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(Created page with "<html> <script language="JavaScript"> // Copyright 2006 Google Inc. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except i...")
 
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<html>
 
<script language="JavaScript">
<script language="JavaScript">
// Copyright 2006 Google Inc.
// Copyright 2006 Google Inc.

Revision as of 17:06, 25 March 2015

<script language="JavaScript"> // Copyright 2006 Google Inc. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License.

// Modifications by Graham Breach ( http://www.goat1000.com/ ) // - apply globalAlpha in drawImage

// Known Issues: // // * Patterns only support repeat. // * Radial gradient are not implemented. The VML version of these look very // different from the canvas one. // * Clipping paths are not implemented. // * Coordsize. The width and height attribute have higher priority than the // width and height style values which isn't correct. // * Painting mode isn't implemented. // * Canvas width/height should is using content-box by default. IE in // Quirks mode will draw the canvas using border-box. Either change your // doctype to HTML5 // (http://www.whatwg.org/specs/web-apps/current-work/#the-doctype) // or use Box Sizing Behavior from WebFX // (http://webfx.eae.net/dhtml/boxsizing/boxsizing.html) // * Non uniform scaling does not correctly scale strokes. // * Optimize. There is always room for speed improvements.

// Only add this code if we do not already have a canvas implementation if (!document.createElement('canvas').getContext) {

