JavaScript DHTML/Ajax Layer/3D
3D Cube
<source lang="html4strict">
<html>
<head>
<title>ExplorerCanvas Example 1</title> <script type="text/javascript">
/* ExplorerCanvas Copyright 2006 Google Inc.
DESCRIPTION Firefox, Safari and Opera 9 support the canvas tag to allow 2D command-based drawing operations. ExplorerCanvas brings the same functionality to Internet Explorer; web developers only need to include a single script tag in their existing canvas webpages to enable this support.
Google Open Source:
<http://code.google.ru> <opensource@google.ru>
Developers:
Emil A Eklund <emil@eae.net> Erik Arvidsson <erik@eae.net> Glen Murphy <glen@glenmurphy.ru>
- /
// 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
</script> <script type="text/javascript"> /* -------------------------------------------------------------------- */ var canvas, ctx; var canvasWidth, halfCanvasWidth; var canvasHeight, halfCanvasHeight; var space; // 3D Engine var scene; // 3D Scene /* -------------------------------------------------------------------- */ /** * Space is a simple 3D system. * * Y+ = up * Z+ = into screen * X+ = right */ function Space() { this.m = this.createMatrixIdentity(); this.mStack = []; } Space.prototype.createMatrixIdentity = function() { return [ [1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1] ]; } /** * Multiplies two 4x4 matricies together. */ Space.prototype.matrixMultiply = function(m1, m2) { var result = this.createMatrixIdentity(); var width = m1[0].length; var height = m1.length; if (width != m2.length) { // error } for (var x = 0; x < width; x++) { for (var y = 0; y < height; y++) { var sum = 0; for (var z = 0; z < width; z++) { sum += m1[y][z] * m2[z][x]; } result[y][x] = sum; } } return result; } /** * Transforms a coordinate using the current transformation * matrix, then flattens it using the projection matrix. */ Space.prototype.flatten = function(point) { var p = point.x, point.y, point.z, 1; var pm = this.matrixMultiply(p, this.m); point.tx = pm[0][0]; point.ty = pm[0][1]; point.tz = pm[0][2]; // lazy projection point.fx = halfCanvasWidth + (canvasWidth * point.tx / point.tz); point.fy = halfCanvasHeight -(canvasWidth * point.ty / point.tz); } /** * Translate (move) the current transformation matrix */ Space.prototype.translate = function(x, y, z) { var m = [ [1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [x, y, z, 1] ]; this.m = this.matrixMultiply(m, this.m); } /** * Rotate the current transformation matrix. Rotations are * world-oriented, and occur in y,x,z order. */ Space.prototype.rotate = function(x, y, z) { if (y) { var cosY = Math.cos(y); var sinY = Math.sin(y); var rotY = [ [cosY, 0, sinY, 0], [0, 1, 0, 0], [-sinY, 0, cosY, 0], [0, 0, 0, 1] ]; this.m = this.matrixMultiply(this.m, rotY); } if (x) { var cosX = Math.cos(x); var sinX = Math.sin(x); var rotX = [ [1, 0, 0, 0], [0, cosX, -sinX, 0], [0, sinX, cosX,0], [0, 0, 0, 1] ]; this.m = this.matrixMultiply(this.m, rotX); } if (z) { var cosZ = Math.cos(z); var sinZ = Math.sin(z); var rotZ = [ [cosZ, -sinZ, 0, 0], [sinZ, cosZ, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1] ]; this.m = this.matrixMultiply(this.m, rotZ); } } /** * Pushes the current transformation onto the stack */ Space.prototype.push = function() { this.mStack.push(this.m); this.m = [ [this.m[0][0], this.m[0][1], this.m[0][2], this.m[0][3]], [this.m[1][0], this.m[1][1], this.m[1][2], this.m[1][3]], [this.m[2][0], this.m[2][1], this.m[2][2], this.m[2][3]], [this.m[3][0], this.m[3][1], this.m[3][2], this.m[3][3]] ]; } /** * Pops