/*

Simple wave table VCO.

Author: Leonardo Laguna Ruiz - leonardo@vult-dsp.com

Check the API documentation in the basic.vult example

*/

fun pitchToFreq(cv) @[table(size=128, min=-10.0, max=10.0)] {
   return 261.6256 * exp(cv * 0.69314718056);
}

// Generates (at compile time) a wave table based on the provided harmonics
// To change the wave table, change the 'harmonics' array
fun wavetable(phase) @[table(size=128, min=0.0, max=1.0)] {
   val harmonics = [0.0, 1.0, 0.7, 0.5, 0.3];
   val n = size(harmonics);
   val acc = 0.0;
   val i = 0;
   while(i < n) {
      acc = acc + harmonics[i] * sin(2.0 * pi() * real(i) * phase);
      i = i + 1;
   }
   return acc / sqrt(real(n));
}

fun process(input_cv:real) {
   mem phase;
   val knob_cv = getKnob(1) - 0.5;
   val cv = 10.0 * (input_cv + knob_cv);
   val freq = pitchToFreq(cv);
   val delta = sampletime() * freq;
   phase = phase + delta;
   if(phase > 1.0) {
      phase = phase - 1.0;
   }

   return wavetable(phase);
}
and update() {

}