constructor(sc) {

    this.sc = sc;

    this.thresh = 1e-7;

    this.pos = createVector(1, 0, 0);

    if (abs(this.pos.mag() - 1.0) > this.thresh) {

      throw ("position vector no bueno.");

    }

    this.ori = createVector(0, 0, -1);

  }

​

  moveForw(stepSize) {

    this.pos = this.RotAroundU(this.pos, this.ori, stepSize)

  }

​

  moveBack(stepSize) {

    this.pos = this.RotAroundU(this.pos, this.ori.copy().mult(-1), stepSize)

  }

​

  show() {

    push();

    translate(width / 2, height / 2);

    translate(this.sc * this.pos.x, this.sc * this.pos.y);

    fill(0, 255, 0);

    noStroke();

    ellipse(0, 0, 10*(1-this.pos.z), 10*(1-this.pos.z));

    pop();

  }

​

  rotLeft(stepSize) {

    this.ori = this.RotAroundU(this.ori, this.pos, stepSize);

  }

​

  rotRight(stepSize) {

    this.ori = this.RotAroundU(this.ori, this.pos, -stepSize);

  }

​

  flip() {

    this.ori.mult(-1);

  }

​

  RotAroundU(yin, u, theta) {

    let y = [yin.x, yin.y, yin.z];

    let R = [

      [cos(theta) + u.x * u.x * (1 - cos(theta)), u.x * u.y * (1 - cos(theta)) - u.z * sin(theta), u.x * u.z * (1 - cos(theta)) + u.y * sin(theta)],

      [u.x * u.y * (1 - cos(theta)) + u.z * sin(theta), cos(theta) + u.y * u.y * (1 - cos(theta)), u.y * u.z * (1 - cos(theta)) - u.x * sin(theta)],

      [u.x * u.z * (1 - cos(theta)) - u.y * sin(theta), u.y * u.z * (1 - cos(theta)) + u.x * sin(theta), cos(theta) + u.z * u.z * (1 - cos(theta))]

    ];

    let z = [];

    for (let mi = 0; mi < 3; mi++) {

      let tmp = 0;

      for (let ni = 0; ni < 3; ni++) {

        tmp += R[mi][ni] * y[ni];

      }

      z.push(tmp);

    }

    return createVector(z[0], z[1], z[2]);

  }

  rayMarch(fov,objects) {

    let d = objects[0].signedDistanceToObject(this.pos);

    text(d.toFixed(3),width-100,20);

  }

}