(function() {

 // alias some functions to make (compiled) code shorter
 var m = Math;
 var mr = m.round;
 var ms = m.sin;
 var mc = m.cos;
 var abs = m.abs;
 var sqrt = m.sqrt;
 // this is used for sub pixel precision
 var Z = 10;
 var Z2 = Z / 2;
 var IE_VERSION = +navigator.userAgent.match(/MSIE ([\d.]+)?/)[1];
 /**
  * This funtion is assigned to the <canvas> elements as element.getContext().
  * @this {HTMLElement}
  * @return {CanvasRenderingContext2D_}
  */
 function getContext() {
   return this.context_ ||
       (this.context_ = new CanvasRenderingContext2D_(this));
 }
 var slice = Array.prototype.slice;
 /**
  * Binds a function to an object. The returned function will always use the
  * passed in {@code obj} as {@code this}.
  *
  * Example:
  *
  *   g = bind(f, obj, a, b)
  *   g(c, d) // will do f.call(obj, a, b, c, d)
  *
  * @param {Function} f The function to bind the object to
  * @param {Object} obj The object that should act as this when the function
  *     is called
  * @param {*} var_args Rest arguments that will be used as the initial
  *     arguments when the function is called
  * @return {Function} A new function that has bound this
  */
 function bind(f, obj, var_args) {
   var a = slice.call(arguments, 2);
   return function() {
     return f.apply(obj, a.concat(slice.call(arguments)));
   };
 }
 function encodeHtmlAttribute(s) {
   return String(s).replace(/&/g, '&').replace(/"/g, '"');
 }
 function addNamespace(doc, prefix, urn) {
   if (!doc.namespaces[prefix]) {
     doc.namespaces.add(prefix, urn, '#default#VML');
   }
 }
 function addNamespacesAndStylesheet(doc) {
   addNamespace(doc, 'g_vml_', 'urn:schemas-microsoft-com:vml');
   addNamespace(doc, 'g_o_', 'urn:schemas-microsoft-com:office:office');
   // Setup default CSS.  Only add one style sheet per document
   if (!doc.styleSheets['ex_canvas_']) {
     var ss = doc.createStyleSheet();
     ss.owningElement.id = 'ex_canvas_';
     ss.cssText = 'canvas{display:inline-block;overflow:hidden;' +
         // default size is 300x150 in Gecko and Opera
         'text-align:left;width:300px;height:150px}';
   }
 }
 // Add namespaces and stylesheet at startup.
 addNamespacesAndStylesheet(document);
 var G_vmlCanvasManager_ = {
   init: function(opt_doc) {
     var doc = opt_doc || document;
     // Create a dummy element so that IE will allow canvas elements to be
     // recognized.
     doc.createElement('canvas');
     doc.attachEvent('onreadystatechange', bind(this.init_, this, doc));
   },
   init_: function(doc) {
     // find all canvas elements
     var els = doc.getElementsByTagName('canvas');
     for (var i = 0; i < els.length; i++) {
       this.initElement(els[i]);
     }
   },
   /**
    * Public initializes a canvas element so that it can be used as canvas
    * element from now on. This is called automatically before the page is
    * loaded but if you are creating elements using createElement you need to
    * make sure this is called on the element.
    * @param {HTMLElement} el The canvas element to initialize.
    * @return {HTMLElement} the element that was created.
    */
   initElement: function(el) {
     if (!el.getContext) {
       el.getContext = getContext;
       // Add namespaces and stylesheet to document of the element.
       addNamespacesAndStylesheet(el.ownerDocument);
       // Remove fallback content. There is no way to hide text nodes so we
       // just remove all childNodes. We could hide all elements and remove
       // text nodes but who really cares about the fallback content.
       el.innerHTML = ;
       // do not use inline function because that will leak memory
       el.attachEvent('onpropertychange', onPropertyChange);
       el.attachEvent('onresize', onResize);
       var attrs = el.attributes;
       if (attrs.width && attrs.width.specified) {
         // TODO: use runtimeStyle and coordsize
         // el.getContext().setWidth_(attrs.width.nodeValue);
         el.style.width = attrs.width.nodeValue + 'px';
       } else {
         el.width = el.clientWidth;
       }
       if (attrs.height && attrs.height.specified) {
         // TODO: use runtimeStyle and coordsize
         // el.getContext().setHeight_(attrs.height.nodeValue);
         el.style.height = attrs.height.nodeValue + 'px';
       } else {
         el.height = el.clientHeight;
       }
       //el.getContext().setCoordsize_()
     }
     return el;
   }
 };
 function onPropertyChange(e) {
   var el = e.srcElement;
   switch (e.propertyName) {
     case 'width':
       el.getContext().clearRect();
       el.style.width = el.attributes.width.nodeValue + 'px';
       // In IE8 this does not trigger onresize.
       el.firstChild.style.width =  el.clientWidth + 'px';
       break;
     case 'height':
       el.getContext().clearRect();
       el.style.height = el.attributes.height.nodeValue + 'px';
