PicoWaveTracker/SequenceGenerator.cpp

#include "SequenceGenerator.h"
#include "SharedState.h"
#include "MidiDriver.h"
#include <Arduino.h>

void SequenceGenerator::getChordNotes(int* chordNotes, int& numChordNotes) {
    numChordNotes = 0;
    if (numScaleNotes == 0) return;

    // For explicit chord types, chord notes are the scale notes
    if (currentScaleType >= 6 && currentScaleType <= 9) {
        numChordNotes = numScaleNotes;
        for (int i = 0; i < numScaleNotes; i++) {
            chordNotes[i] = scaleNotes[i];
        }
        return;
    }

    // For other scales, derive the basic triad (root, third, fifth) from the current scale
    chordNotes[numChordNotes++] = currentRoot;

    // Find the third (major or minor)
    int majorThird = (currentRoot + 4) % 12;
    int minorThird = (currentRoot + 3) % 12;
    bool thirdFound = false;
    for (int i = 0; i < numScaleNotes; i++) {
        if (scaleNotes[i] == majorThird) {
            chordNotes[numChordNotes++] = majorThird;
            thirdFound = true;
            break;
        }
    }
    if (!thirdFound) {
        for (int i = 0; i < numScaleNotes; i++) {
            if (scaleNotes[i] == minorThird) {
                chordNotes[numChordNotes++] = minorThird;
                break;
            }
        }
    }

    // Find the fifth (perfect, or diminished if not found)
    int perfectFifth = (currentRoot + 7) % 12;
    int diminishedFifth = (currentRoot + 6) % 12;
    for (int i = 0; i < numScaleNotes; i++) {
        if (scaleNotes[i] == perfectFifth) {
            chordNotes[numChordNotes++] = perfectFifth;
            return;
        }
    }
    for (int i = 0; i < numScaleNotes; i++) {
        if (scaleNotes[i] == diminishedFifth) {
            chordNotes[numChordNotes++] = diminishedFifth;
            break;
        }
    }
}

void SequenceGenerator::generateTrackData(int track, int themeType, Step (*target)[NUM_STEPS]) {
    randomSeed(melodySeeds[track] + themeType * 12345);
    int chordNotes[12];
    int numChordNotes = 0;
    getChordNotes(chordNotes, numChordNotes);
    strategies[currentStrategyIndices[track]]->generate(target, track, numSteps[track], scaleNotes, numScaleNotes, chordNotes, numChordNotes, melodySeeds[track] + themeType * 12345, trackIntensity[track]);
}

void SequenceGenerator::generateRandomScale() {
  Serial.println(F("Generating new scale."));
  SequenceGenerator::updateScale();
}

void SequenceGenerator::updateScale() {
    // 0: Chromatic, 1: Major, 2: Minor, 3: Harm Min, 4: Pent Maj, 5: Pent Min, 6: Chord Maj, 7: Chord Min, 8: Chord Dim, 9: Chord 7
    int intervals[12];
    int count = 0;
    
    switch(currentScaleType) {
        case 0: // Chromatic
            for(int i=0; i<12; i++) intervals[count++] = i;
            break;
        case 1: // Major
            intervals[0]=0; intervals[1]=2; intervals[2]=4; intervals[3]=5; intervals[4]=7; intervals[5]=9; intervals[6]=11; count=7;
            break;
        case 2: // Minor
            intervals[0]=0; intervals[1]=2; intervals[2]=3; intervals[3]=5; intervals[4]=7; intervals[5]=8; intervals[6]=10; count=7;
            break;
        case 3: // Harmonic Minor
            intervals[0]=0; intervals[1]=2; intervals[2]=3; intervals[3]=5; intervals[4]=7; intervals[5]=8; intervals[6]=11; count=7;
            break;
        case 4: // Pentatonic Major
            intervals[0]=0; intervals[1]=2; intervals[2]=4; intervals[3]=7; intervals[4]=9; count=5;
            break;
        case 5: // Pentatonic Minor
            intervals[0]=0; intervals[1]=3; intervals[2]=5; intervals[3]=7; intervals[4]=10; count=5;
            break;
        case 6: // Chord Major
            intervals[0]=0; intervals[1]=4; intervals[2]=7; count=3;
            break;
        case 7: // Chord Minor
            intervals[0]=0; intervals[1]=3; intervals[2]=7; count=3;
            break;
        case 8: // Chord Dim
            intervals[0]=0; intervals[1]=3; intervals[2]=6; count=3;
            break;
        case 9: // Chord 7
            intervals[0]=0; intervals[1]=4; intervals[2]=7; intervals[3]=10; count=4;
            break;
    }
    
    midi.lock();
    numScaleNotes = count;
    for(int i=0; i<count; i++) {
        scaleNotes[i] = (currentRoot + intervals[i]) % 12;
    }
    sortArray(scaleNotes, numScaleNotes);
    midi.unlock();
}

void SequenceGenerator::generateSequenceData(int themeType, Step (*target)[NUM_STEPS]) {
  Serial.println(F("Generating sequence."));
  for(int i=0; i<NUM_TRACKS; i++) {
    SequenceGenerator::generateTrackData(i, themeType, target);
  }
}

void SequenceGenerator::mutateSequence(Step (*target)[NUM_STEPS]) {
  int chordNotes[12];
  int numChordNotes = 0;
  getChordNotes(chordNotes, numChordNotes);
  for(int i=0; i<NUM_TRACKS; i++) {
    if (random(100) < (trackIntensity[i] * 10)) {
      strategies[currentStrategyIndices[i]]->mutate(target, i, numSteps[i], scaleNotes, numScaleNotes, chordNotes, numChordNotes, trackIntensity[i]);
    }
  }
}

void SequenceGenerator::pickRandomScaleType(int themeType) {
    unsigned long seed = themeType * 9999;
    for(int i=0; i<NUM_TRACKS; i++) seed += melodySeeds[i];
    randomSeed(seed);

    currentScaleType = random(10);
    SequenceGenerator::updateScale();
}