var applyCubeLUT = require('apply-cube-lut');
var parseCubeLUT = require('parse-cube-lut');
var ndarrayFromImage  = require('ndarray-from-image');
var canvasFromNdarray = require('canvas-from-ndarray');
var ops = require('ndarray-ops');

var lutURL = 'test.cube';
var imgURL = 'test.jpg';

var req = new XMLHttpRequest();
var img = new Image();

req.onload = function() {
  img.onload = function() {

    // once both the image and LUT data are loaded
    var lut = parseCubeLUT(req.responseText);
    var arr = ndarrayFromImage(img, 'float32');

    // convert RGBA components to 0.0 -> 1.0
    ops.mulseq(arr, 1.0 / 255.0);

    // apply LUT
    applyCubeLUT(arr /* dest */, arr /* src */, lut);

    // convert back to 0.0 -> 255.0
    ops.mulseq(arr, 255.0);

    // display transformed image
    var canvas = canvasFromNdarray(arr);
    document.body.appendChild(canvas);
  };
  
  img.src = imgURL;
};

req.open('GET', lutURL, true);
req.send();