let fov = sliderFOV.value();

  particle.updateFOV(fov);

}

​

function intersectLineCircle(p1, p2, cpt, r) {

    let x1 = p1.copy().sub(cpt);

    let x2 = p2.copy().sub(cpt);

    let dv = x2.copy().sub(x1)

    let dr = dv.mag();

    let D = x1.x*x2.y - x2.x*x1.y;

​

    let di = r*r*dr*dr - D*D;

    if (di < 0.0){

        return false;

    }else{

      return true;

    }

}

​

class Particle{

  constructor(){

    this.fov = 60;

    this.rez = 1;

    this.pos = createVector(10,10);

    this.rays = [];

    this.heading = 0;

    this.step = this.fov * da;

    for (let a = -this.fov / 2; a < this.fov / 2; a += this.step) {

      this.rays.push(new Ray(this.pos, radians(a) + this.heading, radians(a)));

    }

  }

  updateFOV(fov) {

    this.fov = fov;

    this.rays = [];

    for (let a = -this.fov / 2; a < this.fov / 2; a += this.step) {

      this.rays.push(new Ray(this.pos, radians(a) + this.heading, radians(a)));

    }

  }

​

  rotate(angle) {

    this.heading += angle;

    let index = 0;

    for (let a = -this.fov / 2; a < this.fov / 2; a += this.step) {

      this.rays[index].setAngle(radians(a) + this.heading, radians(a));

      index++;

    }

  }

  move(m){

    let gate = true;

    for(let wall of walls){

      if(intersectLineCircle(wall.a,wall.b,this.pos,1)){

        gate = false;

      }else{

        gate = true;

      }

    }

    if(gate){

      var vel = p5.Vector.fromAngle(this.heading);

      vel.setMag(m);

      this.pos.add(vel);

    }

  }

  update(x,y){

    this.pos.set(x,y);

  }

  look(walls,dr){

    var scene = [];

    var index = 0;

    for(let ray of this.rays){

      let closest = null;

      let record = Infinity;

      let cWall = null;

      for(let wall of walls){

        const pt = ray.cast(wall);

        if(pt){

          let d = p5.Vector.dist(this.pos,pt);

          if(d < record){

            record = d;

            closest = pt;

            cWall = wall;

          }

        }

      }

      if(closest){

        cWall.seenByPlayer();

        if(dr && (index == (this.fov/this.step)/2 || index == 0 || index == this.rays.length-1)){

          stroke(255,0,0,80);

          line(this.pos.x,this.pos.y,closest.x,closest.y);

        }

      }

      scene.push(record * cos(ray.angleFromCenter));

      index++;

    }

    return scene; 

  }

  show() {

    fill(60);

    ellipse(this.pos.x,this.pos.y,16);

  }

}