Random image array question

Programming Questions

rambo114

in Programming Questions • 9 months ago

Hello!

i have a sketch with images bouncing around the screen. In the original sketch it was balls(ellipse) bouncing around, thats why my sketch have a numBalls variable, and not a numImages variable(i was too lazy to rename),
i can create as many images as i want.
If i create 10 images bouncing around, they will all have the same image, what i want is for them to have a randomly picked image. so that maybe 2 of them have a picture of a basketball, and 3 a golfball and so forth.

In my current code i am trying to make the array pick any of the 5 images i have in the array. What it does is it loops all the images from the array when i hit play. I know it is because i have it in the draw function, so it updates the imagearray all the time. How can i get the array to pick one image, hold on to that image and then choose another one?

The array is in the void display() function. Also this is not the full code, but the rest of it doesn't matter i think.

Thanks for any help :)

import cosm.*;
int numBalls = 100; // Max number of images
float spring = 0.05;
float gravity = 0.03;
float friction = -0.9;
PImage images;
Ball[] balls = new Ball[numBalls];
PImage[] myImageArray = new PImage[5];
void setup() {
size(800, 500);
noStroke();
for (int i = 0; i < numBalls; i++) {
balls[i] = new Ball(random(width), 20, random(30, 70), i, balls);
}
for (int i=0; i<myImageArray.length; i++) {
myImageArray[i] = loadImage( "sopa" + i + ".jpg");
}
}
void draw() {
}
background(0);
for (int i = 0; i < numBalls; i++) {
balls[i].collide();
balls[i].move();
balls[i].display();
}
void display() {
fill(255, 204);
image(myImageArray[(int)random(5)], x, y, diameter, diameter); // Changing the images randomly (not working as it should)
}
}

Replies(5)

bigrichar..

Re: Random image array question

9 months ago

I think it's because you are trying to load an image that doesn't exist, myImageArray has five items, myImageArray[0], myImageArray[1], myImageArray[2], myImageArray[3] and myImageArray[4] however the random command can generate 0,1,2,3,4 and 5 so you are occasionally trying to find myImageArray[5] which doesn't exist.

Either load another image or use:

image(myImageArray[(int)random(0,4)], x, y, diameter, diameter);

rambo114

Re: Random image array question

9 months ago

Hello and thank you for the answer!

I tried your code and the same thing happend :) Maybe i didn't express myself clear enough in the question.

The array loads teh images, thats working.

As you can see here, it loads the images, but it loops them constantly. In the picture they are freezed so it looks like some objects have a black garbagebag and some have a blue one. This is what i am trying to do, but yeah its looping :/
I Know it loops since its in the draw function, but is there anyway it could just assign 1 image to the object and let it keep that image, and then go to the next object and give that one another image(randomly selected).

Thanks!

bigrichar..

Re: Random image array question

9 months ago

Could you do something with an arrayList? This code loads the images (well the filenames) into an arrayList, randomly places one on the screen and then deletes it from the arrayList and picks another one until they are all gone. Maybe you could assign your objects using something like this.

ArrayList images;
String imgFile;
PImage img;
void setup() {
size(400, 600);
images = new ArrayList();
for(int i = 1; i<5; i++) {
    images.add("richard" + i + ".jpg");
}
}

void draw() {
   if (images.size() > 1) {
   int i = (int)random(1,images.size());
   imgFile = (String)images.get(i);
   img = loadImage(imgFile);
   image(img, 0, 0);
   images.remove(i);
   }
}

rambo114

Re: Random image array question

9 months ago

Thank you for your answers :)

Your code works, but what it does is that it selects one of the 5 images when i press run, and then assign that image to all objects. So when i press run a second time the objects will have another images.

void draw() {
if (images.size() > 1) {
int i = (int)random(1,images.size());
imgFile = (String)images.get(i);
img = loadImage(imgFile);
images.remove(i);
}
for (int i = 0; i < numBalls; i++) {
balls[i].collide();
balls[i].move();
balls[i].display();
}
}
void display() {
fill(255, 204);
image(img,x, y,diameter,diameter);
}

I had to use the code like this since the methods display, move and collide are connected so i need to use the image(img,x, y,diameter,diameter); in the display method in order to get it to work. x,y, diameter are variables in the move and collide methods.

Maybe i need an if statement to make some of the objects get one image and some get another one, like if(numBalls == 10) give 4 of the balls image 1 in the array and 2 balls image 2 and so forth.

Do you have any idea how such an if statement can be constructed?(i'm quite new to programming)
Or do you have another solution?

Thanks

rambo114

Re: Random image array question

9 months ago

Ok i solved it, i skipped the imagearray and just manually loaded the images.

Thank you for your help :)

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