       el.firstChild.style.height = el.clientHeight + 'px';
       break;
   }
 }
 function onResize(e) {
   var el = e.srcElement;
   if (el.firstChild) {
     el.firstChild.style.width =  el.clientWidth + 'px';
     el.firstChild.style.height = el.clientHeight + 'px';
   }
 }
 G_vmlCanvasManager_.init();
 // precompute "00" to "FF"
 var decToHex = [];
 for (var i = 0; i < 16; i++) {
   for (var j = 0; j < 16; j++) {
     decToHex[i * 16 + j] = i.toString(16) + j.toString(16);
   }
 }
 function createMatrixIdentity() {
   return [
     [1, 0, 0],
     [0, 1, 0],
     [0, 0, 1]
   ];
 }
 function matrixMultiply(m1, m2) {
   var result = createMatrixIdentity();
   for (var x = 0; x < 3; x++) {
     for (var y = 0; y < 3; y++) {
       var sum = 0;
       for (var z = 0; z < 3; z++) {
         sum += m1[x][z] * m2[z][y];
       }
       result[x][y] = sum;
     }
   }
   return result;
 }
 function copyState(o1, o2) {
   o2.fillStyle     = o1.fillStyle;
   o2.lineCap       = o1.lineCap;
   o2.lineJoin      = o1.lineJoin;
   o2.lineWidth     = o1.lineWidth;
   o2.miterLimit    = o1.miterLimit;
   o2.shadowBlur    = o1.shadowBlur;
   o2.shadowColor   = o1.shadowColor;
   o2.shadowOffsetX = o1.shadowOffsetX;
   o2.shadowOffsetY = o1.shadowOffsetY;
   o2.strokeStyle   = o1.strokeStyle;
   o2.globalAlpha   = o1.globalAlpha;
   o2.font          = o1.font;
   o2.textAlign     = o1.textAlign;
   o2.textBaseline  = o1.textBaseline;
   o2.arcScaleX_    = o1.arcScaleX_;
   o2.arcScaleY_    = o1.arcScaleY_;
   o2.lineScale_    = o1.lineScale_;
 }
 var colorData = {
   aliceblue: '#F0F8FF',
   antiquewhite: '#FAEBD7',
   aquamarine: '#7FFFD4',
   azure: '#F0FFFF',
   beige: '#F5F5DC',
   bisque: '#FFE4C4',
   black: '#000000',
   blanchedalmond: '#FFEBCD',
   blueviolet: '#8A2BE2',
   brown: '#A52A2A',
   burlywood: '#DEB887',
   cadetblue: '#5F9EA0',
   chartreuse: '#7FFF00',
   chocolate: '#D2691E',
   coral: '#FF7F50',
   cornflowerblue: '#6495ED',
   cornsilk: '#FFF8DC',
   crimson: '#DC143C',
   cyan: '#00FFFF',
   darkblue: '#00008B',
   darkcyan: '#008B8B',
   darkgoldenrod: '#B8860B',
   darkgray: '#A9A9A9',
   darkgreen: '#006400',
   darkgrey: '#A9A9A9',
   darkkhaki: '#BDB76B',
   darkmagenta: '#8B008B',
   darkolivegreen: '#556B2F',
   darkorange: '#FF8C00',
   darkorchid: '#9932CC',
   darkred: '#8B0000',
   darksalmon: '#E9967A',
   darkseagreen: '#8FBC8F',
   darkslateblue: '#483D8B',
   darkslategray: '#2F4F4F',
   darkslategrey: '#2F4F4F',
   darkturquoise: '#00CED1',
   darkviolet: '#9400D3',
   deeppink: '#FF1493',
   deepskyblue: '#00BFFF',
   dimgray: '#696969',
   dimgrey: '#696969',
   dodgerblue: '#1E90FF',
   firebrick: '#B22222',
   floralwhite: '#FFFAF0',
   forestgreen: '#228B22',
   gainsboro: '#DCDCDC',
   ghostwhite: '#F8F8FF',
   gold: '#FFD700',
   goldenrod: '#DAA520',
   grey: '#808080',
   greenyellow: '#ADFF2F',
   honeydew: '#F0FFF0',
   hotpink: '#FF69B4',
   indianred: '#CD5C5C',
   indigo: '#4B0082',
   ivory: '#FFFFF0',
   khaki: '#F0E68C',
   lavender: '#E6E6FA',
   lavenderblush: '#FFF0F5',
   lawngreen: '#7CFC00',
   lemonchiffon: '#FFFACD',
   lightblue: '#ADD8E6',
   lightcoral: '#F08080',
   lightcyan: '#E0FFFF',
   lightgoldenrodyellow: '#FAFAD2',
   lightgreen: '#90EE90',
   lightgrey: '#D3D3D3',
   lightpink: '#FFB6C1',
   lightsalmon: '#FFA07A',
   lightseagreen: '#20B2AA',
   lightskyblue: '#87CEFA',
   lightslategray: '#778899',
   lightslategrey: '#778899',
   lightsteelblue: '#B0C4DE',
   lightyellow: '#FFFFE0',
   limegreen: '#32CD32',
   linen: '#FAF0E6',
   magenta: '#FF00FF',
   mediumaquamarine: '#66CDAA',
   mediumblue: '#0000CD',
   mediumorchid: '#BA55D3',
   mediumpurple: '#9370DB',
   mediumseagreen: '#3CB371',
   mediumslateblue: '#7B68EE',
   mediumspringgreen: '#00FA9A',
   mediumturquoise: '#48D1CC',
   mediumvioletred: '#C71585',
   midnightblue: '#191970',
   mintcream: '#F5FFFA',
   mistyrose: '#FFE4E1',
   moccasin: '#FFE4B5',
   navajowhite: '#FFDEAD',
   oldlace: '#FDF5E6',
   olivedrab: '#6B8E23',
   orange: '#FFA500',
   orangered: '#FF4500',
   orchid: '#DA70D6',
   palegoldenrod: '#EEE8AA',
   palegreen: '#98FB98',
   paleturquoise: '#AFEEEE',
   palevioletred: '#DB7093',
   papayawhip: '#FFEFD5',
   peachpuff: '#FFDAB9',
   peru: '#CD853F',
   pink: '#FFC0CB',
   plum: '#DDA0DD',
   powderblue: '#B0E0E6',
   rosybrown: '#BC8F8F',
   royalblue: '#4169E1',
   saddlebrown: '#8B4513',
   salmon: '#FA8072',
   sandybrown: '#F4A460',
   seagreen: '#2E8B57',
   seashell: '#FFF5EE',
   sienna: '#A0522D',
   skyblue: '#87CEEB',
   slateblue: '#6A5ACD',
   slategray: '#708090',
   slategrey: '#708090',
   snow: '#FFFAFA',
   springgreen: '#00FF7F',
   steelblue: '#4682B4',
   tan: '#D2B48C',
   thistle: '#D8BFD8',
   tomato: '#FF6347',
   turquoise: '#40E0D0',
   violet: '#EE82EE',
   wheat: '#F5DEB3',
   whitesmoke: '#F5F5F5',
   yellowgreen: '#9ACD32'
 };


