let cam

const unused = 0

​

function half(x) {

  return Math.floor(x / 2)

}

​

function fourth(x) {

  return Math.floor(x / 4)

}

​

function s(x) {

  return x * Math.random() - 0.5

}

​

class Ground {

  constructor(size) {

    this.size = size

    this.elevation = Array(size).fill().map(() => Array(size).fill(unused));

    this.generate(this.elevation, 0, 0, size-1, size-1, 0.3)

  }

  generate(d, x1, y1, x2, y2, rug) {

    //console.log(d)

    const x3 = half(x1 + x2);

    const y3 = half(y1 + y2);

    if (y3 < y2) {

      if (d[x1][y3] == unused) {

        d[x1][y3] = half(d[x1][y1] + d[x1][y2]) + s(rug * (y2 - y1));

      }

      console.log(x2, y3)

      d[x2][y3] = half(d[x2][y1] + d[x2][y2]) + s(rug * (y2 - y1));

    }

    if (x3 < x2) {

      if (d[x3][y1] == unused) {

        d[x3][y1] = half(d[x1][y1] + d[x2][y1]) + s(rug * (x2 - x1));

      }

      d[x3][y2] = half(d[x1][y2] + d[x2][y2]) + s(rug * (x2 - x1));

    }

    if (x3 < x2 && y3 < y2) {

      d[x3][y3] = fourth(d[x1][y1] + d[x2][y1] + d[x1][y2] + d[x2][y2]) +

        s(rug * (Math.abs(x2 - x1) + Math.abs(y2 - y1)));

    }

    if (x3 < x2 - 1 || y3 < y2 - 1) {

      this.generate(d, x1, y1, x3, y3, rug);

      this.generate(d, x1, y3, x3, y2, rug);

      this.generate(d, x3, y1, x2, y3, rug);

      this.generate(d, x3, y3, x2, y2, rug);

    }

  }

  draw() {

    console.log(this.elevation)

    translate(-width/2, 50, 0)

    rotateX(radians(90))

    let g = 10

    for (let row = 0; row < this.size - 1; row += 1) {

      beginShape(TRIANGLE_STRIP)

      for (let col = 0; col < this.size - 1; col += 1) {

        vertex(row * g, col * g, this.elevation[row][col])

        vertex((row + 1) * g, col * g, this.elevation[row + 1][col])

      }

      endShape()

    }

  }

}

​

​

function setup() {

  createCanvas(500, 400, WEBGL)

  // cam = createCamera()

  // cam.camera(0, 100, 300, 0, 0, 0, -1, 0)

  ground = new Ground(40)

  // for (let row = 0; row < 40; row += 1) {

  //   for (let col = 0; col < 40; col += 1) {

  //     ground[row][col] = noise(row*0.03, col*0.03)*150

  //   }

  // }

}

​

function draw() {

  background(220)

  ground.draw()

  // drawGround()

}

​

function drawGround() {

  const g = 10

  push()

  rotateX(1.57)

  translate(-width / 2, -height / 2)

  if (mouseX < width / 2) {

    cam.pan(-0.001)

  } else if (mouseX > width / 2) {

    cam.pan(0.001)

  }

  if (mouseY < height / 2) {

    cam.tilt(0.001)

  } else if (mouseY > height / 2) {

    cam.tilt(-0.001)

  }

  cam.move(0, 0, -0.5)

  pop()

}