peacock/plugin/voiceboard.hpp

/*
   Peacock-8 VA polysynth

   Copyright 2024 Gordon JC Pearce <gordonjcp@gjcp.net>

   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.
*/

#pragma once

#include <cstdint>

#define NUM_VOICES 8
class LFO {
   public:
    LFO();
    void run();
    int16_t lfoOut;
    uint8_t rate;

   private:
    uint8_t
        phase;
    uint16_t holdoff;
    uint16_t envelope;
    enum { LFO_RUN,
           LFO_HOLDOFF,
           LFO_RAMP } delayPhase;
    static const uint16_t lfoRateTable[128];
};

class Envelope {
   public:
    Envelope();

    void run();
    void on() {
        phase = ENV_ATK;
    }

    void off() {
        phase = ENV_RLS;
    }

    bool inRelease() {
        return phase == ENV_RLS;
    }

    static uint16_t atk, dcy, stn, rls;

    uint16_t level;

   private:
    static const uint16_t atkTable[128];
    static const uint16_t dcyTable[128];

    enum {
        ENV_ATK,
        ENV_DCY,
        ENV_RLS,
        ENV_IDLE
    } phase;
};

class Voice {
   public:
    Voice();
    uint8_t note = 0x3c;  // middle C
    void run(float *buffer, uint32_t pos, uint32_t samples);
    void filter(float *buffer, uint32_t pos, uint32_t samples);

    void update();
    void on(uint8_t note);
    void off();

    // private:
    Envelope env;             // calculated envelope value
    uint16_t pitch = 0x1818;  // calculated pitch value with porta and master pitch etc
    float delay = 0;          // delay slot for polyblep
    bool pulseStage = 0;
    float pw = 0, lastpw = 0, pwrc = 0;
    float subosc = -1;
    float sub = 0, saw = 0;
    float phase = 0, omega = 0;
    enum { V_DONE,
           V_OFF,
           V_ON } voiceState;

    void calcPitch();

    float fb = 0, b1 = 0, b2 = 0, b3 = 0, b4 = 0, cut = 0.1, reso = 4;
};

class Synth {
    friend Envelope;
    friend Voice;

   public:
    Synth();
    void run();
    void voiceOn(uint8_t voice, uint8_t note);
    void voiceOff(uint8_t voice);
    void sustainSwitch(uint8_t val);
    void buildTables(double sampleRate);

    double sampleRate;
    uint32_t bufferSize;
    uint16_t masterPitch;  // sum of bend and LFO, plus any other pitch-setting value
                           // protected:
    uint16_t envAtk, envDcy, envStn, envRls;
    int8_t portaCoeff;
    bool sustained;
    double pitchTable[104];
    double filterTable[256];

    float *noise;

    // private:
    uint8_t vcoBend = 42;
    uint8_t vcfBend = 42;

    Voice voices[NUM_VOICES];
    LFO lfo;
    uint16_t pitchBend = 0x2000;
    uint8_t modWheel = 0x00;

    float pwm;
    uint32_t tr21;

    struct {
        uint8_t lfoRate = 0x3f;
        uint8_t lfoDelay = 0x00;
        uint8_t vcoLfoMod = 0x00;
        uint8_t pwmLfoMod = 0x27;
        uint8_t noiseLevel = 0x00;
        uint8_t vcfCutoff = 0x4d;
        uint8_t vcfReso = 0x14;
        uint8_t vcfEnvMod = 0x04;
        uint8_t vcfLfoMod = 0x00;
        uint8_t vcfKeyTrk = 0x6f;
        uint8_t vcaLevel = 0x22;
        uint8_t attack = 0x0d;
        uint8_t decay = 0x57;
        uint8_t sustain = 0x58;
        uint8_t release = 0x23;
        uint8_t subLevel = 0x0e;
        uint8_t switch1 = 0x1a;
        uint8_t switch2 = 0x10;
    } patchRam;
    const static uint16_t lfoDelayTable[8];
    const static uint8_t lfoDepthTable[128];
    const static uint8_t portaTable[128];
};