好看的跟随鼠标滑动的七彩球球特效
2018年10月17日
<!--效果html开始--><div id="container"></div><script type="text/javascript">var Sketch=function(){function e(e){e=n(e||{},l);var t="sketch-"+r++,o=e.hasOwnProperty("canvas"),u=o?e.canvas:document.createElement("canvas");switch(e.type){case m:try{s=u.getContext("webgl",e)}catch(d){}try{s=s||u.getContext("experimental-webgl",e)}catch(d){}if(!s)throw"WebGL not supported";break;case c:try{s=u.getContext("2d",e)}catch(d){}if(!s)throw"Canvas not supported";break;default:u=s=document.createElement("div")}return s.canvas=u,u.className="sketch",o?e.autoresize=!1:(e.container.appendChild(u),e.hasOwnProperty("autoresize")||(e.autoresize=l.autoresize),u.id=t),n(self,g),n(s,e),n(s,p),a(),e.autoresize&&i(),w.push(s),s.autostart&&setTimeout(s.start,0),s}function n(e,n){for(var t in n)e.hasOwnProperty(t)||(e[t]=n[t]);return e}function t(e){function n(e,n){return function(){e.call(n,arguments)}}var t={};for(var o in e)t[o]="function"==typeof e[o]?n(e[o],e):e[o];return t}function o(e,n){e.length=0;for(var t=0,o=n.length;o>t;t++)e[t]=n[t];return e}function a(){function e(e){return M[e]||String.fromCharCode(e)}function n(e){s.mouse.ox=s.mouse.x,s.mouse.oy=s.mouse.y,s.mouse.x=e.x,s.mouse.y=e.y,s.mouse.dx=s.mouse.x-s.mouse.ox,s.mouse.dy=s.mouse.y-s.mouse.oy}function a(e){var n,o=t(e);o.original=e;for(var a=s.canvas,u=0,i=0;a;a=a.offsetParent)u+=a.offsetLeft,i+=a.offsetTop;if(o.touches&&o.touches.length)for(var r,c=o.touches.length-1;c>=0;c--)r=o.touches[c],r.x=r.pageX-u,r.y=r.pageY-i,n=A[c]||r,r.dx=r.x-n.x,r.dy=r.y-n.x,r.ox=n.x,r.oy=n.y,A[c]=t(r);else o.x=o.pageX-u,o.y=o.pageY-i,n=A.mouse||o,o.dx=o.x-n.x,o.dy=o.y-n.y,o.ox=n.x,o.oy=n.y,A.mouse=o;return o}function u(e){e.preventDefault(),e=a(e),o(s.touches,e.touches),n(s.touches[0]),s.touchstart&&s.touchstart(e),s.mousedown&&s.mousedown(e)}function r(e){e=a(e),o(s.touches,e.touches),n(s.touches[0]),s.touchmove&&s.touchmove(e),s.mousemove&&s.mousemove(e)}function c(e){if(e=a(e),e.touches.length)for(var n in A)e.touches[n]||delete A[n];else A={};s.touchend&&s.touchend(e),s.mouseup&&s.mouseup(e)}function m(e){e=a(e),s.mouseover&&s.mouseover(e)}function d(e){e=a(e),s.dragging||(x(s.canvas,"mousemove",h),x(s.canvas,"mouseup",v),y(document,"mousemove",h),y(document,"mouseup",v),s.dragging=!0),o(s.touches,[e]),s.touchstart&&s.touchstart(e),s.mousedown&&s.mousedown(e)}function h(e){e=a(e),n(e),o(s.touches,[e]),s.touchmove&&s.touchmove(e),s.mousemove&&s.mousemove(e)}function f(e){e=a(e),s.mouseout&&s.mouseout(e)}function v(e){e=a(e),s.dragging&&(x(document,"mousemove",h),x(document,"mouseup",v),y(s.canvas,"mousemove",h),y(s.canvas,"mouseup",v),s.dragging=!1),delete A.mouse,s.touchend&&s.touchend(e),s.mouseup&&s.mouseup(e)}function w(e){e=a(e),s.click&&s.click(e)}function l(n){s.keys[e(n.keyCode)]=!0,s.keys[n.keyCode]=!0,s.keydown&&s.keydown(n)}function g(n){s.keys[e(n.keyCode)]=!1,s.keys[n.keyCode]=!1,s.keyup&&s.keyup(n)}var