​

let engine;       

let particles = []; // (lava pieces)

let volcano;       

let ground;        

​

​

function setup() {

    createCanvas(800, 600); 

    engine = Engine.create(); 

​

    // creates a triangular body to represent the volcano

    volcano = Bodies.polygon(400, height - 50, 3, 100, { isStatic: true });

    // creates a rectangular body to represent the ground

    ground = Bodies.rectangle(400, height, 800, 40, { isStatic: true });

​

    // add the volcano and ground to the physics world

    World.add(engine.world, [volcano, ground]);

​

    // sets up a collision event listener for the start of collisions

    Events.on(engine, 'collisionStart', function(event) {

        event.pairs.forEach(pair => {

  // to get the two bodies involved in each collision pair

            const { bodyA, bodyB } = pair;

// Changes the color of the bodies if they are particles

            if (bodyA.render && bodyA.circleRadius) bodyA.render.fillStyle = color(random(255), random(255), random(255));

            if (bodyB.render && bodyB.circleRadius) bodyB.render.fillStyle = color(random(255), random(255), random(255));

        });

    });

}

​

function draw() {

    background(51); 

    Engine.update(engine); // updates the physics engine

​

​

    fill(150, 75, 0); // color for volcano

    push(); 

    translate(volcano.position.x, volcano.position.y); 

​

    rotate(volcano.angle); 

    triangle(-50, 50, 0, -50, 50, 50); // triangle for volcano

    pop(); 

​

    fill(127); 

    rectMode(CENTER);

    rect(ground.position.x, ground.position.y, 800, 40); 

​

    // drawing the particles

    particles.forEach(part => {

        fill(part.render.fillStyle || [255, 0, 0]); // sets the color of each particle, initializing the color to red to represent lava

        ellipse(part.position.x, part.position.y, 10, 10); // shape of each particle

    });

}

​

​

function mousePressed() {

    erupt(); // calls the erupt function 

}

​

function erupt() {

    let particle = Bodies.circle(400, height - 150, 5, { restitution: 0.8 });

    particle.render.fillStyle = color(255, 0, 0); // initializes the particle color to red

​

    Body.setVelocity(particle, { x: random(-5, 5), y: random(-10, -15) });

    particles.push(particle); // adds the particle to the array

    World.add(engine.world, particle); // adds the particle to the physics world

​

    // removes old particles for efficiency

    if (particles.length > 200) {

        let oldParticle = particles.shift(); // removes oldest particle from the array

        World.remove(engine.world, oldParticle); // removes oldest particle from the physics world

    }

}

​

function applyWind() {

    let windForce = 0.0005; // Strength of the wind force

    particles.forEach(particle => {

        Body.applyForce(particle, { x: particle.position.x, y: particle.position.y }, { x: windForce, y: 0 });

    });

}

​

​

function keyPressed() {

    if (keyCode === 32) { // keycode for space

        applyWind();

    }

}