konva/src/filters/Solarize.js

<p align="center"> <img src="https://raw.githubusercontent.com/konvajs/konvajs.github.io/master/apple-touch-icon-180x180.png" alt="Konva logo" height="180" /> </p>

(function() {
  'use strict';
  /**
     * Solarize Filter
     * Pixastic Lib - Solarize filter - v0.1.0
     * Copyright (c) 2008 Jacob Seidelin, jseidelin@nihilogic.dk, http://blog.nihilogic.dk/
     * License: [http://www.pixastic.com/lib/license.txt]
     * @function
     * @name Solarize
     * @memberof Konva.Filters
     * @param {Object} imageData
     * @example
     * node.cache();
     * node.filters([Konva.Filters.Solarize]);
     */
  Konva.Filters.Solarize = function(imageData) {
    var data = imageData.data,
      w = imageData.width,
      h = imageData.height,
      w4 = w * 4,
      y = h;

    do {
      var offsetY = (y - 1) * w4;
      var x = w;
      do {
        var offset = offsetY + (x - 1) * 4;
        var r = data[offset];
        var g = data[offset + 1];
        var b = data[offset + 2];

        if (r > 127) {
          r = 255 - r;
        }
        if (g > 127) {
          g = 255 - g;
        }
        if (b > 127) {
          b = 255 - b;
        }

        data[offset] = r;
        data[offset + 1] = g;
        data[offset + 2] = b;
      } while (--x);
    } while (--y);
  };
})();