 function getRgbHslContent(styleString) {
   var start = styleString.indexOf('(', 3);
   var end = styleString.indexOf(')', start + 1);
   var parts = styleString.substring(start + 1, end).split(',');
   // add alpha if needed
   if (parts.length != 4 || styleString.charAt(3) != 'a') {
     parts[3] = 1;
   }
   return parts;
 }
 function percent(s) {
   return parseFloat(s) / 100;
 }
 function clamp(v, min, max) {
   return Math.min(max, Math.max(min, v));
 }
 function hslToRgb(parts){
   var r, g, b, h, s, l;
   h = parseFloat(parts[0]) / 360 % 360;
   if (h < 0)
     h++;
   s = clamp(percent(parts[1]), 0, 1);
   l = clamp(percent(parts[2]), 0, 1);
   if (s == 0) {
     r = g = b = l; // achromatic
   } else {
     var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
     var p = 2 * l - q;
     r = hueToRgb(p, q, h + 1 / 3);
     g = hueToRgb(p, q, h);
     b = hueToRgb(p, q, h - 1 / 3);
   }
   return '#' + decToHex[Math.floor(r * 255)] +
       decToHex[Math.floor(g * 255)] +
       decToHex[Math.floor(b * 255)];
 }
 function hueToRgb(m1, m2, h) {
   if (h < 0)
     h++;
   if (h > 1)
     h--;
   if (6 * h < 1)
     return m1 + (m2 - m1) * 6 * h;
   else if (2 * h < 1)
     return m2;
   else if (3 * h < 2)
     return m1 + (m2 - m1) * (2 / 3 - h) * 6;
   else
     return m1;
 }
 var processStyleCache = {};
 function processStyle(styleString) {
   if (styleString in processStyleCache) {
     return processStyleCache[styleString];
   }
   var str, alpha = 1;
   styleString = String(styleString);
   if (styleString.charAt(0) == '#') {
     str = styleString;
   } else if (/^rgb/.test(styleString)) {
     var parts = getRgbHslContent(styleString);
     var str = '#', n;
     for (var i = 0; i < 3; i++) {
       if (parts[i].indexOf('%') != -1) {
         n = Math.floor(percent(parts[i]) * 255);
       } else {
         n = +parts[i];
       }
       str += decToHex[clamp(n, 0, 255)];
     }
     alpha = +parts[3];
   } else if (/^hsl/.test(styleString)) {
     var parts = getRgbHslContent(styleString);
     str = hslToRgb(parts);
     alpha = parts[3];
   } else {
     str = colorData[styleString] || styleString;
   }
   return processStyleCache[styleString] = {color: str, alpha: alpha};
 }
 var DEFAULT_STYLE = {
   style: 'normal',
   variant: 'normal',
   weight: 'normal',
   size: 10,
   family: 'sans-serif'
 };
 // Internal text style cache
 var fontStyleCache = {};
 function processFontStyle(styleString) {
   if (fontStyleCache[styleString]) {
     return fontStyleCache[styleString];
   }
   var el = document.createElement('div');
   var style = el.style;
   try {
     style.font = styleString;
   } catch (ex) {
     // Ignore failures to set to invalid font.
   }
   return fontStyleCache[styleString] = {
     style: style.fontStyle || DEFAULT_STYLE.style,
     variant: style.fontVariant || DEFAULT_STYLE.variant,
     weight: style.fontWeight || DEFAULT_STYLE.weight,
     size: style.fontSize || DEFAULT_STYLE.size,
     family: style.fontFamily || DEFAULT_STYLE.family
   };
 }
 function getComputedStyle(style, element) {
   var computedStyle = {};
   for (var p in style) {
     computedStyle[p] = style[p];
   }
   // Compute the size
   var canvasFontSize = parseFloat(element.currentStyle.fontSize),
       fontSize = parseFloat(style.size);
   if (typeof style.size == 'number') {
     computedStyle.size = style.size;
   } else if (style.size.indexOf('px') != -1) {
     computedStyle.size = fontSize;
   } else if (style.size.indexOf('em') != -1) {
     computedStyle.size = canvasFontSize * fontSize;
   } else if(style.size.indexOf('%') != -1) {
     computedStyle.size = (canvasFontSize / 100) * fontSize;
   } else if (style.size.indexOf('pt') != -1) {
     computedStyle.size = fontSize / .75;
   } else {
     computedStyle.size = canvasFontSize;
   }
   // Different scaling between normal text and VML text. This was found using
   // trial and error to get the same size as non VML text.
   computedStyle.size *= 0.981;
   return computedStyle;
 }
 function buildStyle(style) {
   return style.style + ' ' + style.variant + ' ' + style.weight + ' ' +
       style.size + 'px ' + style.family;
 }
 var lineCapMap = {
   'butt': 'flat',
   'round': 'round'
 };
 function processLineCap(lineCap) {
   return lineCapMap[lineCap] || 'square';
 }
 /**
  * This class implements CanvasRenderingContext2D interface as described by
  * the WHATWG.
  * @param {HTMLElement} canvasElement The element that the 2D context should
  * be associated with
  */
 function CanvasRenderingContext2D_(canvasElement) {
   this.m_ = createMatrixIdentity();
   this.mStack_ = [];
   this.aStack_ = [];
   this.currentPath_ = [];
   // Canvas context properties
   this.strokeStyle = '#000';
   this.fillStyle = '#000';
   this.lineWidth = 1;
   this.lineJoin = 'miter';
   this.lineCap = 'butt';
   this.miterLimit = Z * 1;
   this.globalAlpha = 1;
   this.font = '10px sans-serif';
   this.textAlign = 'left';
   this.textBaseline = 'alphabetic';
   this.canvas = canvasElement;
   var cssText = 'width:' + canvasElement.clientWidth + 'px;height:' +
       canvasElement.clientHeight + 'px;overflow:hidden;position:absolute';
   var el = canvasElement.ownerDocument.createElement('div');
   el.style.cssText = cssText;
   canvasElement.appendChild(el);
   var overlayEl = el.cloneNode(false);
   // Use a non transparent background.
   overlayEl.style.backgroundColor = 'red';
   overlayEl.style.filter = 'alpha(opacity=0)';
   canvasElement.appendChild(overlayEl);
   this.element_ = el;
   this.arcScaleX_ = 1;
   this.arcScaleY_ = 1;
   this.lineScale_ = 1;
 }
 var contextPrototype = CanvasRenderingContext2D_.prototype;
 contextPrototype.clearRect = function() {
   if (this.textMeasureEl_) {
     this.textMeasureEl_.removeNode(true);
     this.textMeasureEl_ = null;
   }
   this.element_.innerHTML = ;
 };
 contextPrototype.beginPath = function() {
   // TODO: Branch current matrix so that save/restore has no effect
   //       as per safari docs.
   this.currentPath_ = [];
 };
 contextPrototype.moveTo = function(aX, aY) {
   var p = getCoords(this, aX, aY);
   this.currentPath_.push({type: 'moveTo', x: p.x, y: p.y});
   this.currentX_ = p.x;
   this.currentY_ = p.y;
 };
 contextPrototype.lineTo = function(aX, aY) {
   var p = getCoords(this, aX, aY);
   this.currentPath_.push({type: 'lineTo', x: p.x, y: p.y});
   this.currentX_ = p.x;
   this.currentY_ = p.y;
 };
 contextPrototype.bezierCurveTo = function(aCP1x, aCP1y,
                                           aCP2x, aCP2y,