the end off the transformation stack */ Space.prototype.pop = function() { this.m = this.mStack.pop(); } /* -------------------------------------------------------------------- */ /** * A 3d coordinate */ function Point(x, y, z) { this.x = x; this.y = y; this.z = z; // Relative to camera coordinates this.tx; this.ty; this.tz; // Flattened coordinates this.fx; this.fy; } /** * A Shape is made up of polygons */ function Shape() { this.points = []; this.polygons = []; } /** * Draws the shape */ Shape.prototype.draw = function(drawlist) { for (var i = 0; i< this.points.length; i++) { space.flatten(this.points[i]); } for (var i = 0; i< this.polygons.length; i++) { var poly = this.polygons[i]; // convenience space.flatten(poly.origin); // lazy backface culling if (poly.normal && this.backface) { space.flatten(poly.normal); var originDist = Math.pow(poly.origin.tx, 2) + Math.pow(poly.origin.ty, 2) + Math.pow(poly.origin.tz, 2); var normalDist = Math.pow(poly.normal.tx, 2) + Math.pow(poly.normal.ty, 2) + Math.pow(poly.normal.tz, 2); if(originDist > normalDist) { drawlist.push(poly); } } else { drawlist.push(poly); } } } /** * A polygon is a connection of points in the shape object. You * should probably try to make them coplanar. */ function Polygon(points, normal, backface, type, color) { this.points = points; this.origin = new Point(0, 0, 0); for(var i = 0; i < this.points.length; i++) { this.origin.x += this.points[i].x; this.origin.y += this.points[i].y; this.origin.z += this.points[i].z; } this.origin.x /= this.points.length; this.origin.y /= this.points.length; this.origin.z /= this.points.length; if (normal) { this.normal = new Point(this.origin.x + normal.x, this.origin.y + normal.y, this.origin.z + normal.z); } else { this.normal = null; } this.backface = backface; this.type = type; this.color = color; } Polygon.SOLID = 0; Polygon.WIRE = 1; /** * Draws the polygon. Assumes that the points have already been * flattened. */ Polygon.prototype.draw = function() { ctx.beginPath(); ctx.moveTo(this.points[0].fx, this.points[0].fy); for(var i = 0; i < this.points.length; i++) { ctx.lineTo(this.points[i].fx, this.points[i].fy); } ctx.closePath(); var color = this.color; /* // Do lighting here lightvector = Math.abs(this.normal.x + this.normal.y); if(lightvector > 1) { lightvector = 1; } color[0] = (color[0] * lightvector).toString(); color[1] = (color[1] * lightvector).toString(); color[2] = (color[2] * lightvector).toString(); */ if (color.length > 3) { var style = ["rgba(", color[0], ",", color[1], ",", color[2], ",", color[3], ")"].join(""); } else { var style = ["rgb(", color[0], ",", color[1], ",", color[2], ")"].join(""); } if (this.type == Polygon.SOLID) { ctx.fillStyle = style; ctx.fill(); } else if (this.type == Polygon.WIRE) { ctx.strokeStyle = style; ctx.stroke(); } } /* -------------------------------------------------------------------- */ /** * Scene describes the 3D environment */ function Scene() { this.shapes = {}; this.camera = new Point(0, 0, 0); this.cameraTarget = new Point(0, 0, 0); this.cameraRotation = 0; this.drawlist = []; } /** * Draw the world */ Scene.prototype.draw = function() { space.push(); // Camera transformation space.translate( -this.camera.x, -this.camera.y, -this.camera.z ); // Camera rotation var xdiff = this.cameraTarget.x - this.camera.x; var ydiff = this.cameraTarget.y - this.camera.y; var zdiff = this.cameraTarget.z - this.camera.z; var xzdist = Math.sqrt(Math.pow(xdiff, 2) + Math.pow(zdiff, 2)); var xrot = -Math.atan2(ydiff, xzdist); // up/down rotation var yrot = Math.atan2(xdiff, zdiff); // left/right rotation space.rotate(xrot, yrot, this.cameraRotation); // Drawing this.drawlist = []; for(var i in this.shapes) { this.shapes[i].draw(this.drawlist); } // Depth sorting (warning: this is only enough to drive this demo - feel // free to contribute a better system). this.drawlist.sort(function (poly1, poly2) { return poly2.origin.tz - poly1.origin.tz; }); for (var i = 0; i < this.drawlist.length; i++) { this.drawlist[i].draw(); } space.pop(); } /* -------------------------------------------------------------------- */ var count = 0; function loop() { ctx.clearRect(0, 0, canvasWidth, canvasHeight); scene.camera.x = 70*Math.sin(count); scene.camera.y = 70; scene.camera.z = 70*Math.cos(count); scene.cameraRotation = count / 10; count += 0.01; scene.draw(); } function load() { // Init drawing system canvas = document.getElementById("cv"); ctx = canvas.getContext("2d"); canvasWidth = canvas.width; canvasHeight = canvas.height; halfCanvasWidth = canvasWidth * 0.5; halfCanvasHeight = canvasHeight * 0.5; // Init 3D components space = new Space(); scene = new Scene(); // Create a box shape and add it to the scene scene.shapes["box"] = new Shape(); var p = scene.shapes["box"].points; // for convenience p[0] = new Point(-10, -10, -10); // left bottom front p[1] = new Point(10, -10, -10); // right bottom front p[2] = new Point(10, 10, -10); // right top front p[3] = new Point(-10, 10, -10); // left top front p[4] = new Point(-10, -10, 10); // left bottom back p[5] = new Point(10, -10, 10); // right bottom back p[6] = new Point(10, 10, 10); // right top back p[7] = new Point(-10, 10, 10); // left top back // Back scene.shapes["box"].polygons.push(new Polygon( [ p[0], p[1], p[2], p[3] ], new Point(0, 0, -1), true /* double-sided */, Polygon.SOLID, [255, 0, 0] )); // Front scene.shapes["box"].polygons.push(new Polygon( [ p[4], p[5], p[6], p[7] ], new Point(0, 0, 1), true /* double-sided */, Polygon.SOLID, [0, 0, 255] )); // Top scene.shapes["box"].polygons.push(new Polygon( [ p[2], p[3], p[7], p[6] ], new Point(0, 1, 0), false /* single-sided */, Polygon.WIRE, [0, 255, 0] )); // Transparent Top scene.shapes["box"].polygons.push(new Polygon( [ p[2], p[3], p[7], p[6] ], new Point(0, 1, 0), false /* single-sided */, Polygon.SOLID, [0, 255, 0, 0.4] )); // Left scene.shapes["box"].polygons.push(new Polygon( [ p[0], p[4], p[7], p[3] ], new Point(-1, 0, 0), true /* double-sided */, Polygon.SOLID, [255, 255, 0] )); // Right scene.shapes["box"].polygons.push(new Polygon( [ p[1], p[5], p[6], p[2] ], new Point(1, 0, 0), true /* double-sided */, Polygon.SOLID, [0, 255, 255] )); // Create a floor shape and add it to the scene scene.shapes["floor"] = new Shape(); var p = scene.shapes["floor"].points; // for convenience p[0] = new Point(-40, -10, -40); p[1] = new Point(-40, -10, 40); p[2] = new Point( 40, -10, 40); p[3] = new Point( 40, -10, -40); // Floor scene.shapes["floor"].polygons.push(new Polygon( [ p[0], p[1], p[2], p[3] ], new Point(0, 1, 0), false /* single-sided */, Polygon.SOLID, [45, 45, 45] )); setInterval("loop()", 20); } /* -------------------------------------------------------------------- */ </script> <style> body { background-color:black; margin:50px; text-align:center; } </style>
</head> <body onload="load();">
<canvas id="cv" width="400" height="300"></canvas>
</body> </html>
</source>