let ray;

let particle;

​

const sceneW = 700;

const sceneH = 700;

let sliderFOV;

​

function setup() {

  createCanvas(700, 1400);

  for (let i = 0; i < 6; i++) {

    let x1 = random(sceneW);

    let x2 = random(sceneW);

    let y1 = random(sceneH);

    let y2 = random(sceneH);

    let r = random(255);

    let g = random(255);

    let b = random(255);

    walls[i] = new Boundary(x1, y1, x2, y2, r, g, b);

  }

  walls.push(new Boundary(0, 0, sceneW, 0, 255, 255, 255));

  walls.push(new Boundary(sceneW, 0, sceneW, sceneH, 255, 255, 255));

  walls.push(new Boundary(sceneW, sceneH, 0, sceneH, 255, 255, 255));

  walls.push(new Boundary(0, sceneH, 0, 0, 255, 255, 255));

  particle = new Particle();

  sliderFOV = createSlider(0, 120, 90);

  sliderFOV.input(changeFOV);

  sliderFOV.position(10, 10);

}

​

function changeFOV() {

  const fov = sliderFOV.value();

  particle.updateFOV(fov);

}

​

function draw() {

  if (keyIsDown(LEFT_ARROW)) {

    particle.rotate(-0.01);

  } else if (keyIsDown(RIGHT_ARROW)) {

    particle.rotate(0.01);

  } else if (keyIsDown(UP_ARROW)) {

    particle.move(1);

  } else if (keyIsDown(DOWN_ARROW)) {

    particle.move(-1);

  }

​

  background(0);

  for (let wall of walls) {

    wall.show();

  }

  particle.show();

​

  const scene = particle.look(walls);

  const sliceWidth = sceneW / scene.length;

  push();

  for (let i = 0; i < scene.length; i++) {

    noStroke();

    // Calculate how far away the wall is relative to whole scene

    // We can look as far as the sceneW * sceneH (which is a square in this case)

    // (inverse square law)

    const sq = scene[i][0] * scene[i][0];

    const wSq = sceneW * sceneH;

    const brightness = map(sq, 0, wSq, 255, 0);

    const sliceHeight = map(scene[i][0], 0, sceneW, sceneH, 0);

    // Add the view

    col = scene[i][1].levels;

    fill(col[0] * (brightness / 255), col[1] * (brightness / 255), col[2] * (brightness / 255));

    rectMode(CENTER);

    rect(i * sliceWidth, sceneH * (3/2), sliceWidth + 1, sliceHeight);

  }

  pop();

}