                                           aX, aY) {
   var p = getCoords(this, aX, aY);
   var cp1 = getCoords(this, aCP1x, aCP1y);
   var cp2 = getCoords(this, aCP2x, aCP2y);
   bezierCurveTo(this, cp1, cp2, p);
 };
 // Helper function that takes the already fixed cordinates.
 function bezierCurveTo(self, cp1, cp2, p) {
   self.currentPath_.push({
     type: 'bezierCurveTo',
     cp1x: cp1.x,
     cp1y: cp1.y,
     cp2x: cp2.x,
     cp2y: cp2.y,
     x: p.x,
     y: p.y
   });
   self.currentX_ = p.x;
   self.currentY_ = p.y;
 }
 contextPrototype.quadraticCurveTo = function(aCPx, aCPy, aX, aY) {
   // the following is lifted almost directly from
   // http://developer.mozilla.org/en/docs/Canvas_tutorial:Drawing_shapes
   var cp = getCoords(this, aCPx, aCPy);
   var p = getCoords(this, aX, aY);
   var cp1 = {
     x: this.currentX_ + 2.0 / 3.0 * (cp.x - this.currentX_),
     y: this.currentY_ + 2.0 / 3.0 * (cp.y - this.currentY_)
   };
   var cp2 = {
     x: cp1.x + (p.x - this.currentX_) / 3.0,
     y: cp1.y + (p.y - this.currentY_) / 3.0
   };
   bezierCurveTo(this, cp1, cp2, p);
 };
 contextPrototype.arc = function(aX, aY, aRadius,
                                 aStartAngle, aEndAngle, aClockwise) {
   aRadius *= Z;
   var arcType = aClockwise ? 'at' : 'wa';
   var xStart = aX + mc(aStartAngle) * aRadius - Z2;
   var yStart = aY + ms(aStartAngle) * aRadius - Z2;
   var xEnd = aX + mc(aEndAngle) * aRadius - Z2;
   var yEnd = aY + ms(aEndAngle) * aRadius - Z2;
   // IE won't render arches drawn counter clockwise if xStart == xEnd.
   if (xStart == xEnd && !aClockwise) {
     xStart += 0.125; // Offset xStart by 1/80 of a pixel. Use something
                      // that can be represented in binary
   }
   var p = getCoords(this, aX, aY);
   var pStart = getCoords(this, xStart, yStart);
   var pEnd = getCoords(this, xEnd, yEnd);
   this.currentPath_.push({type: arcType,
                          x: p.x,
                          y: p.y,
                          radius: aRadius,
                          xStart: pStart.x,
                          yStart: pStart.y,
                          xEnd: pEnd.x,
                          yEnd: pEnd.y});
 };
 contextPrototype.rect = function(aX, aY, aWidth, aHeight) {
   this.moveTo(aX, aY);
   this.lineTo(aX + aWidth, aY);
   this.lineTo(aX + aWidth, aY + aHeight);
   this.lineTo(aX, aY + aHeight);
   this.closePath();
 };
 contextPrototype.strokeRect = function(aX, aY, aWidth, aHeight) {
   var oldPath = this.currentPath_;
   this.beginPath();
   this.moveTo(aX, aY);
   this.lineTo(aX + aWidth, aY);
   this.lineTo(aX + aWidth, aY + aHeight);
   this.lineTo(aX, aY + aHeight);
   this.closePath();
   this.stroke();
   this.currentPath_ = oldPath;
 };
 contextPrototype.fillRect = function(aX, aY, aWidth, aHeight) {
   var oldPath = this.currentPath_;
   this.beginPath();
   this.moveTo(aX, aY);
   this.lineTo(aX + aWidth, aY);
   this.lineTo(aX + aWidth, aY + aHeight);
   this.lineTo(aX, aY + aHeight);
   this.closePath();
   this.fill();
   this.currentPath_ = oldPath;
 };
 contextPrototype.createLinearGradient = function(aX0, aY0, aX1, aY1) {
   var gradient = new CanvasGradient_('gradient');
   gradient.x0_ = aX0;
   gradient.y0_ = aY0;
   gradient.x1_ = aX1;
   gradient.y1_ = aY1;
   return gradient;
 };
 contextPrototype.createRadialGradient = function(aX0, aY0, aR0,
                                                  aX1, aY1, aR1) {
   var gradient = new CanvasGradient_('gradientradial');
   gradient.x0_ = aX0;
   gradient.y0_ = aY0;
   gradient.r0_ = aR0;
   gradient.x1_ = aX1;
   gradient.y1_ = aY1;
   gradient.r1_ = aR1;
   return gradient;
 };
 contextPrototype.drawImage = function(image, var_args) {
   var dx, dy, dw, dh, sx, sy, sw, sh;
   // to find the original width we overide the width and height
   var oldRuntimeWidth = image.runtimeStyle.width;
   var oldRuntimeHeight = image.runtimeStyle.height;
   image.runtimeStyle.width = 'auto';
   image.runtimeStyle.height = 'auto';
   // get the original size
   var w = image.width;
   var h = image.height;
   // and remove overides
   image.runtimeStyle.width = oldRuntimeWidth;
   image.runtimeStyle.height = oldRuntimeHeight;
   if (arguments.length == 3) {
     dx = arguments[1];
     dy = arguments[2];
     sx = sy = 0;
     sw = dw = w;
     sh = dh = h;
   } else if (arguments.length == 5) {
     dx = arguments[1];
     dy = arguments[2];
     dw = arguments[3];
     dh = arguments[4];
     sx = sy = 0;
     sw = w;
     sh = h;
   } else if (arguments.length == 9) {
     sx = arguments[1];
     sy = arguments[2];
     sw = arguments[3];
     sh = arguments[4];
     dx = arguments[5];
     dy = arguments[6];
     dw = arguments[7];
     dh = arguments[8];
   } else {
     throw Error('Invalid number of arguments');
   }
   var d = getCoords(this, dx, dy);
   var w2 = sw / 2;
   var h2 = sh / 2;
   var vmlStr = [];
   var W = 10;
   var H = 10;
   // For some reason that I've now forgotten, using divs didn't work
   vmlStr.push(' <g_vml_:group',
               ' coordsize="', Z * W, ',', Z * H, '"',
               ' coordorigin="0,0"' ,
               ' style="width:', W, 'px;height:', H, 'px;position:absolute;');
   // If filters are necessary (rotation exists), create them
   // filters are bog-slow, so only create them if abbsolutely necessary
   // The following check doesn't account for skews (which don't exist
   // in the canvas spec (yet) anyway.
   if (this.m_[0][0] != 1 || this.m_[0][1] ||
       this.m_[1][1] != 1 || this.m_[1][0]) {
     var filter = [];
     // Note the 12/21 reversal
     filter.push('M11=', this.m_[0][0], ',',
                 'M12=', this.m_[1][0], ',',
                 'M21=', this.m_[0][1], ',',
                 'M22=', this.m_[1][1], ',',
                 'Dx=', mr(d.x / Z), ',',
                 'Dy=', mr(d.y / Z), );
     // Bounding box calculation (need to minimize displayed area so that
     // filters don't waste time on unused pixels.
     var max = d;
     var c2 = getCoords(this, dx + dw, dy);
     var c3 = getCoords(this, dx, dy + dh);
     var c4 = getCoords(this, dx + dw, dy + dh);
     max.x = m.max(max.x, c2.x, c3.x, c4.x);
     max.y = m.max(max.y, c2.y, c3.y, c4.y);
     vmlStr.push('padding:0 ', mr(max.x / Z), 'px ', mr(max.y / Z),
                 'px 0;filter:progid:DXImageTransform.Microsoft.Matrix(',
                 filter.join(), ", sizingmethod='clip');");
   } else {
     vmlStr.push('top:', mr(d.y / Z), 'px;left:', mr(d.x / Z), 'px;');
   }