M={8:"BACKSPACE",9:"TAB",13:"ENTER",16:"SHIFT",27:"ESCAPE",32:"SPACE",37:"LEFT",38:"UP",39:"RIGHT",40:"DOWN"};for(var k in M)p.keys[M[k]]=!1;var A={};y(s.canvas,"touchstart",u),y(s.canvas,"touchmove",r),y(s.canvas,"touchend",c),y(s.canvas,"mouseover",m),y(s.canvas,"mousedown",d),y(s.canvas,"mousemove",h),y(s.canvas,"mouseout",f),y(s.canvas,"mouseup",v),y(s.canvas,"click",w),y(document,"keydown",l),y(document,"keyup",g),y(window,"resize",i)}function u(){if(!h){var e=Date.now();s.dt=e-s.now,s.millis+=s.dt,s.now=e,s.update&&s.update(s.dt),s.autoclear&&s.clear(),s.draw&&s.draw(s)}h=++h%s.interval,f=requestAnimationFrame(u)}function i(){if(s.autoresize){var e=s.type===d?s.style:s.canvas;s.fullscreen?(s.height=e.height=window.innerHeight,s.width=e.width=window.innerWidth):(e.height=s.height,e.width=s.width),s.resize&&s.resize()}}var s,r=0,c="canvas",m="web-gl",d="dom",h=0,f=-1,v={},w=[],l={fullscreen:!0,autostart:!0,autoclear:!0,autopause:!0,autoresize:!0,container:document.body,interval:1,type:c},g={PI:Math.PI,TWO_PI:2*Math.PI,HALF_PI:Math.PI/2,QUARTER_PI:Math.PI/4,abs:Math.abs,acos:Math.acos,asin:Math.asin,atan2:Math.atan2,atan:Math.atan,ceil:Math.ceil,cos:Math.cos,exp:Math.exp,floor:Math.floor,log:Math.log,max:Math.max,min:Math.min,pow:Math.pow,round:Math.round,sin:Math.sin,sqrt:Math.sqrt,tan:Math.tan,random:function(e,n){return e&&"number"==typeof e.length&&e.length?e[Math.floor(Math.random()*e.length)]:("number"!=typeof n&&(n=e||1,e=0),e+Math.random()*(n-e))}},p={millis:0,now:0/0,dt:0/0,keys:{},mouse:{x:0,y:0,ox:0,oy:0,dx:0,dy:0},touches:[],initialized:!1,dragging:!1,running:!1,start:function(){s.running||(s.setup&&!s.initialized&&(s.autopause&&(y(window,"focus",s.start),y(window,"blur",s.stop)),s.setup()),s.initialized=!0,s.running=!0,s.now=Date.now(),u())},stop:function(){cancelAnimationFrame(f),s.running=!1},toggle:function(){(s.running?s.stop:s.start)()},clear:function(){s.canvas&&(s.canvas.width=s.canvas.width)},destroy:function(){var e,n,t,o,a,u;w.splice(w.indexOf(s),1),s.stop();for(n in v){for(t=v[n],a=0,u=t.length;u>a;a++)e=t[a],x(e.el,n,e.fn);delete v[n]}s.container.removeChild(s.canvas);for(o in s)s.hasOwnProperty(o)&&delete s[o]}},y=function(){function e(e,n,t){v[n]||(v[n]=[]),v[n].push({el:e,fn:t})}return window.addEventListener?function(n,t,o){n.addEventListener(t,o,!1),e(n,t,o)}:window.attachEvent?function(n,t,o){n.attachEvent("on"+t,o),e(n,t,o)}:function(n,t,o){n["on"+t]=o,e(n,t,o)}}(),x=function(){function e(e,n,t){if(v[n])for(var o,a=v[n].length-1;a>=0;a--)o=v[n][a],o.el===e&&o.fn===t&&v[n].splice(a,1)}return window.removeEventListener?function(n,t,o){n.removeEventListener(t,o,!1),e(n,t,o)}:window.detachEvent?function(n,t,o){n.detachEvent("on"+t,o),e(n,t,o)}:(el["on"+ev]=null,e(el,ev,fn),void 0)}();return{CANVAS:c,WEB_GL:m,DOM:d,instances:w,create:e}}();Date.now||(Date.now=function(){return+new Date}),function(){for(var