Ball.js

function Ball(position, color){
    this.position = position;
    this.velocity = new Vector2();
    this.moving = false;
    this.sprite = getBallSpriteByColor(color);
    this.color = color;
    this.visible = true;
}

Ball.prototype.update = function(delta){

    if(!this.visible){
        return;
    }

    this.position.addTo(this.velocity.mult(delta));

    // Apply friction
    this.velocity = this.velocity.mult(1 - CONSTANTS.frictionEnergyLoss);

    if(this.velocity.length() < CONSTANTS.minVelocityLength){
        this.velocity = new Vector2();
        this.moving = false;
    }
}

Ball.prototype.draw = function(){
    
    if(!this.visible){
        return;
    }

    Canvas.drawImage(this.sprite, this.position, CONSTANTS.ballOrigin);
}

Ball.prototype.shoot = function(power, rotation){

    this.velocity = new Vector2(power * Math.cos(rotation), power * Math.sin(rotation));
    this.moving = true;
}

Ball.prototype.collideWithBall = function(ball){

    if(!this.visible || !ball.visible){
        return;
    }

    // Find a normal vector
    const n = this.position.subtract(ball.position);

    // Find distance
    const dist = n.length();

    if(dist > CONSTANTS.ballDiameter){
        return;
    }

    // Find minimum translation distance
    const mtd = n.mult((CONSTANTS.ballDiameter - dist) / dist);

    // Push-pull balls apart
    this.position = this.position.add(mtd.mult(1/2));
    ball.position = ball.position.subtract(mtd.mult(1/2));

    // Find unit normal vector
    const un = n.mult(1/n.length());

    // Find unit tangent vector
    const ut = new Vector2(-un.y, un.x);

    // Project velocities onto the unit normal and unit tangent vectors
    const v1n = un.dot(this.velocity);
    const v1t = ut.dot(this.velocity);
    const v2n = un.dot(ball.velocity);
    const v2t = ut.dot(ball.velocity);

    // Find new normal velocities
    let v1nTag = v2n;
    let v2nTag = v1n;

    // Convert the scalar normal and tangential velocities into vectors
    v1nTag = un.mult(v1nTag);
    const v1tTag = ut.mult(v1t);
    v2nTag = un.mult(v2nTag);
    const v2tTag = ut.mult(v2t);

    // Update velocities
    this.velocity = v1nTag.add(v1tTag);
    ball.velocity = v2nTag.add(v2tTag);

    this.moving = true;
    ball.moving = true;

}

Ball.prototype.handleBallInPocket = function(){

    if(!this.visible){
        return;
    }

    let inPocket = CONSTANTS.pockets.some(pocket => {
        return this.position.distFrom(pocket) < CONSTANTS.pocketRadius;
    });

    if(!inPocket){
        return;
    }

    this.visible = false;
    this.moving = false;
}

Ball.prototype.collideWithTable = function(table){

    if(!this.moving || !this.visible){
        return;
    }

    let collided = false;

    if(this.position.y <= table.TopY + CONSTANTS.ballRadius){
        this.position.y = table.TopY + CONSTANTS.ballRadius;
        this.velocity = new Vector2(this.velocity.x, -this.velocity.y);
        collided = true;
    }

    if(this.position.x >= table.RightX - CONSTANTS.ballRadius){
        this.position.x = table.RightX - CONSTANTS.ballRadius;
        this.velocity = new Vector2(-this.velocity.x, this.velocity.y);
        collided = true;
    }

    if(this.position.y >= table.BottomY - CONSTANTS.ballRadius){
        this.position.y = table.BottomY - CONSTANTS.ballRadius;
        this.velocity = new Vector2(this.velocity.x, -this.velocity.y);
        collided = true;
    }

    if(this.position.x <= table.LeftX + CONSTANTS.ballRadius){
        this.position.x = table.LeftX + CONSTANTS.ballRadius;
        this.velocity = new Vector2(-this.velocity.x, this.velocity.y);
        collided = true;
    }

    if(collided){
        this.velocity = this.velocity.mult(1 - CONSTANTS.collisionEnergyLoss);
    }

}