Bouncy Bubbles
/**
* Bouncy Bubbles
* based on code from Keith Peters.
*
* Multiple-object collision.
*/
class Ball;
int numBalls = 12;
float spring = 0.05;
float gravity = 0.03;
float friction = -0.9;
ArrayList<Ball> balls;
class Ball {
public:
float x, y;
float diameter;
float vx = 0;
float vy = 0;
int id;
ArrayList<Ball>* others;
Ball(float xin, float yin, float din, int idin, ArrayList<Ball>* oin) {
x = xin;
y = yin;
diameter = din;
id = idin;
others = oin;
}
void collide() {
for (int i = id + 1; i < numBalls; i++) {
Ball* other = others->get(i);
float dx = other->x - x;
float dy = other->y - y;
float distance = sqrt(dx*dx + dy*dy);
float minDist = other->diameter/2 + diameter/2;
if (distance < minDist) {
float angle = atan2(dy, dx);
float targetX = x + cos(angle) * minDist;
float targetY = y + sin(angle) * minDist;
float ax = (targetX - other->x) * spring;
float ay = (targetY - other->y) * spring;
vx -= ax;
vy -= ay;
other->vx += ax;
other->vy += ay;
}
}
}
void move() {
vy += gravity;
x += vx;
y += vy;
if (x + diameter/2 > width) {
x = width - diameter/2;
vx *= friction;
}
else if (x - diameter/2 < 0) {
x = diameter/2;
vx *= friction;
}
if (y + diameter/2 > height) {
y = height - diameter/2;
vy *= friction;
}
else if (y - diameter/2 < 0) {
y = diameter/2;
vy *= friction;
}
}
void display() {
ellipse(x, y, diameter, diameter);
}
};
void setup() {
size(640, 360);
for (int i = 0; i < numBalls; i++) balls.add(nullptr); // pre-size, like Java's "new Ball[numBalls]"
for (int i = 0; i < numBalls; i++) {
balls[i] = new Ball(random(width), random(height), random(30, 70), i, &balls);
}
noStroke();
fill(255, 204);
}
void draw() {
background(0);
for (Ball* ball : balls) {
ball->collide();
ball->move();
ball->display();
}
}