Circle packing in Processing

We’ll create a class called Circle

class Circle {
float x;
float y;
float r;

float growRate = 1;
boolean growing = true;

Circle(float x_, float y_){
x = x_;
y = y_;
r = 0.5;
//r = 0.25;
}

void grow(){

if (growing){
r = r+growRate;
}
}

boolean edges(){
return(x+r > width || x-r height ||y-r < 0);
}

void show(){
colrfromImg = clrImg.get(int(x),int(y));//store the color from the image
noStroke();
fill(colrfromImg);
ellipse(x,y,r/2.5,r/2.5);
}
};

We’ll set up our sketch. There are two images being used. One defines the area where the circles will populate, the other image is used to extract a color palette and fill the circles with those colors.

ArrayList circles;
ArrayList spots;

PImage img;
PImage clrImg;
color colrfromImg;
void setup() {
size(1200, 800);
spots = new ArrayList ();
img = loadImage("img42.jpg");
img.loadPixels();
clrImg = loadImage("img31.jpg");
clrImg.loadPixels();
for(int x =0; x<width; x++){
for(int y =0; y<height; y++){ int index = x + y * img.width; color c = img.pixels[index]; float b = brightness(c); if (b > 1){
spots.add(new PVector(x,y));
}
}
}
circles = new ArrayList();
}
void draw() {
background(0);
int total =20;
int count = 0;
int attempts = 0;
while (count < total) { Circle newC = newCircle(); if (newC !=null) { circles.add(newC); count++; } attempts ++; if (attempts > 5000) {
noLoop();//stop completly the program
//println("FINISHED");
break;
}
}
for (Circle c : circles) {
if (c.growing) {
if (c.edges()) {
c.growing = false;
} else {
//boolean overlapping = false;
for (Circle other : circles) {
if (c != other) {
float d = dist(c.x, c.y, other.x, other.y);
if (d < c.r + other.r) {
c.growing = false;
break;
//overlapping = true;
}
}
}
}
}
c.show();
c.grow();
}
}
Circle newCircle() {
int r = int (random(0, spots.size()));
PVector spot = spots.get(r);
float x = spot.x;
float y = spot.y;
boolean valid = true;
for (Circle c : circles) {
float d = dist(x, y, c.x, c.y);
//if (d < c.r + 2 )
if (d < c.r ) {
valid = false;
break;
}
}
if (valid) {
return new Circle (x, y);
} else {
return null;
}
};