Array Index Out Of Bounds

Programming Questions

jjulien

in Programming Questions • 2 years ago

Hi,

I'm new in Processing and i got a problem i can't find the answer :

ArrayIndexOutOfBundsException : 0

The idea of my project is to randomly display points of construction of a font each time you click, anyway i'll put you an image of what i'd like in result and my code :

As i said i'm really new so maybe there is error of construction, please tell me !

THANKS !

import geomerative.*;

cercle [] touslescercle;

RFont font;

String textTyped = "TEST";

boolean doSave = false;

float a;

float b;

void setup() {

size(1324,350);

frame.setResizable(true);

smooth();

RG.init(this);

font = new RFont("FreeSans.ttf", 200, RFont.LEFT);

RCommand.setSegmentLength (11);

RCommand.setSegmentator(RCommand.UNIFORMLENGTH);

touslescercle = new cercle [0];

}

void draw() {

background(255);

translate(20,220);

if (textTyped.length() > 0) {

RGroup grp;

grp = font.toGroup(textTyped);

grp = grp.toPolygonGroup();

RPoint[] pnts = grp.getPoints();

// dots

fill(0);

noStroke();

for (int i = 0; i < pnts.length; i++ ) {

touslescercle[i].dessine();

float a = random(pnts[i].x);

float b = random(pnts[i].y);

}

class cercle {

float diametre,x,y;

cercle() {

x = a;

y = b;

diametre = 7;

touslescercle = (cercle[]) append

(touslescercle, this);

}

void dessine(){

ellipse(x, y, diametre, diametre);

}

void mouseReleased(){

new cercle();

}

Replies(2)

eerriicc

You're initializing the array touslescercle with a size of 0 - which means there's can't be any elements in there.

Later, you access the elements in touslescercle depending on the number of RPoints, which is probably bigger than 0. So you're trying to access the first element of an empty array, which results in this Exception.

I think you should initialize the array in draw() like this:

RPoint[] pnts = grp.getPoints();
touslescercle = new cercle [pnts.length];

Best regards,
Eric

PhiLho

Re: Array Index Out Of Bounds

2 years ago

touslescercle = new cercle [0];

A size of zero means the array is empty, any attempt to get something out of it will result in the exception you mention.
Moreover, you loop on the length of a (seemingly) unrelated array and access to items on another array. You should loop on touslescercle.length instead, that would avoid to access non-existing entries.
Notes:
- float a and b in the loop seems unused.
- the way to add cercles to the array is... unusual. In general, we create a new instance, get its reference and add it to a collection. An ArrayList is more suited for that.
Something like:

ArrayList<cercle> touslescercles = new ArrayList<cercle>(); // I prefer to use plural for collections and arrays
void mouseReleased(){
cercle c = new cercle();
touslescercles.add(c);
}
// Loop can be:
for (cercle c : touslescercles) {
c.dessine();
}