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Diffstat (limited to 'excanvas.js')
| -rw-r--r-- | excanvas.js | 785 |
1 files changed, 785 insertions, 0 deletions
diff --git a/excanvas.js b/excanvas.js new file mode 100644 index 0000000..7914cb9 --- /dev/null +++ b/excanvas.js @@ -0,0 +1,785 @@ +// 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 are not implemented. +// * 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) +// * Optimize. There is always room for speed improvements. + +// only add this code if we do not already have a canvas implementation +if (!window.CanvasRenderingContext2D) { + +(function () { + + // alias some functions to make (compiled) code shorter + var m = Math; + var mr = m.round; + var ms = m.sin; + var mc = m.cos; + + // this is used for sub pixel precision + var Z = 10; + var Z2 = Z / 2; + + var G_vmlCanvasManager_ = { + init: function (opt_doc) { + var doc = opt_doc || document; + if (/MSIE/.test(navigator.userAgent) && !window.opera) { + var self = this; + doc.attachEvent("onreadystatechange", function () { + self.init_(doc); + }); + } + }, + + init_: function (doc) { + if (doc.readyState == "complete") { + // create xmlns + if (!doc.namespaces["g_vml_"]) { + doc.namespaces.add("g_vml_", "urn:schemas-microsoft-com:vml"); + } + + // setup default css + var ss = doc.createStyleSheet(); + ss.cssText = "canvas{display:inline-block;overflow:hidden;" + + // default size is 300x150 in Gecko and Opera + "text-align:left;width:300px;height:150px}" + + "g_vml_\\:*{behavior:url(#default#VML)}"; + + // find all canvas elements + var els = doc.getElementsByTagName("canvas"); + for (var i = 0; i < els.length; i++) { + if (!els[i].getContext) { + this.initElement(els[i]); + } + } + } + }, + + fixElement_: function (el) { + // in IE before version 5.5 we would need to add HTML: to the tag name + // but we do not care about IE before version 6 + var outerHTML = el.outerHTML; + + var newEl = el.ownerDocument.createElement(outerHTML); + // if the tag is still open IE has created the children as siblings and + // it has also created a tag with the name "/FOO" + if (outerHTML.slice(-2) != "/>") { + var tagName = "/" + el.tagName; + var ns; + // remove content + while ((ns = el.nextSibling) && ns.tagName != tagName) { + ns.removeNode(); + } + // remove the incorrect closing tag + if (ns) { + ns.removeNode(); + } + } + el.parentNode.replaceChild(newEl, el); + return newEl; + }, + + /** + * 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) { + el = this.fixElement_(el); + el.getContext = function () { + if (this.context_) { + return this.context_; + } + return this.context_ = new CanvasRenderingContext2D_(this); + }; + + // 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.style.width = el.attributes.width.nodeValue + "px"; + el.getContext().clearRect(); + break; + case 'height': + el.style.height = el.attributes.height.nodeValue + "px"; + el.getContext().clearRect(); + 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 dec2hex = []; + for (var i = 0; i < 16; i++) { + for (var j = 0; j < 16; j++) { + dec2hex[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.arcScaleX_ = o1.arcScaleX_; + o2.arcScaleY_ = o1.arcScaleY_; + } + + function processStyle(styleString) { + var str, alpha = 1; + + styleString = String(styleString); + if (styleString.substring(0, 3) == "rgb") { + var start = styleString.indexOf("(", 3); + var end = styleString.indexOf(")", start + 1); + var guts = styleString.substring(start + 1, end).split(","); + + str = "#"; + for (var i = 0; i < 3; i++) { + str += dec2hex[Number(guts[i])]; + } + + if ((guts.length == 4) && (styleString.substr(3, 1) == "a")) { + alpha = guts[3]; + } + } else { + str = styleString; + } + + return [str, alpha]; + } + + 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.