perlin noise

_.md

[ Launch: perlin noise ] 5061982 by enjalot

config.json

{"description":"perlin noise","endpoint":"","display":"canvas","public":true,"require":[{"name":"perlin","url":"https://raw.github.com/josephg/noisejs/master/perlin.js"}],"fileconfigs":{"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"_.md":{"default":true,"vim":false,"emacs":false,"fontSize":12},"config.json":{"default":true,"vim":false,"emacs":false,"fontSize":12}},"fullscreen":false,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"period","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01,"thumbnail":"http://i.imgur.com/0R4kCzy.png"}

inlet.js

//playing with noise.js from Joseph Gentle
//https://github.com/josephg/noisejs

var xres = 100;
var yres = 100;
var thresh = 30;
var threshMult = 10;
var alpha = 255;
var scale = 256;

var ctx = tributary.ctx;
var canvas = tributary.canvas;
var image = ctx.createImageData(canvas.width, canvas.height);
var data = image.data;

var start = Date.now();

for (var x = 0; x < canvas.width; x++) {
  //if (x % 100 == 0) {
  //  noise.seed(Math.random());
  //}
  for (var y = 0; y < canvas.height; y++) {
    var value = Math.abs(noise.simplex2(x / xres, y / yres));
    value *= scale;

    var cell = (x + y * canvas.width) * 4;
    data[cell] = data[cell + 1] = data[cell + 2] = value;
    data[cell] += Math.max(0, (thresh - value) * threshMult);
    data[cell + 3] = alpha; // alpha.
  }
}

/* // Benchmark code.
start = Date.now();
for (var x = 0; x < 10000; x++) {
  for (var y = 0; y < 10000; y++) {
    noise.simplex2(x / 50, y/50);
  }
}*/
var end = Date.now();

ctx.fillColor = 'black';
ctx.fillRect(0, 0, 100, 100);
ctx.putImageData(image, 0, 0);


ctx.font = '16px sans-serif'
ctx.textAlign = 'center';
ctx.fillText('Rendered in ' + (end - start) + ' ms', canvas.width / 2, canvas.height - 20);

if(console) {
  console.log('Rendered in ' + (end - start) + ' ms');
}