var opacity = ~~(this.globalAlpha * 100);

   vmlStr.push(' ">' ,
               '<g_vml_:image src="', image.src, '"',
               ' style="width:', Z * dw, 'px;',
               ' height:', Z * dh, 'px;',
               ' -ms-filter:progid:DXImageTransform.Microsoft.Alpha(Opacity=', opacity, ');',
               ' filter:alpha(opacity=', opacity, ')"',
               ' cropleft="', sx / w, '"',
               ' croptop="', sy / h, '"',
               ' cropright="', (w - sx - sw) / w, '"',
               ' cropbottom="', (h - sy - sh) / h, '"',
               ' />',
               '</g_vml_:group>');
   this.element_.insertAdjacentHTML('BeforeEnd', vmlStr.join());
 };
 contextPrototype.stroke = function(aFill) {
   var lineStr = [];
   var lineOpen = false;
   var W = 10;
   var H = 10;
   lineStr.push('<g_vml_:shape',
                ' filled="', !!aFill, '"',
                ' style="position:absolute;width:', W, 'px;height:', H, 'px;"',
                ' coordorigin="0,0"',
                ' coordsize="', Z * W, ',', Z * H, '"',
                ' stroked="', !aFill, '"',
                ' path="');
   var newSeq = false;
   var min = {x: null, y: null};
   var max = {x: null, y: null};
   for (var i = 0; i < this.currentPath_.length; i++) {
     var p = this.currentPath_[i];
     var c;
     switch (p.type) {
       case 'moveTo':
         c = p;
         lineStr.push(' m ', mr(p.x), ',', mr(p.y));
         break;
       case 'lineTo':
         lineStr.push(' l ', mr(p.x), ',', mr(p.y));
         break;
       case 'close':
         lineStr.push(' x ');
         p = null;
         break;
       case 'bezierCurveTo':
         lineStr.push(' c ',
                      mr(p.cp1x), ',', mr(p.cp1y), ',',
                      mr(p.cp2x), ',', mr(p.cp2y), ',',
                      mr(p.x), ',', mr(p.y));
         break;
       case 'at':
       case 'wa':
         lineStr.push(' ', p.type, ' ',
                      mr(p.x - this.arcScaleX_ * p.radius), ',',
                      mr(p.y - this.arcScaleY_ * p.radius), ' ',
                      mr(p.x + this.arcScaleX_ * p.radius), ',',
                      mr(p.y + this.arcScaleY_ * p.radius), ' ',
                      mr(p.xStart), ',', mr(p.yStart), ' ',
                      mr(p.xEnd), ',', mr(p.yEnd));
         break;
     }