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; + } + + var contextPrototype = CanvasRenderingContext2D_.prototype; + contextPrototype.clearRect = function() { + this.element_.innerHTML = ""; + this.currentPath_ = []; + }; + + 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) { + this.currentPath_.push({type: "moveTo", x: aX, y: aY}); + this.currentX_ = aX; + this.currentY_ = aY; + }; + + contextPrototype.lineTo = function(aX, aY) { + this.currentPath_.push({type: "lineTo", x: aX, y: aY}); + this.currentX_ = aX; + this.currentY_ = aY; + }; + + contextPrototype.bezierCurveTo = function(aCP1x, aCP1y, + aCP2x, aCP2y, + aX, aY) { + this.currentPath_.push({type: "bezierCurveTo", + cp1x: aCP1x, + cp1y: aCP1y, + cp2x: aCP2x, + cp2y: aCP2y, + x: aX, + y: aY}); + this.currentX_ = aX; + this.currentY_ = aY; + }; + + 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 cp1x = this.currentX_ + 2.0 / 3.0 * (aCPx - this.currentX_); + var cp1y = this.currentY_ + 2.0 / 3.0 * (aCPy - this.currentY_); + var cp2x = cp1x + (aX - this.currentX_) / 3.0; + var cp2y = cp1y + (aY - this.currentY_) / 3.0; + this.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, aX, aY); + }; + + 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 + } + + this.currentPath_.push({type: arcType, + x: aX, + y: aY, + radius: aRadius, + xStart: xStart, + yStart: yStart, + xEnd: xEnd, + yEnd: yEnd}); + + }; + + 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) { + // Will destroy any existing path (same as FF behaviour) + 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(); + }; + + contextPrototype.fillRect = function(aX, aY, aWidth, aHeight) { + // Will destroy any existing path (same as FF behaviour) + 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(); + }; + + contextPrototype.createLinearGradient = function(aX0, aY0, aX1, aY1) { + var gradient = new CanvasGradient_("gradient"); + return gradient; + }; + + contextPrototype.createRadialGradient = function(aX0, aY0, + aR0, aX1, + aY1, aR1) { + var gradient = new CanvasGradient_("gradientradial"); + gradient.radius1_ = aR0; + gradient.radius2_ = aR1; + gradient.focus_.x = aX0; + gradient.focus_.y = aY0; + 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 "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, ';height:', H, ';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]) { + 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 = Math.max(max.x, c2.x, c3.x, c4.x); + max.y = Math.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, ';', + ' height:', Z * dh, ';"', + ' 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 a = processStyle(aFill ? this.fillStyle : this.strokeStyle); + var color = a[0]; + var opacity = a[1] * this.globalAlpha; + + var W = 10; + var H = 10; + + lineStr.push('<g_vml_:shape', + ' fillcolor="', color, '"', + ' filled="', Boolean(aFill), '"', + ' style="position:absolute;width:', W, ';height:', H, ';"', + ' coordorigin="0 0" coordsize="', Z * W, ' ', Z * H, '"', + ' stroked="', !aFill, '"', + ' strokeweight="', this.lineWidth, '"', + ' strokecolor="', color, '"', + ' 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]; + + if (p.type == "moveTo") { + lineStr.push(" m "); + var c = this.getCoords_(p.x, p.y); + lineStr.push(mr(c.x), ",", mr(c.y)); + } else if (p.type == "lineTo") { + lineStr.push(" l "); + var c = this.getCoords_(p.x, p.y); + lineStr.push(mr(c.x), ",", mr(c.y)); + } else if (p.type == "close") { + lineStr.push(" x "); + } else if (p.type == "bezierCurveTo") { + lineStr.push(" c "); + var c = this.getCoords_(p.x, p.y); + var c1 = this.getCoords_(p.cp1x, p.cp1y); + var c2 = this.getCoords_(p.cp2x, p.cp2y); + lineStr.push(mr(c1.x), ",", mr(c1.y), ",", + mr(c2.x), ",", mr(c2.y), ",", + mr(c.x), ",", mr(c.y)); + } else if (p.type == "at" || p.type == "wa") { + lineStr.push(" ", p.type, " "); + var c = this.getCoords_(p.x, p.y); + var cStart = this.getCoords_(p.xStart, p.yStart); + var cEnd = this.getCoords_(p.xEnd, p.yEnd); + + lineStr.push(mr(c.x - this.arcScaleX_ * p.radius), ",", + mr(c.y - this.arcScaleY_ * p.radius), " ", + mr(c.x + this.arcScaleX_ * p.radius), ",", + mr(c.y + this.arcScaleY_ * p.radius), " ", + mr(cStart.x), ",", mr(cStart.y), " ", + mr(cEnd.x), ",", mr(cEnd.y)); + } + + + // TODO: Following is broken for curves due to + // move to proper paths. + + // Figure out dimensions so we can do gradient fills + // properly + if(c) { + if (min.x == null || c.x < min.x) { + min.x = c.x; + } + if (max.x == null || c.x > max.x) { + max.x = c.x; + } + if (min.y == null || c.y < min.y) { + min.y = c.y; + } + if (max.y == null || c.y > max.y) { + max.y = c.y; + } + } + } + lineStr.push(' ">'); + + if (typeof this.fillStyle == "object") { + var focus = {x: "50%", y: "50%"}; + var width = (max.x - min.x); + var height = (max.y - min.y); + var dimension = (width > height) ? width : height; + + focus.x = mr((this.fillStyle.focus_.x / width) * 100 + 50) + "%"; + focus.y = mr((this.fillStyle.focus_.y / height) * 100 + 50) + "%"; + + var colors = []; + + // inside radius (%) + if (this.fillStyle.type_ == "gradientradial") { + var inside = (this.fillStyle.radius1_ / dimension * 100); + + // percentage that outside radius exceeds inside radius + var expansion = (this.fillStyle.radius2_ / dimension * 100) - inside; + } else { + var inside = 0; + var expansion = 100; + } + + var insidecolor = {offset: null, color: null}; + var outsidecolor = {offset: null, color: null}; + + // We need to sort 'colors' by percentage, from 0 > 100 otherwise ie + // won't interpret it correctly + this.fillStyle.colors_.sort(function (cs1, cs2) { + return cs1.offset - cs2.offset; + }); + + for (var i = 0; i < this.fillStyle.colors_.length; i++) { + var fs = this.fillStyle.colors_[i]; + + colors.push( (fs.offset * expansion) + inside, "% ", fs.color, ","); + + if (fs.offset > insidecolor.offset || insidecolor.offset == null) { + insidecolor.offset = fs.offset; + insidecolor.color = fs.color; + } + + if (fs.offset < outsidecolor.offset || outsidecolor.offset == null) { + outsidecolor.offset = fs.offset; + outsidecolor.color = fs.color; + } + } + colors.pop(); + + lineStr.push('<g_vml_:fill', + ' color="', outsidecolor.color, '"', + ' color2="', insidecolor.color, '"', + ' type="', this.fillStyle.type_, '"', + ' focusposition="', focus.x, ', ', focus.y, '"', + ' colors="', colors.join(""), '"', + ' opacity="', opacity, '" />'); + } else if (aFill) { + lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity, '" />'); + } else { + lineStr.push( + '<g_vml_:stroke', + ' opacity="', opacity,'"', + ' joinstyle="', this.lineJoin, '"', + ' miterlimit="', this.miterLimit, '"', + ' endcap="', processLineCap(this.lineCap) ,'"', + ' weight="', this.lineWidth, 'px"', + ' color="', color,'" />' + ); + } + + lineStr.push("</g_vml_:shape>"); + + this.element_.insertAdjacentHTML("beforeEnd", lineStr.join("")); + + //this.currentPath_ = []; + }; + + contextPrototype.fill = function() { + this.stroke(true); + }; + + contextPrototype.closePath = function() { + this.currentPath_.push({type: "close"}); + }; + + /** + * @private + */ + contextPrototype.getCoords_ = function(aX, aY) { + return { + x: Z * (aX * this.m_[0][0] + aY * this.m_[1][0] + this.m_[2][0]) - Z2, + y: Z * (aX * this.m_[0][1] + aY * this.m_[1][1] + this.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() { + copyState(this.aStack_.pop(), this); + this.m_ = this.mStack_.pop(); + }; + + contextPrototype.translate = function(aX, aY) { + var m1 = [ + [1, 0, 0], + [0, 1, 0], + [aX, aY, 1] + ]; + + this.m_ = matrixMultiply(m1, this.m_); + }; + + contextPrototype.rotate = function(aRot) { + var c = mc(aRot); + var s = ms(aRot); + + var m1 = [ + [c, s, 0], + [-s, c, 0], + [0, 0, 1] + ]; + + this.m_ = matrixMultiply(m1, this.m_); + }; + + contextPrototype.scale = function(aX, aY) { + this.arcScaleX_ *= aX; + this.arcScaleY_ *= aY; + var m1 = [ + [aX, 0, 0], + [0, aY, 0], + [0, 0, 1] + ]; + + this.m_ = matrixMultiply(m1, this.m_); + }; + + /******** STUBS ********/ + contextPrototype.clip = function() { + // TODO: Implement + }; + + contextPrototype.arcTo = function() { + // TODO: Implement + }; + + contextPrototype.createPattern = function() { + return new CanvasPattern_; + }; + + // Gradient / Pattern Stubs + function CanvasGradient_(aType) { + this.type_ = aType; + this.radius1_ = 0; + this.radius2_ = 0; + this.colors_ = []; + this.focus_ = {x: 0, y: 0}; + } + + CanvasGradient_.prototype.addColorStop = function(aOffset, aColor) { + aColor = processStyle(aColor); + this.colors_.push({offset: 1-aOffset, color: aColor}); + }; + + function CanvasPattern_() {} + + // set up externs + G_vmlCanvasManager = G_vmlCanvasManager_; + CanvasRenderingContext2D = CanvasRenderingContext2D_; + CanvasGradient = CanvasGradient_; + CanvasPattern = CanvasPattern_; + +})(); + +} // if |