​

// https://github.com/CodingTrain/website/blob/master/CodingChallenges/CC_011_PerlinNoiseTerrain_p5.js/sketch.js

​

// Daniel Shiffman

// http://codingtra.in

// http://patreon.com/codingtrain

// Code for: https://youtu.be/IKB1hWWedMk

// Edited by SacrificeProductions

​

// mod kll & monkstone / oct 2018

​

​

var cols, rows;

var scl = 20;

var w = 1000;

var h = 600;

var x, y;

​

var flying = 0;

var ang = 0,

  speed = 0.07;

​

var terrain = {};

var lake = 0,

  lowlim = -45;

​

var showStroke = false;

​

function setup() {

  createCanvas(700, 600, WEBGL);

  cols = w / scl;

  rows = h / scl;

  ang = PI / 5;

​

  print("cols " + cols + " rows " + rows);

  print("use mouseWheel to change view angle");

  print("click on canvas window first and use: \n [UP] [DOWN] key for water level and [s] for stroke, [f] prints FPS");

}

​

function draw() {

  make_terrain();

​

  background(20, 20, 180);

  if (showStroke)     stroke(200, 200, 0);

  else                noStroke();

  translate(0, 50);

  rotateX(ang);

  translate(-w / 2, -h / 2);

​

  draw_terrain();

}

​

​

function make_terrain() {

  flying -= speed;

  var yoff = flying;

  for (y = 0; y < rows; y++) {

    var xoff = 0;

    for (x = 0; x < cols; x++) {

      terrain[hash_key(x, y)] = constrain(map(noise(xoff, yoff), 0, 1, -100, 100), lowlim, 100);

      xoff += 0.2;

    }

    yoff += 0.2;

  }

}

​

function draw_terrain() {

  for (y = 0; y < rows - 1; y++) {

    beginShape(TRIANGLE_STRIP);

    for (x = 0; x < cols; x++) {

      var one = terrain[hash_key(x, y)];

      var two = terrain[hash_key(x, y + 1)];

      if (one <= lowlim)         lake = 80;

       else                      lake = 0;       // lakes

      fill(50, 150 - int(one), 50 + lake);      // mountain color green to grey

      vertex(x * scl, y * scl, one);

      vertex(x * scl, (y + 1) * scl, two);

    }

    endShape();

  }

}

​

function mouseWheel(event) {

  ang += event.delta / 50.0;

  return false;

}

​

function keyPressed() {

  if (keyCode === UP_ARROW)     print("lowlim: " + (lowlim+=5));

  if (keyCode === DOWN_ARROW)   print("lowlim: " + (lowlim-=5));

  if (key === 's')              print("showStroke: " + (showStroke=!showStroke));        

  if (key === 'f')              print(nf(frameRate(), 0, 1) + " FPS");

}

​

​

function hash_key(x, y) {

  return w * y + x;

}