forked from ryleyb/Flot-Graphs
/
excanvas.js
1427 lines (1245 loc) · 40.8 KB
/
excanvas.js
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// 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.
// 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.
// * Filling very large shapes (above 5000 points) is buggy.
// * 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;
/**
* 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 addNamespacesAndStylesheet(doc) {
// create xmlns
if (!doc.namespaces['g_vml_']) {
doc.namespaces.add('g_vml_', 'urn:schemas-microsoft-com:vml',
'#default#VML');
}
if (!doc.namespaces['g_o_']) {
doc.namespaces.add('g_o_', 'urn:schemas-microsoft-com:office:office',
'#default#VML');
}
// 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) {
if (/MSIE/.test(navigator.userAgent) && !window.opera) {
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.substr(3, 1) == 'a') {
alpha = Number(parts[3]);
} else {
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 = 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;
}
function processStyle(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 = Number(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 {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;
}
function processLineCap(lineCap) {
switch (lineCap) {
case 'butt':
return 'flat';
case 'round':
return 'round';
case 'square':
default:
return 'square';
}
}
/**
* This class implements CanvasRenderingContext2D interface as described by
* the WHATWG.
* @param {HTMLElement} surfaceElement The element that the 2D context should
* be associated with
*/
function CanvasRenderingContext2D_(surfaceElement) {
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 = surfaceElement;
var el = surfaceElement.ownerDocument.createElement('div');
el.style.width = surfaceElement.clientWidth + 'px';
el.style.height = surfaceElement.clientHeight + 'px';
el.style.overflow = 'hidden';
el.style.position = 'absolute';
surfaceElement.appendChild(el);
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 = this.getCoords_(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 = this.getCoords_(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 = this.getCoords_(aX, aY);
var cp1 = this.getCoords_(aCP1x, aCP1y);
var cp2 = this.getCoords_(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 = this.getCoords_(aCPx, aCPy);
var p = this.getCoords_(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 = this.getCoords_(aX, aY);
var pStart = this.getCoords_(xStart, yStart);
var pEnd = this.getCoords_(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 = this.getCoords_(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 = this.getCoords_(dx + dw, dy);
var c3 = this.getCoords_(dx, dy + dh);
var c4 = this.getCoords_(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;');
}
vmlStr.push(' ">' ,
'<g_vml_:image src="', image.src, '"',
' style="width:', Z * dw, 'px;',
' height:', Z * dh, 'px"',
' 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 W = 10;
var H = 10;
// Divide the shape into chunks if it's too long because IE has a limit
// somewhere for how long a VML shape can be. This simple division does
// not work with fills, only strokes, unfortunately.
var chunkSize = 5000;
var min = {x: null, y: null};
var max = {x: null, y: null};
for (var j = 0; j < this.currentPath_.length; j += chunkSize) {
var lineStr = [];
var lineOpen = false;
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;
for (var i = j; i < Math.min(j + chunkSize, this.currentPath_.length); i++) {
if (i % chunkSize == 0 && i > 0) { // move into position for next chunk
lineStr.push(' m ', mr(this.currentPath_[i-1].x), ',', mr(this.currentPath_[i-1].y));
}
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_;