, 0x0174, 0x0164, 0x0155, 0x0148, 0x013b, + 0x012f, 0x0124, 0x011a, 0x0111, 0x0108, 0x0100, 0x00f8, 0x00f1, 0x00ea, + 0x00e4, 0x00dd, 0x00d8, 0x00d2, 0x00cd, 0x00c8, 0x00c3, 0x00bf, 0x00ba, + 0x00b6, 0x00b2, 0x00ae, 0x00ab, 0x00a7, 0x00a4, 0x00a1, 0x009e, 0x009b, + 0x0098, 0x0095, 0x0092, 0x0090, 0x008d, 0x008b, 0x0089, 0x0086, 0x0084, + 0x0082, 0x007f, 0x007d, 0x007a, 0x0077, 0x0074, 0x0072, 0x006f, 0x006c, + 0x0069, 0x0067, 0x0064, 0x0061, 0x005e, 0x005c, 0x0059, 0x0056, 0x0053, + 0x0050, 0x004e, 0x004b, 0x0048, 0x0045, 0x0042, 0x0040, 0x003f, 0x003d, + 0x003c, 0x003a, 0x0039, 0x0037, 0x0036, 0x0034, 0x0033, 0x0031, 0x0030, + 0x002e, 0x002d, 0x002b, 0x002a, 0x0028, 0x0027, 0x0025, 0x0024, 0x0022, + 0x0021, 0x0021, 0x0020, 0x0020, 0x001f, 0x001f, 0x001e, 0x001e, 0x001d, + 0x001d, 0x001c, 0x001c, 0x001b, 0x001b, 0x001a, 0x0019, 0x0018, 0x0017, + 0x0016, 0x0015}; -uint16_t decay_table[128] = { - 0x1000, 0x3000, 0x5000, 0x7000, 0x9000, 0xa000, 0xa800, 0xb000, 0xb800, - 0xc000, 0xc800, 0xd000, 0xd800, 0xe000, 0xe800, 0xf000, 0xf080, 0xf100, - 0xf180, 0xf200, 0xf280, 0xf300, 0xf380, 0xf400, 0xf480, 0xf500, 0xf580, - 0xf600, 0xf680, 0xf700, 0xf780, 0xf800, 0xf880, 0xf900, 0xf980, 0xfa00, - 0xfa80, 0xfb00, 0xfb80, 0xfc00, 0xfc80, 0xfd00, 0xfd80, 0xfe00, 0xfe0c, - 0xfe18, 0xfe24, 0xfe30, 0xfe3c, 0xfe48, 0xfe54, 0xfe60, 0xfe6c, 0xfe78, - 0xfe84, 0xfe90, 0xfe9c, 0xfea8, 0xfeb4, 0xfec0, 0xfecc, 0xfed8, 0xfee4, - 0xfef0, 0xfefc, 0xff08, 0xff0c, 0xff10, 0xff14, 0xff18, 0xff1c, 0xff20, - 0xff24, 0xff28, 0xff2c, 0xff30, 0xff34, 0xff38, 0xff3c, 0xff40, 0xff44, - 0xff48, 0xff4c, 0xff50, 0xff54, 0xff58, 0xff5c, 0xff60, 0xff64, 0xff68, - 0xff6c, 0xff70, 0xff74, 0xff78, 0xff7c, 0xff80, 0xff84, 0xff88, 0xff8c, - 0xff90, 0xff94, 0xff98, 0xff9c, 0xffa0, 0xffa4, 0xffa8, 0xffac, 0xffb0, - 0xffb4, 0xffb8, 0xffbc, 0xffc0, 0xffc4, 0xffc8, 0xffcc, 0xffd0, 0xffd4, - 0xffd8, 0xffdc, 0xffe0, 0xffe4, 0xffe8, 0xffec, 0xfff0, 0xfff1, 0xfff2, - 0xfff3, 0xfff4}; + uint16_t decay_table[128] = { + 0x1000, 0x3000, 0x5000, 0x7000, 0x9000, 0xa000, 0xa800, 0xb000, 0xb800, + 0xc000, 0xc800, 0xd000, 0xd800, 0xe000, 0xe800, 0xf000, 0xf080, 0xf100, + 0xf180, 0xf200, 0xf280, 0xf300, 0xf380, 0xf400, 0xf480, 0xf500, 0xf580, + 0xf600, 0xf680, 0xf700, 0xf780, 0xf800, 0xf880, 0xf900, 0xf980, 0xfa00, + 0xfa80, 0xfb00, 0xfb80, 0xfc00, 0xfc80, 0xfd00, 0xfd80, 0xfe00, 0xfe0c, + 0xfe18, 0xfe24, 0xfe30, 0xfe3c, 0xfe48, 0xfe54, 0xfe60, 0xfe6c, 0xfe78, + 0xfe84, 0xfe90, 0xfe9c, 0xfea8, 0xfeb4, 0xfec0, 0xfecc, 0xfed8, 0xfee4, + 0xfef0, 0xfefc, 0xff08, 0xff0c, 0xff10, 0xff14, 0xff18, 0xff1c, 0xff20, + 0xff24, 0xff28, 0xff2c, 0xff30, 0xff34, 0xff38, 0xff3c, 0xff40, 0xff44, + 0xff48, 0xff4c, 0xff50, 0xff54, 0xff58, 0xff5c, 0xff60, 0xff64, 0xff68, + 0xff6c, 0xff70, 0xff74, 0xff78, 0xff7c, 0xff80, 0xff84, 0xff88, 0xff8c, + 0xff90, 0xff94, 