let terrainSize = 800;

let terrainResolution = 40;

let terrain;

let mountainSize = 100;

let mountainHeight = 300;

​

function setup() {

  createCanvas(800, 600, WEBGL);

  plane = new Plane();

  terrain = generateTerrain();

}

​

function draw() {

  background(0);

  // Handle user input

  handleInput();

​

  // Update the plane's position and orientation

  plane.update();

  // Set up camera

  camera(0, -200, 400, 0, 0, 0, 0, 1, 0);

  // Draw the terrain

  drawTerrain();

  // Draw the plane

  plane.display();

}

​

function handleInput() {

  // Rotate left

  if (keyIsDown(LEFT_ARROW)) {

    plane.rotateY(-0.02);

  }

​

  // Rotate right

  if (keyIsDown(RIGHT_ARROW)) {

    plane.rotateY(0.02);

  }

​

  // Pitch up

  if (keyIsDown(UP_ARROW)) {

    plane.rotateX(-0.02);

  }

​

  // Pitch down

  if (keyIsDown(DOWN_ARROW)) {

    plane.rotateX(0.02);

  }

​

  // Yaw left

  if (keyIsDown(65)) { // 'A' key

    plane.rotateZ(0.02);

  }

​

  // Yaw right

  if (keyIsDown(68)) { // 'D' key

    plane.rotateZ(-0.02);

  }

​

  // Move forward

  if (keyIsDown(87)) { // 'W' key

    plane.move(0.1);

  }

​

  // Move backward

  if (keyIsDown(83)) { // 'S' key

    plane.move(-0.1);

  }

}

​

function generateTerrain() {

  let terrain = [];

  let halfSize = terrainSize / 2;

  let stepSize = terrainSize / terrainResolution;

  for (let x = -halfSize; x < halfSize; x += stepSize) {

    for (let y = -halfSize; y < halfSize; y += stepSize) {

      let z = noise(x * 0.01, y * 0.01) * mountainHeight;

      terrain.push(createVector(x, y, z));

    }

  }

  return terrain;

}

​

function drawTerrain() {

  noStroke();

  // Draw terrain

  fill(50, 200, 50);

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

    let vertex = terrain[i];

    push();

    translate(vertex.x, vertex.y, vertex.z);

    box(terrainResolution, terrainResolution, 2);

    pop();

  }

  // Draw mountain

  fill(150, 75, 0);

  let mountainX = map(plane.position.x, -terrainSize / 2, terrainSize / 2, -mountainSize / 2, mountainSize / 2);

  let mountainY = map(plane.position.y, -terrainSize / 2, terrainSize / 2, -mountainSize / 2, mountainSize / 2);

  let mountainZ = map(plane.position.z, -terrainSize / 2, terrainSize / 2, 0, mountainHeight);

  push();

  translate(mountainX, mountainY, mountainZ);

  box(mountainSize, mountainSize, mountainHeight);

  pop();

}

​

class Plane {

  constructor() {

    this.position = createVector(0, 0, 0);

    this.rotation = createVector(0, 0, 0);

  }

​

  update() {

    this.position.add(this.rotation);

  }

​

  display() {

    push();

    translate(this.position.x, this.position.y, this.position.z);

    rotateX(this.rotation.x);

    rotateY(this.rotation.y);

    rotateZ(this.rotation.z);

    fill(255);

    noStroke();

    box(40, 20, 100);

    pop();

  }

​

  rotateX(angle) {

    this.rotation.x += angle;

  }

​

  rotateY(angle) {

    this.rotation.y += angle;

  }

​

  rotateZ(angle) {

    this.rotation.z += angle;

  }

​

  move(speed) {

    let direction = p5.Vector.fromAngles(this.rotation.y, this.rotation.x);

    direction.normalize();

    direction.mult(speed);

    this.position.add(direction);

  }

}

​