     // TODO: Following is broken for curves due to
     //       move to proper paths.
     // Figure out dimensions so we can do gradient fills
     // properly
     if (p) {
       if (min.x == null || p.x < min.x) {
         min.x = p.x;
       }
       if (max.x == null || p.x > max.x) {
         max.x = p.x;
       }
       if (min.y == null || p.y < min.y) {
         min.y = p.y;
       }
       if (max.y == null || p.y > max.y) {
         max.y = p.y;
       }
     }
   }
   lineStr.push(' ">');
   if (!aFill) {
     appendStroke(this, lineStr);
   } else {
     appendFill(this, lineStr, min, max);
   }
   lineStr.push('</g_vml_:shape>');
   this.element_.insertAdjacentHTML('beforeEnd', lineStr.join());
 };
 function appendStroke(ctx, lineStr) {
   var a = processStyle(ctx.strokeStyle);
   var color = a.color;
   var opacity = a.alpha * ctx.globalAlpha;
   var lineWidth = ctx.lineScale_ * ctx.lineWidth;
   // VML cannot correctly render a line if the width is less than 1px.
   // In that case, we dilute the color to make the line look thinner.
   if (lineWidth < 1) {
     opacity *= lineWidth;
   }
   lineStr.push(
     '<g_vml_:stroke',
     ' opacity="', opacity, '"',
     ' joinstyle="', ctx.lineJoin, '"',
     ' miterlimit="', ctx.miterLimit, '"',
     ' endcap="', processLineCap(ctx.lineCap), '"',
     ' weight="', lineWidth, 'px"',
     ' color="', color, '" />'
   );
 }
 function appendFill(ctx, lineStr, min, max) {
   var fillStyle = ctx.fillStyle;
   var arcScaleX = ctx.arcScaleX_;
   var arcScaleY = ctx.arcScaleY_;
   var width = max.x - min.x;
   var height = max.y - min.y;
   if (fillStyle instanceof CanvasGradient_) {
     // TODO: Gradients transformed with the transformation matrix.
     var angle = 0;
     var focus = {x: 0, y: 0};
     // additional offset
     var shift = 0;
     // scale factor for offset
     var expansion = 1;
     if (fillStyle.type_ == 'gradient') {
       var x0 = fillStyle.x0_ / arcScaleX;
       var y0 = fillStyle.y0_ / arcScaleY;
       var x1 = fillStyle.x1_ / arcScaleX;
       var y1 = fillStyle.y1_ / arcScaleY;
       var p0 = getCoords(ctx, x0, y0);
       var p1 = getCoords(ctx, x1, y1);
       var dx = p1.x - p0.x;
       var dy = p1.y - p0.y;
       angle = Math.atan2(dx, dy) * 180 / Math.PI;
       // The angle should be a non-negative number.
       if (angle < 0) {
         angle += 360;
       }
       // Very small angles produce an unexpected result because they are
       // converted to a scientific notation string.
       if (angle < 1e-6) {
         angle = 0;
       }
     } else {
       var p0 = getCoords(ctx, fillStyle.x0_, fillStyle.y0_);
       focus = {
         x: (p0.x - min.x) / width,
         y: (p0.y - min.y) / height
       };
       width  /= arcScaleX * Z;
       height /= arcScaleY * Z;
       var dimension = m.max(width, height);
       shift = 2 * fillStyle.r0_ / dimension;
       expansion = 2 * fillStyle.r1_ / dimension - shift;
     }
     // We need to sort the color stops in ascending order by offset,
     // otherwise IE won't interpret it correctly.
     var stops = fillStyle.colors_;
     stops.sort(function(cs1, cs2) {
       return cs1.offset - cs2.offset;
     });
     var length = stops.length;
     var color1 = stops[0].color;
     var color2 = stops[length - 1].color;
     var opacity1 = stops[0].alpha * ctx.globalAlpha;
     var opacity2 = stops[length - 1].alpha * ctx.globalAlpha;
     var colors = [];
     for (var i = 0; i < length; i++) {
       var stop = stops[i];
       colors.push(stop.offset * expansion + shift + ' ' + stop.color);
     }
     // When colors attribute is used, the meanings of opacity and o:opacity2
     // are reversed.
     lineStr.push('<g_vml_:fill type="', fillStyle.type_, '"',
                  ' method="none" focus="100%"',
                  ' color="', color1, '"',
                  ' color2="', color2, '"',
                  ' colors="', colors.join(','), '"',
                  ' opacity="', opacity2, '"',
                  ' g_o_:opacity2="', opacity1, '"',
                  ' angle="', angle, '"',
                  ' focusposition="', focus.x, ',', focus.y, '" />');
   } else if (fillStyle instanceof CanvasPattern_) {
     if (width && height) {
       var deltaLeft = -min.x;
       var deltaTop = -min.y;
       lineStr.push('<g_vml_:fill',
                    ' position="',
                    deltaLeft / width * arcScaleX * arcScaleX, ',',
                    deltaTop / height * arcScaleY * arcScaleY, '"',
                    ' type="tile"',
                    // TODO: Figure out the correct size to fit the scale.
                    //' size="', w, 'px ', h, 'px"',
                    ' src="', fillStyle.src_, '" />');
      }
   } else {
     var a = processStyle(ctx.fillStyle);
     var color = a.color;
     var opacity = a.alpha * ctx.globalAlpha;
     lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity,
                  '" />');
   }
 }
 contextPrototype.fill = function() {
   this.stroke(true);
 };
 contextPrototype.closePath = function() {
   this.currentPath_.push({type: 'close'});
 };
 function getCoords(ctx, aX, aY) {
   var m = ctx.m_;
   return {
     x: Z * (aX * m[0][0] + aY * m[1][0] + m[2][0]) - Z2,
     y: Z * (aX * m[0][1] + aY * m[1][1] + m[2][1]) - Z2
   };
 };
 contextPrototype.save = function() {
   var o = {};
   copyState(this, o);
   this.aStack_.push(o);
   this.mStack_.push(this.m_);
   this.m_ = matrixMultiply(createMatrixIdentity(), this.m_);
 };
 contextPrototype.restore = function() {
   if (this.aStack_.length) {
     copyState(this.aStack_.pop(), this);
     this.m_ = this.mStack_.pop();
   }
 };
 function matrixIsFinite(m) {
   return isFinite(m[0][0]) && isFinite(m[0][1]) &&
       isFinite(m[1][0]) && isFinite(m[1][1]) &&
       isFinite(m[2][0]) && isFinite(m[2][1]);
 }
 function setM(ctx, m, updateLineScale) {
   if (!matrixIsFinite(m)) {
     return;
   }
   ctx.m_ = m;
   if (updateLineScale) {
     // Get the line scale.
     // Determinant of this.m_ means how much the area is enlarged by the
     // transformation. So its square root can be used as a scale factor
     // for width.
     var det = m[0][0] * m[1][1] - m[0][1] * m[1][0];
     ctx.lineScale_ = sqrt(abs(det));
   }
 }
 contextPrototype.translate = function(aX, aY) {
   var m1 = [
     [1,  0,  0],
     [0,  1,  0],
     [aX, aY, 1]
   ];
   setM(this, matrixMultiply(m1, this.m_), false);
 };
 contextPrototype.rotate = function(aRot) {
   var c = mc(aRot);
   var s = ms(aRot);
   var m1 = [
