彩色圆环旋转的HTML5网页加载特效

2024-09-05 12:19:03

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彩色圆环旋转的HTML5网页加载特效，也就是网页正在加载其它内容的时候显示的一个动画效果，你可不要认为这是一段Flash，其实它是用HTML5和JS代码生成的，和图片丝毫不沾边，你看看效果就明白了。测试的话，IE8就不行了，使用chrome或火狐吧。

<!doctype html><title>无需图片，jQuery+html5实现的超酷loading效果</title><body><script>(function(){	var emptyFn = function(){};	function Sonic(d) {		this.data = d.path || d.data;		this.imageData = [];		this.multiplier = d.multiplier || 1;		this.padding = d.padding || 0;		this.fps = d.fps || 25;		this.stepsPerFrame = ~~d.stepsPerFrame || 1;		this.trailLength = d.trailLength || 1;		this.pointDistance = d.pointDistance || .05;		this.domClass = d.domClass || 'sonic';		this.fillColor = d.fillColor || '#FFF';		this.strokeColor = d.strokeColor || '#FFF';		this.stepMethod = typeof d.step == 'string' ?			stepMethods[d.step] :			d.step || stepMethods.square;		this._setup = d.setup || emptyFn;		this._teardown = d.teardown || emptyFn;		this._preStep = d.preStep || emptyFn;		this.width = d.width;		this.height = d.height;		this.fullWidth = this.width + 2*this.padding;		this.fullHeight = this.height + 2*this.padding;		this.domClass = d.domClass || 'sonic';		this.setup();	}	var argTypes = Sonic.argTypes = {		DIM: 1,		DEGREE: 2,		RADIUS: 3,		OTHER: 0	};	var argSignatures = Sonic.argSignatures = {		arc: [1, 1, 3, 2, 2, 0],		bezier: [1, 1, 1, 1, 1, 1, 1, 1],		line: [1,1,1,1]	};	var pathMethods = Sonic.pathMethods = {		bezier: function(t, p0x, p0y, p1x, p1y, c0x, c0y, c1x, c1y) {					    t = 1-t;		    var i = 1-t,		        x = t*t,		        y = i*i,		        a = x*t,		        b = 3 * x * i,		        c = 3 * t * y,		        d = y * i;		    return [		        a * p0x + b * c0x + c * c1x + d * p1x,		        a * p0y + b * c0y + c * c1y + d * p1y		    ]		},		arc: function(t, cx, cy, radius, start, end) {		    var point = (end - start) * t + start;		    var ret = [		        (Math.cos(point) * radius) + cx,		        (Math.sin(point) * radius) + cy		    ];		    ret.angle = point;		    ret.t = t;		    return ret;		},		line: function(t, sx, sy, ex, ey) {			return [				(ex - sx) * t + sx,				(ey - sy) * t + sy			]		}	};	var stepMethods = Sonic.stepMethods = {				square: function(point, i, f, color, alpha) {			this._.fillRect(point.x - 3, point.y - 3, 6, 6);		},		fader: function(point, i, f, color, alpha) {			this._.beginPath();			if (this._last) {				this._.moveTo(this._last.x, this._last.y);			}			this._.lineTo(point.x, point.y);			this._.closePath();			this._.stroke();			this._last = point;		}	}	Sonic.prototype = {		setup: function() {			var args,				type,				method,				value,				data = this.data;			this.canvas = document.createElement('canvas');			this._ = this.canvas.getContext('2d');			this.canvas.className = this.domClass;			this.canvas.height = this.fullHeight;			this.canvas.width = this.fullWidth;			this.points = [];			for (var i = -1, l = data.length; ++i < l;) {				args = data[i].slice(1);				method = data[i][0];				if (method in argSignatures) for (var a = -1, al = args.length; ++a < al;) {					type = argSignatures[method][a];					value = args[a];					switch (type) {						case argTypes.RADIUS:							value *= this.multiplier;							break;						case argTypes.DIM:							value *= this.multiplier;							value += this.padding;							break;						case argTypes.DEGREE:							value *= Math.PI/180;							break;					};					args[a] = value;				}				args.unshift(0);				for (var r, pd = this.pointDistance, t = pd; t <= 1; t += pd) {										// Avoid crap like 0.15000000000000002					t = Math.round(t*1/pd) / (1/pd);					args[0] = t;					r = pathMethods[method].apply(null, args);					this.points.push({						x: r[0],						y: r[1],						progress: t					});				}			}			this.frame = 0;			//this.prep(this.frame);		},		prep: function(frame) {			if (frame in this.imageData) {				return;			}			this._.clearRect(0, 0, this.fullWidth, this.fullHeight);						var points = this.points,				pointsLength = points.length,				pd = this.pointDistance,				point,				index,				frameD;			this._setup();			for (var i = -1, l = pointsLength*this.trailLength; ++i < l && !this.stopped;) {				index = frame + i;				point = points[index] || points[index - pointsLength];				if (!point) continue;				this.alpha = Math.round(1000*(i/(l-1)))/1000;				this._.globalAlpha = this.alpha;				this._.fillStyle = this.fillColor;				this._.strokeStyle = this.strokeColor;				frameD = frame/(this.points.length-1);				indexD = i/(l-1);				this._preStep(point, indexD, frameD);				this.stepMethod(point, indexD, frameD);			} 			this._teardown();			this.imageData[frame] = (				this._.getImageData(0, 0, this.fullWidth, this.fullWidth)			);			return true;		},		draw: function() {						if (!this.prep(this.frame)) {				this._.clearRect(0, 0, this.fullWidth, this.fullWidth);				this._.putImageData(					this.imageData[this.frame],					0, 0				);			}			this.iterateFrame();		},		iterateFrame: function() {						this.frame += this.stepsPerFrame;			if (this.frame >= this.points.length) {				this.frame = 0;			}		},		play: function() {			this.stopped = false;			var hoc = this;			this.timer = setInterval(function(){				hoc.draw();			}, 1000 / this.fps);		},		stop: function() {			this.stopped = true;			this.timer && clearInterval(this.timer);		}	};	window.Sonic = Sonic;}());var colors = ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'violet']var square = new Sonic({    width: 100,    height: 100,    pointDistance: .005,    trailLength: .9,    stepsPerFrame: 5,    setup: function() {    	this._.lineWidth = 5;    },    step: function(point, index, frame) {		this._.beginPath();		var color, prev, x, y, angle,			radius = 45,			cx = 50,			cy = 50;		angle = Math.PI/180 * (point.progress * 360);		for (var i = -1, l = colors.length; ++i < l;) {			color = colors[i];			prev = this['_' + color];			x = Math.cos(angle) * radius + cx;			y = Math.sin(angle) * radius + cy;			this._.fillStyle = color;			this._.strokeStyle = color;			this._.beginPath();			prev && this._.moveTo(prev.x, prev.y);			this._.lineTo(x, y);			this._.closePath();			this._.stroke();			this['_' + color] = {x:x,y:y};			radius -= 5;		}    },    path: [        ['arc', 100, 100, 90, 0, 360]    ]});square.play();document.body.appendChild(square.canvas);</script> </body></html>

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