let world;

let circles = [];

let ground;

​

function setup() {

  createCanvas(800, 600);

​

  engine = Matter.Engine.create();

  world = engine.world;

​

  Matter.Engine.run(engine);

​

  //grund

  ground = Matter.Bodies.rectangle(width / 2, height - 20, width, 40, { isStatic: true });

  Matter.World.add(world, ground);

​

  // Set up collision events

  Matter.Events.on(engine, 'collisionStart', collisionEvent);

  Matter.Events.on(engine, 'collisionEnd', collisionEndEvent);

}

​

function draw() {

  background(220);

​

  circles.forEach(circle => {

    let pos = circle.position;

    let radius = circle.circleRadius;

​

    // Check circle -  collided state

    if (circle.collided) {

      fill(255, 0, 0); // Red if collided

    } else {

      fill(0, 150,0); // Green if not collided

    }

​

    ellipse(pos.x, pos.y, radius * 2);

  });

​

  // Display ground

  fill(100);

  rectMode(CENTER);

  rect(ground.position.x, ground.position.y, width, 40);

}

​

function mouseClicked() {

  let radius = random(10, 50);

  let circle = Matter.Bodies.circle(mouseX, mouseY, radius);

  circle.collided = false; // track collision state

  Matter.World.add(world, circle);

  circles.push(circle);

}

​

​

​

function collisionEvent(event) {

  let pairs = event.pairs;

  for (let i = 0; i < pairs.length; i++) {

    let bodyA = pairs[i].bodyA;

    let bodyB = pairs[i].bodyB;

​

    // Check for collisions involving circles

    if ((circles.includes(bodyA) || circles.includes(bodyB)) && !isGroundCollision(bodyA, bodyB)) {

      circles.forEach(circle => {

        if ((circle === bodyA || circle === bodyB) && circle.collided !== true) {

          circle.collided = true; // true for collisions 

        }

      });

    }

  }

}

​

function isGroundCollision(bodyA, bodyB) {

  return (bodyA === ground || bodyB === ground);

}

​

​

function collisionEndEvent(event) {

  let pairs = event.pairs;

  for (let i = 0; i < pairs.length; i++) {

    let bodyA = pairs[i].bodyA;

    let bodyB = pairs[i].bodyB;

​

    // Find collided bodies and reset their state

    circles.forEach(circle => {

      if (circle === bodyA || circle === bodyB) {

        circle.collided = false; // Reset collided state to false

      }

    });

  }

}

​

​

​