e=0,n=["ms","moz","webkit","o"],t=0;n.length>t&&!window.requestAnimationFrame;++t)window.requestAnimationFrame=window[n[t]+"RequestAnimationFrame"],window.cancelAnimationFrame=window[n[t]+"CancelAnimationFrame"]||window[n[t]+"CancelRequestAnimationFrame"];window.requestAnimationFrame||(window.requestAnimationFrame=function(n){var t=Date.now(),o=Math.max(0,16-(t-e)),a=window.setTimeout(function(){n(t+o)},o);return e=t+o,a}),window.cancelAnimationFrame||(window.cancelAnimationFrame=function(e){clearTimeout(e)})}();</script><script type="text/javascript" >function Particle( x, y, radius ) { this.init( x, y, radius );}Particle.prototype = { init: function( x, y, radius ) { this.alive = true; this.radius = radius || 10; this.wander = 0.15; this.theta = random( TWO_PI ); this.drag = 0.92; this.color = '#fff'; this.x = x || 0.0; this.y = y || 0.0; this.vx = 0.0; this.vy = 0.0; }, move: function() { this.x += this.vx; this.y += this.vy; this.vx *= this.drag; this.vy *= this.drag; this.theta += random( -0.5, 0.5 ) * this.wander; this.vx += sin( this.theta ) * 0.1; this.vy += cos( this.theta ) * 0.1; this.radius *= 0.96; this.alive = this.radius > 0.5; }, draw: function( ctx ) { ctx.beginPath(); ctx.arc( this.x, this.y, this.radius, 0, TWO_PI ); ctx.fillStyle = this.color; ctx.fill(); }};// ----------------------------------------// Example// ----------------------------------------var MAX_PARTICLES = 280;var COLOURS = [ '#69D2E7', '#A7DBD8', '#E0E4CC', '#F38630', '#FA6900', '#FF4E50', '#F9D423' ];var particles = [];var pool = [];var demo = Sketch.create({ container: document.getElementById( 'container' )});demo.setup = function() { // Set off some initial particles. var i, x, y; for ( i = 0; i < 20; i++ ) { x = ( demo.width * 0.5 ) + random( -100, 100 ); y = ( demo.height * 0.5 ) + random( -100, 100 ); demo.spawn( x, y ); }};demo.spawn = function( x, y ) { if ( particles.length >= MAX_PARTICLES ) pool.push( particles.shift() ); particle = pool.length ? pool.pop() : new Particle(); particle.init( x, y, random( 5, 20 ) ); particle.wander = random( 0.5, 2.0 ); particle.color = random( COLOURS ); particle.drag = random( 0.7, 0.99 );//0.9 0.99 theta = random( TWO_PI ); force = random( 2, 8 ); particle.vx = sin( theta ) * force; particle.vy = cos( theta ) * force; particles.push( particle );}demo.update = function() { var i, particle; for ( i = particles.length - 1; i >= 0; i-- ) { particle = particles[i]; if ( particle.alive ) particle.move(); else pool.push( particles.splice( i, 1 )[0] ); }};demo.draw = function() { demo.globalCompositeOperation = 'lighter'; for ( var i = particles.length - 1; i >= 0; i-- ) { particles[i].draw( demo ); }};demo.mousemove = function() { var particle, theta, force, touch, max, i, j, n; for ( i = 0, n = demo.touches.length; i < n; i++ ) { touch = demo.touches[i], max = random( 1, 4 ); for ( j = 0; j < max; j++ ) demo.spawn( touch.x, touch.y ); }};</script><!--效果html结束--></div>