Angry Birds (Part 5) (SlingShot.js)

 Angry Birds

(Part 5)

SlingShot.js:

class SlingShot {

  constructor(bodyA, pointB) {

    var options = {

      bodyA: bodyA,

      pointB: pointB,

      stiffness: 0.04,

      length: 10,

    };

    this.sling1 = loadImage('sprites/sling1.png');

    this.sling2 = loadImage('sprites/sling2.png');

    this.sling3 = loadImage('sprites/sling3.png');

    this.pointB = pointB;

    this.sling = Constraint.create(options);

    World.add(world, this.sling);

  }

  fly() {

    this.sling.bodyA = null;

  }

  attach(body) {

    this.sling.bodyA = body;

  }

  display() {

    image(this.sling1, 200, 20);

    image(this.sling2, 170, 20);

    if (this.sling.bodyA) {

      var pointA = this.sling.bodyA.position;

      var pointB = this.pointB;

      push();

      stroke(48, 22, 8);

      if (pointA.x < 220) {

        strokeWeight(7);

        line(pointA.x - 20, pointA.y, pointB.x - 10, pointB.y);

        line(pointA.x - 20, pointA.y, pointB.x + 30, pointB.y - 3);

        image(this.sling3, pointA.x - 30, pointA.y - 10, 15, 20);

      } else {

        strokeWeight(3);

        line(pointA.x + 25, pointA.y, pointB.x - 10, pointB.y);

        line(pointA.x + 25, pointA.y, pointB.x + 30, pointB.y - 3);

        image(this.sling3, pointA.x + 25, pointA.y - 10, 15, 20);

      }

      pop();

    }

  }

}