HEADER.js

/*! Fabric.js Copyright 2008-2015, Printio (Juriy Zaytsev, Maxim Chernyak) */

var fabric = fabric || { version: '3.4.0' };
if (typeof exports !== 'undefined') {
  exports.fabric = fabric;
}
/* _AMD_START_ */
else if (typeof define === 'function' && define.amd) {
  define([], function() { return fabric; });
}
/* _AMD_END_ */
if (typeof document !== 'undefined' && typeof window !== 'undefined') {
  if (document instanceof (typeof HTMLDocument !== 'undefined' ? HTMLDocument : Document)) {
    fabric.document = document;
  }
  else {
    fabric.document = document.implementation.createHTMLDocument('');
  }
  fabric.window = window;
}
else {
  // assume we're running under node.js when document/window are not present
  var jsdom = require('jsdom');
  var virtualWindow = new jsdom.JSDOM(
    decodeURIComponent('%3C!DOCTYPE%20html%3E%3Chtml%3E%3Chead%3E%3C%2Fhead%3E%3Cbody%3E%3C%2Fbody%3E%3C%2Fhtml%3E'),
    {
      features: {
        FetchExternalResources: ['img']
      },
      resources: 'usable'
    }).window;
  fabric.document = virtualWindow.document;
  fabric.jsdomImplForWrapper = require('jsdom/lib/jsdom/living/generated/utils').implForWrapper;
  fabric.nodeCanvas = require('jsdom/lib/jsdom/utils').Canvas;
  fabric.window = virtualWindow;
  DOMParser = fabric.window.DOMParser;
}

/**
 * True when in environment that supports touch events
 * @type boolean
 */
fabric.isTouchSupported = 'ontouchstart' in fabric.window || 'ontouchstart' in fabric.document ||
  (fabric.window && fabric.window.navigator && fabric.window.navigator.maxTouchPoints > 0);

/**
 * True when in environment that's probably Node.js
 * @type boolean
 */
fabric.isLikelyNode = typeof Buffer !== 'undefined' &&
                      typeof window === 'undefined';

/* _FROM_SVG_START_ */
/**
 * Attributes parsed from all SVG elements
 * @type array
 */
fabric.SHARED_ATTRIBUTES = [
  'display',
  'transform',
  'fill', 'fill-opacity', 'fill-rule',
  'opacity',
  'stroke', 'stroke-dasharray', 'stroke-linecap', 'stroke-dashoffset',
  'stroke-linejoin', 'stroke-miterlimit',
  'stroke-opacity', 'stroke-width',
  'id', 'paint-order', 'vector-effect',
  'instantiated_by_use', 'clip-path'
];
/* _FROM_SVG_END_ */

/**
 * Pixel per Inch as a default value set to 96. Can be changed for more realistic conversion.
 */
fabric.DPI = 96;
fabric.reNum = '(?:[-+]?(?:\\d+|\\d*\\.\\d+)(?:[eE][-+]?\\d+)?)';
fabric.fontPaths = { };
fabric.iMatrix = [1, 0, 0, 1, 0, 0];

/**
 * Pixel limit for cache canvases. 1Mpx , 4Mpx should be fine.
 * @since 1.7.14
 * @type Number
 * @default
 */
fabric.perfLimitSizeTotal = 2097152;

/**
 * Pixel limit for cache canvases width or height. IE fixes the maximum at 5000
 * @since 1.7.14
 * @type Number
 * @default
 */
fabric.maxCacheSideLimit = 4096;

/**
 * Lowest pixel limit for cache canvases, set at 256PX
 * @since 1.7.14
 * @type Number
 * @default
 */
fabric.minCacheSideLimit = 256;

/**
 * Cache Object for widths of chars in text rendering.
 */
fabric.charWidthsCache = { };

/**
 * if webgl is enabled and available, textureSize will determine the size
 * of the canvas backend
 * @since 2.0.0
 * @type Number
 * @default
 */
fabric.textureSize = 2048;

/**
 * When 'true', style information is not retained when copy/pasting text, making
 * pasted text use destination style.
 * Defaults to 'false'.
 * @type Boolean
 * @default
 */
fabric.disableStyleCopyPaste = false;

/**
 * Enable webgl for filtering picture is available
 * A filtering backend will be initialized, this will both take memory and
 * time since a default 2048x2048 canvas will be created for the gl context
 * @since 2.0.0
 * @type Boolean
 * @default
 */
fabric.enableGLFiltering = true;

/**
 * Device Pixel Ratio
 * @see https://developer.apple.com/library/safari/documentation/AudioVideo/Conceptual/HTML-canvas-guide/SettingUptheCanvas/SettingUptheCanvas.html
 */
fabric.devicePixelRatio = fabric.window.devicePixelRatio ||
                          fabric.window.webkitDevicePixelRatio ||
                          fabric.window.mozDevicePixelRatio ||
                          1;
/**
 * Browser-specific constant to adjust CanvasRenderingContext2D.shadowBlur value,
 * which is unitless and not rendered equally across browsers.
 *
 * Values that work quite well (as of October 2017) are:
 * - Chrome: 1.5
 * - Edge: 1.75
 * - Firefox: 0.9
 * - Safari: 0.95
 *
 * @since 2.0.0
 * @type Number
 * @default 1
 */
fabric.browserShadowBlurConstant = 1;

/**
 * This object contains the result of arc to beizer conversion for faster retrieving if the same arc needs to be converted again.
 * It was an internal variable, is accessible since version 2.3.4
 */
fabric.arcToSegmentsCache = { };

/**
 * This object keeps the results of the boundsOfCurve calculation mapped by the joined arguments necessary to calculate it.
 * It does speed up calculation, if you parse and add always the same paths, but in case of heavy usage of freedrawing
 * you do not get any speed benefit and you get a big object in memory.
 * The object was a private variable before, while now is appended to the lib so that you have access to it and you
 * can eventually clear it.
 * It was an internal variable, is accessible since version 2.3.4
 */
fabric.boundsOfCurveCache = { };

/**
 * If disabled boundsOfCurveCache is not used. For apps that make heavy usage of pencil drawing probably disabling it is better
 * @default true
 */
fabric.cachesBoundsOfCurve = true;

/**
 * Skip performance testing of setupGLContext and force the use of putImageData that seems to be the one that works best on
 * Chrome + old hardware. if your users are experiencing empty images after filtering you may try to force this to true
 * this has to be set before instantiating the filtering backend ( before filtering the first image )
 * @type Boolean
 * @default false
 */
fabric.forceGLPutImageData = false;

fabric.initFilterBackend = function() {
  if (fabric.enableGLFiltering && fabric.isWebglSupported && fabric.isWebglSupported(fabric.textureSize)) {
    console.log('max texture size: ' + fabric.maxTextureSize);
    return (new fabric.WebglFilterBackend({ tileSize: fabric.textureSize }));
  }
  else if (fabric.Canvas2dFilterBackend) {
    return (new fabric.Canvas2dFilterBackend());
  }
};