Mapping midicontroller to color variable

rhklein

Mapping midicontroller to color variable

in Contributed Library Questions • 1 year ago

Hi,
I read some older thread about mapping midiinput to variables in the forums and decided to try it myself, since i have a "korg nanoKontrol".

I want to controll the RGB values of a stroke with 3 different controllers on the "nanoKontrol".
Here is what i got so far:

import themidibus.*;
MidiBus myBus;

void setup() {
myBus = new MidiBus(this, 0, 2);
size(200, 200);
}

void draw() {
}

void controllerChange(int channel, int number, int value) {
int R = value*2;
int G = value*2;
int B = value*2;

if (mousePressed==true) {
stroke(R, G, B);
line(mouseX, mouseY, pmouseX, pmouseY);
}
}

I know the stroke() function belongs into the draw() function, because otherwise i can only draw while I change the controller.
I tried putting it in draw(), but then I can't access the value variable inside controllerChange().

How do I assign each RGB value a different channel number and its corresponding value? (So changing the first controller on the nanoKontrol will result in changing only the R value)

R= controllerChange(0, 2, int valueR)
G=controllerChange(0, 3, int valueG)
B=controllerChange(0, 4, int valueB)

Thanks!

rhklein

Replies(2)

Jonny Stu..

Re: Mapping midicontroller to color variable

1 year ago

You don't want to do your drawing in controllerChange(). One option would be to set stroke() inside controllerChange() and do your drawing in draw() but I think it's better to make R, G and B global and keep stroke() near line():

import themidibus.*;
MidiBus myBus;
int R = 0, G = 0, B = 0;
void setup() {
myBus = new MidiBus(this, 0, 2);
size(200, 200);
}
void draw() {
if (mousePressed==true) {
stroke(R, G, B);
line(mouseX, mouseY, pmouseX, pmouseY);
}
}
void controllerChange(int channel, int number, int value) {
R = value*2;
G = value*2;
B = value*2;
}

rhklein

Re: Mapping midicontroller to color variable

1 year ago

Thank you Jonny. It works.
I typed out an elaborate answer, but accidentally deleted it, while trying to edit...

Here is the final code

import themidibus.*;

MidiBus myBus;
int R = 0, G = 0, B = 0;
float brushsize = 0;

void setup() {
myBus = new MidiBus(this, 0, 2);
size(300, 300);
background(255);
}

void draw() {
if (mousePressed==true) {
    strokeWeight(brushsize);
    stroke(R, G, B);
    line(mouseX, mouseY, pmouseX, pmouseY);
}
}

void controllerChange(int channel, int number, int value) {

if (number==2) {
    R = value*2;
}
if (number==3) {
    G = value*2;
}
if (number==4) {
    B = value*2;
}
if (number==5) {
    brushsize=value*0.5;
}
}

//edit i wonder, why it doesn't make a new line in the code box if I copy and paste the code?

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