/**
 * Part of Picozu Image Editing application.
 * Visit https://www.picozu.com for more info.
 * The code is copyrighted by Picozu <www.picozu.com>.
 * 
 * @version 1.1.121413
 * @package Workers
 * @application Picozu <www.picozu.com>
 * @license www.picozu.com/license
 */

importScripts('quantize.js');

self.addEventListener('message', function(e) {
    function process(data) {
        data.params.numcolors = (typeof data.params.numcolors != 'undefined') ? data.params.numcolors : 29;
        return {
            colors: loadSwatches(data.imageData, data.params.numcolors)
        };
    }
    self.postMessage(process(e.data));
}, false);

function loadSwatches(image, colorCount) {
    var pixels = image.data;
    var pixelCount = image.width * image.height;
    var pixelArray = [];
    for (var i = 0, offset, r, g, b, a; i < pixelCount; i++) {
        offset = i * 4;
        r = pixels[offset + 0];
        g = pixels[offset + 1];
        b = pixels[offset + 2];
        a = pixels[offset + 3];
        if (a >= 125) {
            if (!(r > 250 && g > 250 && b > 250)) {
                pixelArray.push([r, g, b]);
            }
        }
    }
    var cmap = MMCQ.quantize(pixelArray, colorCount);
    if (cmap) {
        var palette = cmap.palette();
        return palette;
    }
    else {
        return null;
    }
}