processing_MIDI/midi_gh.pde

import themidibus.*;

MidiBus myBus;
ArrayList<PVector> squares;
ArrayList<Integer> velocities;
color[] pitchColors;

void setup() {
  size(400, 400);
  squares = new ArrayList<PVector>();
  velocities = new ArrayList<Integer>();
  MidiBus.list();
  myBus = new MidiBus(this, 2, 3);
  
  pitchColors = new color[128];
  for (int pitch = 0; pitch < 128; pitch++) {
    if (pitch == 36){
      pitchColors[pitch] = color(255, 255, 255);
    }
    if (pitch == 38){
      pitchColors[pitch] = color(255, 0, 0);
    }
    if (pitch == 48){
      pitchColors[pitch] = color(0, 0, 255);
    }
    if (pitch == 45){
      pitchColors[pitch] = color(0, 255, 0);
    }
    if (pitch == 46){
      pitchColors[pitch] = color(205, 85, 0);
    }
    if (pitch == 49){
      pitchColors[pitch] = color(255, 255, 0);
    }
  }
} 

void draw() {
  background(0);
  
  for (int i = 0; i < squares.size(); i++) {
    PVector square = squares.get(i);
    int pitch = (int) square.z;
    int velocity = velocities.get(i);
    fill(pitchColors[pitch]);
    rect(square.x, square.y, velocity, velocity);
  }
}

void noteOn(int channel, int pitch, int velocity) {
  println("--------");
  println("Channel: "+channel, "Pitch: "+pitch, "Velocity: "+velocity);
  if (pitch == 36 || pitch == 38 || pitch == 48 || pitch == 45 || pitch == 46 || pitch == 49) {
    squares.add(new PVector(random(width), random(height), pitch));
    velocities.add(velocity);
  }
}

void noteOff(int channel, int pitch, int velocity) {
  println("--------");
  println("Channel: "+channel, "Pitch: "+pitch, "Velocity: "+velocity);
  if (pitch == 36 || pitch == 38 || pitch == 48 || pitch == 45 || pitch == 46 || pitch == 49) {
    for (int i = squares.size() - 1; i >= 0; i--) {
      if (squares.get(i).z == pitch) {
        squares.remove(i);
        velocities.remove(i);
      }
    }
  }
}

void controllerChange(int channel, int number, int value) {
  println("--------");
  println("Channel: "+channel, "Number: "+number, "Value: "+value);
}