     [c,  s, 0],
     [-s, c, 0],
     [0,  0, 1]
   ];
   setM(this, matrixMultiply(m1, this.m_), false);
 };
 contextPrototype.scale = function(aX, aY) {
   this.arcScaleX_ *= aX;
   this.arcScaleY_ *= aY;
   var m1 = [
     [aX, 0,  0],
     [0,  aY, 0],
     [0,  0,  1]
   ];
   setM(this, matrixMultiply(m1, this.m_), true);
 };
 contextPrototype.transform = function(m11, m12, m21, m22, dx, dy) {
   var m1 = [
     [m11, m12, 0],
     [m21, m22, 0],
     [dx,  dy,  1]
   ];
   setM(this, matrixMultiply(m1, this.m_), true);
 };
 contextPrototype.setTransform = function(m11, m12, m21, m22, dx, dy) {
   var m = [
     [m11, m12, 0],
     [m21, m22, 0],
     [dx,  dy,  1]
   ];
   setM(this, m, true);
 };
 /**
  * The text drawing function.
  * The maxWidth argument isn't taken in account, since no browser supports
  * it yet.
  */
 contextPrototype.drawText_ = function(text, x, y, maxWidth, stroke) {
   var m = this.m_,
       delta = 1000,
       left = 0,
       right = delta,
       offset = {x: 0, y: 0},
       lineStr = [];
   var fontStyle = getComputedStyle(processFontStyle(this.font),
                                    this.element_);
   var fontStyleString = buildStyle(fontStyle);
   var elementStyle = this.element_.currentStyle;
   var textAlign = this.textAlign.toLowerCase();
   switch (textAlign) {
     case 'left':
     case 'center':
     case 'right':
       break;
     case 'end':
       textAlign = elementStyle.direction == 'ltr' ? 'right' : 'left';
       break;
     case 'start':
       textAlign = elementStyle.direction == 'rtl' ? 'right' : 'left';
       break;
     default:
       textAlign = 'left';
   }
   // 1.75 is an arbitrary number, as there is no info about the text baseline
   switch (this.textBaseline) {
     case 'hanging':
     case 'top':
       offset.y = fontStyle.size / 1.75;
       break;
     case 'middle':
       break;
     default:
     case null:
     case 'alphabetic':
     case 'ideographic':
     case 'bottom':
       offset.y = -fontStyle.size / 2.25;
       break;
   }
   switch(textAlign) {
     case 'right':
       left = delta;
       right = 0.05;
       break;
     case 'center':
       left = right = delta / 2;
       break;
   }
   var d = getCoords(this, x + offset.x, y + offset.y);
   lineStr.push('<g_vml_:line from="', -left ,' 0" to="', right ,' 0.05" ',
                ' coordsize="100 100" coordorigin="0 0"',
                ' filled="', !stroke, '" stroked="', !!stroke,
                '" style="position:absolute;width:1px;height:1px;">');
   if (stroke) {
     appendStroke(this, lineStr);
   } else {
     // TODO: Fix the min and max params.
     appendFill(this, lineStr, {x: -left, y: 0},
                {x: right, y: fontStyle.size});
   }
   var skewM = m[0][0].toFixed(3) + ',' + m[1][0].toFixed(3) + ',' +
               m[0][1].toFixed(3) + ',' + m[1][1].toFixed(3) + ',0,0';
   var skewOffset = mr(d.x / Z) + ',' + mr(d.y / Z);
   lineStr.push('<g_vml_:skew on="t" matrix="', skewM ,'" ',
                ' offset="', skewOffset, '" origin="', left ,' 0" />',
                '<g_vml_:path textpathok="true" />',
                '<g_vml_:textpath on="true" string="',
                encodeHtmlAttribute(text),
                '" style="v-text-align:', textAlign,
                ';font:', encodeHtmlAttribute(fontStyleString),
                '" /></g_vml_:line>');
   this.element_.insertAdjacentHTML('beforeEnd', lineStr.join());
 };
 contextPrototype.fillText = function(text, x, y, maxWidth) {
   this.drawText_(text, x, y, maxWidth, false);
 };
 contextPrototype.strokeText = function(text, x, y, maxWidth) {
   this.drawText_(text, x, y, maxWidth, true);
 };
 contextPrototype.measureText = function(text) {
   if (!this.textMeasureEl_) {
     var s = '';
     this.element_.insertAdjacentHTML('beforeEnd', s);
     this.textMeasureEl_ = this.element_.lastChild;
   }
   var doc = this.element_.ownerDocument;
   this.textMeasureEl_.innerHTML = ;
   this.textMeasureEl_.style.font = this.font;
   // Don't use innerHTML or innerText because they allow markup/whitespace.
   this.textMeasureEl_.appendChild(doc.createTextNode(text));
   return {width: this.textMeasureEl_.offsetWidth};
 };
 /******** STUBS ********/
 contextPrototype.clip = function() {
   // TODO: Implement
 };
 contextPrototype.arcTo = function() {
   // TODO: Implement
 };
 contextPrototype.createPattern = function(image, repetition) {
   return new CanvasPattern_(image, repetition);
 };
 // Gradient / Pattern Stubs
 function CanvasGradient_(aType) {
   this.type_ = aType;
   this.x0_ = 0;
   this.y0_ = 0;
   this.r0_ = 0;
   this.x1_ = 0;
   this.y1_ = 0;
   this.r1_ = 0;
   this.colors_ = [];
 }
 CanvasGradient_.prototype.addColorStop = function(aOffset, aColor) {
   aColor = processStyle(aColor);
   this.colors_.push({offset: aOffset,
                      color: aColor.color,
                      alpha: aColor.alpha});
 };
 function CanvasPattern_(image, repetition) {
   assertImageIsValid(image);
   switch (repetition) {
     case 'repeat':
     case null:
     case :
       this.repetition_ = 'repeat';
       break
     case 'repeat-x':
     case 'repeat-y':
     case 'no-repeat':
       this.repetition_ = repetition;
       break;
     default:
       throwException('SYNTAX_ERR');
   }
   this.src_ = image.src;
   this.width_ = image.width;
   this.height_ = image.height;
 }
 function throwException(s) {
   throw new DOMException_(s);
 }
 function assertImageIsValid(img) {
   if (!img || img.nodeType != 1 || img.tagName != 'IMG') {
     throwException('TYPE_MISMATCH_ERR');
   }
   if (img.readyState != 'complete') {
     throwException('INVALID_STATE_ERR');
   }
 }
 function DOMException_(s) {
   this.code = this[s];
   this.message = s +': DOM Exception ' + this.code;
 }
 var p = DOMException_.prototype = new Error;
 p.INDEX_SIZE_ERR = 1;
 p.DOMSTRING_SIZE_ERR = 2;
 p.HIERARCHY_REQUEST_ERR = 3;
 p.WRONG_DOCUMENT_ERR = 4;
 p.INVALID_CHARACTER_ERR = 5;
 p.NO_DATA_ALLOWED_ERR = 6;
 p.NO_MODIFICATION_ALLOWED_ERR = 7;
 p.NOT_FOUND_ERR = 8;
 p.NOT_SUPPORTED_ERR = 9;
 p.INUSE_ATTRIBUTE_ERR = 10;
 p.INVALID_STATE_ERR = 11;
 p.SYNTAX_ERR = 12;
 p.INVALID_MODIFICATION_ERR = 13;
 p.NAMESPACE_ERR = 14;
 p.INVALID_ACCESS_ERR = 15;
 p.VALIDATION_ERR = 16;
 p.TYPE_MISMATCH_ERR = 17;
 // set up externs
 G_vmlCanvasManager = G_vmlCanvasManager_;
 CanvasRenderingContext2D = CanvasRenderingContext2D_;
 CanvasGradient = CanvasGradient_;
 CanvasPattern = CanvasPattern_;
 DOMException = DOMException_;

})();

} // if </script>

</html>