chassis/plugin/chassis.cpp

/*
   Chassis reverb plugin

   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.
*/

#include "chassis.hpp"

SVF::SVF(float cutoff = 0, float q = 0, float samplerate = 0) {
    z1 = z2 = 0;
    setFreq(cutoff, q, samplerate);
}

void SVF::setFreq(float cutoff, float q, float samplerate) {
    z1 = z2 = 0;

    printf("called with %f %f %f\n", cutoff, q, samplerate);
    w = 2 * tan(3.14159 * (cutoff / samplerate));
    a = w / q;
    b = w * w;

    // corrected SVF params, per Fons Adriaensen
    c1 = (a + b) / (1 + a / 2 + b / 4);
    c2 = b / (a + b);

    d0 = c1 * c2 / 4;

    printf("c1 %f c2 %f d0 %f\n", c1, c2, d0);
}

inline float SVF::lpStep(float in) {
    x = in - z1 - z2;
    z2 += c2 * z1;
    z1 += c1 * x;
    return d0 * x + z2;
}

START_NAMESPACE_DISTRHO

Chassis::Chassis() : Plugin(kParameterCount, 0, 0) {  // one parameter, no programs, no states
    // lowpass = new float[getBufferSize()];
    // ram = new int16_t[16384];

    // bzero(lowpass, sizeof(float) * getBufferSize());
    // bzero(ram, sizeof(int16_t) * 16384);

    // f1.setFreq(5916, .6572, getSampleRate());
    // f2.setFreq(9458, 2.536, getSampleRate());
}

// Initialisation functions

void Chassis::initParameter(uint32_t index, Parameter &parameter) {
    if (index == p_saw) {
        parameter.hints = kParameterIsAutomatable | kParameterIsInteger;
        parameter.name = "Saw";
        parameter.symbol = "saw";
        parameter.ranges.max = 1.0f;
    }
    if (index == p_sqr) {
        parameter.hints = kParameterIsAutomatable | kParameterIsInteger;
        parameter.name = "Square";
        parameter.symbol = "sqr";
        parameter.ranges.max = 4.0f;
    }

    if (index == p_sublev) {
        parameter.hints = kParameterIsAutomatable;
        parameter.name = "Sub";
        parameter.symbol = "sub";
        parameter.ranges.def = 20.0f;
        parameter.ranges.min = 1.0f;
        parameter.ranges.max = 64.0f;
    }
    if (index == paramProgram) {
        parameter.hints = kParameterIsAutomatable;
        parameter.name = "prog";
        parameter.symbol = "prog";
        parameter.ranges.def = 1.0f;
        parameter.ranges.min = 0.0f;
        parameter.ranges.max = 1.0f;
    }
}

void Chassis::setParameterValue(uint32_t index, float value) {
}

float Chassis::getParameterValue(uint32_t index) const {
    return 0;
}

void Chassis::initAudioPort(bool input, uint32_t index, AudioPort &port) {
    port.groupId = kPortGroupStereo;
    Plugin::initAudioPort(input, index, port);

    if (!input && index == 0) port.name = "Left Out";
    if (!input && index == 1) port.name = "Right Out";
}
/*
void Chassis::initProgramName(uint32_t index, String &programName) {
    programName = "init";
}

void Chassis::loadProgram(uint32_t index) {
    prog_offset = (index & 0x3f) << 7;
    program = index + 1;
}
*/
// Processing functions

void Chassis::activate() {
    // calculate filter coefficients
    printf("called activate()\n");
    for (uint32_t i = 0; i< NUM_VOICES; i++ ) {
        assign[i] = 0x80 | i; 
        
    }
}

void Chassis::deactivate() {
    // zero out the outputs, maybe
    printf("called deactivate()\n");
    printf("%02x", assign[1]);
}

void Chassis::noteOn(uint8_t note) {
    for (uint32_t i = 0; i < NUM_VOICES; i++) {
        printf("note on, finding free voice in %02x for %d\n", assign[i], note);
        if (assign[i] & 0x80) {  // top bit is voice free flag
            assign[i] &= 0x7f;   // enable
            printf("voice %d would be set to note %d\n", assign[i], note);
            break;
        }

        if (i == NUM_VOICES) {  // didn't find a free voice
            uint32_t v = assign[0];
            memmove(assign, assign + 1, NUM_VOICES - 1);  // shunt all voices down by one
            assign[NUM_VOICES - 1] = v;                   // oldest voice goes at the top of the queue
            printf("no free voices, reused %d for note %d\n", v, note);
        }
    }
    printf("note table is now ");
    for (uint32_t i=0; i < NUM_VOICES; i++ ) {
        printf("%02x = ", assign[i]);
    }
    printf("----------------------------\n");

}

/*
void Chassis::noteOff(uint8_t note) {

    uint32_t v;
    printf("note off called for %3d\n", note);

    for (uint32_t i = 0; i < NUM_VOICES; i++) {
        v = assign[i];
        printf("trying voice %02x\n", v);
        if (v < 0x80) {
            printf("note %02x is playing\n", v);
        
        }

    }

}
*/
void Chassis::run(const float **, float **outputs, uint32_t frames, const MidiEvent *MidiEvents, uint32_t midiEventCount) {
    if (midiEventCount > 0) printf("\n--------------------\n");
    for (uint32_t i = 0; i < midiEventCount; i++) {
        printf("%4d %02x %02x\n", MidiEvents[i].frame, MidiEvents[i].data[0], MidiEvents[i].data[1]);
        if (MidiEvents[i].data[0] == 0x90) {
            noteOn(MidiEvents[i].data[1]);
        }
    }
}

// create the plugin
Plugin *createPlugin() { return new Chassis(); }

END_NAMESPACE_DISTRHO