chassis/plugin/chassis.cpp

/*
   Chassis polysynth framework

   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"

START_NAMESPACE_DISTRHO

Chassis::Chassis() : Plugin(parameterCount, 0, 0), sampleRate(getSampleRate()) {  // one parameter, no programs, no states
}

// Initialisation functions

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";
}

// Processing functions

void Chassis::activate() {
    // calculate filter coefficients and stuff
    printf("called activate()\n");

    for (uint8_t i=0; i<104; i++) {
        s.pitchCV[i] = (261.63 * powf(2, (i-24) / 12.0f)) / sampleRate;
    }
}

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

void Chassis::noteOn(uint8_t note) {
    uint32_t i;
    s.keyon = true;
    for (i = 0; i < NUM_VOICES; i++) {
        vPtr++;
        if (vPtr == NUM_VOICES) vPtr = 0;
        if (s.voice[vPtr].isFree()) {
            // printf("voice %d is free, existing note = %d, note = %d\n", vPtr, s.voice[i].note, note);
            //  if it's an existing note don't reset
            s.voice[vPtr].on(note, s.voice[i].note != note);
            // printf("note on %d for voice %d\n", note, vPtr);
            break;
        }
    }

    if (i == NUM_VOICES) {  // didn't find a free voice
        vPtr++;
        if (vPtr == NUM_VOICES) vPtr = 0;
        s.voice[vPtr].on(note, true);
    }
}

void Chassis::noteOff(uint8_t note) {
    // printf("noteoff %d\n", note);
    s.keyon = false;
    for (uint32_t i = 0; i < NUM_VOICES; i++) {
        if (s.voice[i].note == note && !s.voice[i].isFree()) {
            s.voice[i].off();
            // printf("note off %d for voice %d\n", note, i);
            break;
        }
    }
}

void Chassis::doMidi(const MidiEvent *ev, uint32_t count, uint32_t timeLimit) {
    // printf("doMidi() handling events from %d to %d\n", lastEvent, timeLimit);
    uint32_t i;
    if (count == 0) return;
    for (i = lastEvent; i < count; i++) {
        // printf("doMidi event number %d of %d %02x %02x\n", i, count, ev[i].data[0], ev[i].data[1]);
        if (ev[i].frame > timeLimit) break;
        switch (ev[i].data[0]) {
            case 0x90:
                noteOn(ev[i].data[1]);
                break;
            case 0x80:
                noteOff(ev[i].data[1]);
                break;
        }
    }
    lastEvent = i;
}

void Chassis::run(const float **, float **outputs, uint32_t frames, const MidiEvent *midiEvents, uint32_t midiEventCount) {
    // if (midiEventCount > 0) printf("\n--------------------\n");

    uint32_t framePos = 0;
    uint32_t sizeThisTime;
    s.framesLeft = frames;

    // printf("\n------------\ncalled run() for %d frames\n",frames);

    // flatten the left channel to use as temporary storage, since
    // the synth engine only generates a mono channel
    bzero(outputs[0], sizeof(float) * frames);

    // get any of the last block's worth of MIDI out of the way
    lastEvent = 0;
    doMidi(midiEvents, midiEventCount, s.blockLeft);

    while (framePos < frames) {
        if (s.blockLeft == 0) {
            s.blockLeft = sampleRate / 238;
            doMidi(midiEvents, midiEventCount, framePos + s.blockLeft);

            // printf("compute params and reset block size\n");
            s.lfoDelay();
            s.runLFO();

            for (uint32_t i = 0; i < NUM_VOICES; i++) {
                s.voice[i].calcPitch(s);

                    switch(s.patchRam.switch1 & 0x03) {
        case 1: s.voice[i].omega /= 4; break;
        case 2: s.voice[i].omega /= 2;
        default: break;
    }

                //printf("voice %d note = %02x ff71 = %04x\n",i, s.voice[i].note, s.voice[i].ff71 );
                s.voice[i].gate(s);
            }
        }

        sizeThisTime = (s.framesLeft < s.blockLeft) ? s.framesLeft : s.blockLeft;

        // printf("sL = %d bL = %d, calculating %d frames at %d\n", s.framesLeft, s.blockLeft, sizeThisTime, framePos);

        // run each synth voice

        for (uint8_t i = 0; i < NUM_VOICES; i++) {
            s.voice[i].run(s, outputs[0] + framePos, sizeThisTime);
        }

        framePos += sizeThisTime;
        s.framesLeft -= sizeThisTime;
        s.blockLeft -= sizeThisTime;
    }
    // printf("and now run the rest of the process for %d frames\n\n", frames);

    // copy left to right
    memmove(outputs[1], outputs[0], sizeof(float) * frames);
    // outputs[1][1]=1;
}

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

END_NAMESPACE_DISTRHO