0xff98, 0xff9c, 0xffa0, 0xffa4, 0xffa8, 0xffac, 0xffb0, + 0xffb4, 0xffb8, 0xffbc, 0xffc0, 0xffc4, 0xffc8, 0xffcc, 0xffd0, 0xffd4, + 0xffd8, 0xffdc, 0xffe0, 0xffe4, 0xffe8, 0xffec, 0xfff0, 0xfff1, 0xfff2, + 0xfff3, 0xfff4}; }; - class Synth { public: - Patch patch; Voice voice[8]; float lfo = 0, lfosw = 0.01; float lastpw = 0; uint32_t blockLeft; uint32_t framesLeft = 0; + uint8_t ff1e; + uint8_t ff4a; // LFO flags + uint16_t ff4d = 0; // LFO output value + uint16_t ff4f; // computed PWM LFO + uint16_t ff51; // computed pitch LFO + uint16_t ff53; // computed VCF LFO + uint16_t ff56; // LFO Delay envelope + uint16_t ff5a; // LFO Delay holdoff + uint8_t ff64; // LFO mod sens amount + // okay, not the greatest, this right here // this struct contains the bytes that make up a Juno 106 patch in // sysex order, exactly as they'd be transmitted or received by a @@ -142,6 +144,35 @@ class Synth { uint8_t switch1 = 26; uint8_t switch2 = 24; } patchRam; + + uint8_t lfoDepthTable[128] = { + 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, + 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, + 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, + 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, + 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, + 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x40, 0x42, 0x44, 0x46, 0x48, 0x4a, 0x4c, + 0x4e, 0x50, 0x52, 0x54, 0x56, 0x58, 0x5a, 0x5c, 0x5e, 0x60, 0x62, 0x64, + 0x66, 0x68, 0x6a, 0x6c, 0x6e, 0x70, 0x72, 0x74, 0x76, 0x78, 0x7a, 0x7c, + 0x80, 0x84, 0x88, 0x8c, 0x90, 0x94, 0x98, 0x9c, 0xa0, 0xa4, 0xa8, 0xac, + 0xb0, 0xb4, 0xb8, 0xbc, 0xc0, 0xc4, 0xc8, 0xcc, 0xd0, 0xd4, 0xd8, 0xdc, + 0xe0, 0xe4, 0xe8, 0xec, 0xf0, 0xf8, 0xff, 0xff}; + uint16_t lfoRateTable[128] = { + 0x0005, 0x000f, 0x0019, 0x0028, 0x0037, 0x0046, 0x0050, 0x005a, 0x0064, + 0x006e, 0x0078, 0x0082, 0x008c, 0x0096, 0x00a0, 0x00aa, 0x00b4, 0x00be, + 0x00c8, 0x00d2, 0x00dc, 0x00e6, 0x00f0, 0x00fa, 0x0104, 0x010e, 0x0118, + 0x0122, 0x012c, 0x0136, 0x0140, 0x014a, 0x0154, 0x015e, 0x0168, 0x0172, + 0x017c, 0x0186, 0x0190, 0x019a, 0x01a4, 0x01ae, 0x01b8, 0x01c2, 0x01cc, + 0x01d6, 0x01e0, 0x01ea, 0x01f4, 0x01fe, 0x0208, 0x0212, 0x021c, 0x0226, + 0x0230, 0x023a, 0x0244, 0x024e, 0x0258, 0x0262, 0x026c, 0x0276, 0x0280, + 0x028a, 0x029a, 0x02aa, 0x02ba, 0x02ca, 0x02da, 0x02ea, 0x02fa, 0x030a, + 0x031a, 0x032a, 0x033a, 0x034a, 0x035a, 0x036a, 0x037a, 0x038a, 0x039a, + 0x03aa, 0x03ba, 0x03ca, 0x03da, 0x03ea, 0x03fa, 0x040a, 0x041a, 0x042a, + 0x043a, 0x044a, 0x045a, 0x046a, 0x047a, 0x048a, 0x04be, 0x04f2, 0x0526, + 0x055a, 0x058e, 0x05c2, 0x05f6, 0x062c, 0x0672, 0x06b8, 0x0708, 0x0758, + 0x07a8, 0x07f8, 0x085c, 0x08c0, 0x0924, 0x0988, 0x09ec, 0x0a50, 0x0ab4, + 0x0b18, 0x0b7c, 0x0be0, 0x0c58, 0x0cd0, 0x0d48, 0x0dde, 0x0e74, 0x0f0a, + 0x0fa0, 0x1000}; + + void runLFO(); }; - -