live incoming midi

spoof387

in Contributed Library Questions • 2 years ago

I am trying to make a sketch that visualizes midi data sent from Ableton Live, using the proMidi library. Every midi note is represented by a little ball that moves across the screen. However, I can't seem to write it in a way as to have it deal well with the real-time and potentially infinite nature of the incoming midi data. I've been trying to do this by using ArrayList and adding objects on the fly, but I keep getting an "IndexOutOfBoundsException" error. Any ideas?

My code:

import promidi.*;

MidiIO midiIO;

int notecount = 0;

List<Ball> balls;

void noteOn(
Note note,
int deviceNumber,
int midiChannel
){
pitch = note.getPitch();

notecount = notecount + 1;
}

void setup() {
size(640, 200);
noStroke();
smooth();

midiIO = MidiIO.getInstance(this);
println("printPorts of midiIO");
midiIO.printDevices();
midiIO.openInput(0,0);

balls = new ArrayList();

for (int i = 0; i < notecount; ++i) {
    Ball freshBall = new Ball(width, pitch, 20);
    balls.add(freshBall);
}
}

void draw()
{
background(0);

for (int i = 0; i < notenum; i++) {
Ball ball = (Ball) balls.get(i);
    ball.display();
}
}

class Ball {
float x, y;

Ball(float xin, float yin) {
    x = xin;
    y = yin;
    diameter = din;

}

void display() {
    if (x > -50) {
      x = x - 1;
    }
    fill(255, 204);
    ellipse(x, y, diameter, diameter);
}
}

Replies(2)

PhiLho

Re: live incoming midi

2 years ago

I don't see where the notenum is defined.
Beside, since you use an extensible List, just iterate on the number of items it contents.
I don't see either when you are updating the list with fresh notes.

spoof387

Re: live incoming midi

2 years ago

Thank you for your reply. I'm sorry, but there was indeed a error in the code. I figured 'notecount' would make more sense as a variable name so I changed it from 'notenum' except in that one place. This is the variable that contains the number of iterations that both the for constructions should do, i.e. the number of notes that have been played. Fresh notes are being added in the first for construction where a fresh note is added to the list with 'balls.add(freshBall);'. As for now I've solved part of the problem by moving this for construction from the setup() function to the noteOn() function. However, two problems persist:

1) There seems to be some exponential adding up going on the mentioned for construction. I want each note to and draw a ball on an y coordinate corresponding to its pitch. However, one ball is drawn corresponding to the first note, two to the second note, four to the third note, eight to the fourth note, etc.. I've tried to determine the number of iterations by determining the number of notes in the list using the size() function, but that didn't help either. Any ideas?

2) the ProMIDI noteOn() function seems two return two noteon signals for every note. I figured these would be the note-off messages, but filtering them out using a max for live patch in Ableton didn't help. I'm certain there's only one note on message coming out of the sequencer, but somehow proMIDI takes them as two.

Thanks in advance for any help! Here is my code as it is now:

import promidi.*;

MidiIO midiIO;
List<Ball> balls;

int notecount;
int listsize;

void setup() {
size(640, 200);
noStroke();
smooth();

midiIO = MidiIO.getInstance(this);
println("printPorts of midiIO");
midiIO.printDevices();
midiIO.openInput(0,0);

balls = new ArrayList();
}

void noteOn(
Note note,
int deviceNumber,
int midiChannel
){
int pitch = note.getPitch();
notecount = notecount + 1;
// listsize = balls.size(); <----- here I tried to used the size() function instead of adding 1 to the notecount variable

for (int i = 0; i < notecount; ++i) {
    Ball freshBall = new Ball(width, pitch);
    balls.add(freshBall);
}
}

void note() {

}

void draw() {
background(0);

for (int i = 0; i < notecount; i++) {
    Ball ball = (Ball) balls.get(i);
    ball.display();
    ball.move();
    print ("note-on!") // <--- so I get two of these
}
}

class Ball {
float x, y;

Ball(float xin, float yin) {
    x = xin;
    y = yin;
}

void display() {
    fill(255, 204);
    ellipse(x, y, 20, 20);
}

void move() {
    if (x > -50) {
    x = x - 1;
    }
}
}