}
},
Sine :{//正弦曲线缓动
easeIn:function (start,alter,curTime,dur) {
return start-(Math.cos(curTime/dur*Math.PI/2)-1)*alter;
},
easeOut:function (start,alter,curTime,dur) {
return start+Math.sin(curTime/dur*Math.PI/2)*alter;
},
easeInOut:function (start,alter,curTime,dur) {
return start-(Math.cos(curTime/dur*Math.PI/2)-1)*alter/2;
}
},
Expo: {//指数曲线缓动
easeIn:function (start,alter,curTime,dur) {
return curTime?(start+alter*Math.pow(2,10*(curTime/dur-1))):start;
},
easeOut:function (start,alter,curTime,dur) {
return (curTime==dur)?(start+alter):(start-(Math.pow(2,-10*curTime/dur)+1)*alter);
},
easeInOut:function (start,alter,curTime,dur) {
if (!curTime) {return start;}
if (curTime==dur) {return start+alter;}
var progress =curTime/dur*2;
if (progress < 1) {
return alter/2*Math.pow(2,10* (progress-1))+start;
} else {
return alter/2* (-Math.pow(2, -10*--progress) + 2) +start;
}
}
},
Circ :{//圆形曲线缓动
easeIn:function (start,alter,curTime,dur) {
return start-alter*Math.sqrt(-Math.pow(curTime/dur,2));
},
easeOut:function (start,alter,curTime,dur) {
return start+alter*Math.sqrt(1-Math.pow(curTime/dur-1));
},
easeInOut:function (start,alter,curTime,dur) {
var progress =curTime/dur*2;
return (progress<1?1-Math.sqrt(1-Math.pow(progress,2)):(Math.sqrt(1 - Math.pow(progress-2,2)) + 1))*alter/2+start;
}
},
Elastic: {//指数衰减的正弦曲线缓动
easeIn:function (start,alter,curTime,dur,extent,cycle) {
if (!curTime) {return start;}
if ((curTime==dur)==1) {return start+alter;}
if (!cycle) {cycle=dur*0.3;}
var s;
if (!extent || extent< Math.abs(alter)) {
extent=alter;
s = cycle/4;
} else {s=cycle/(Math.PI*2)*Math.asin(alter/extent);}
return start-extent*Math.pow(2,10*(curTime/dur-1)) * Math.sin((curTime-dur-s)*(2*Math.PI)/cycle);
},
easeOut:function (start,alter,curTime,dur,extent,cycle) {
if (!curTime) {return start;}
if (curTime==dur) {return start+alter;}
if (!cycle) {cycle=dur*0.3;}
var s;
if (!extent || extent< Math.abs(alter)) {
extent=alter;
s =cycle/4;
} else {s=cycle/(Math.PI*2)*Math.asin(alter/extent);}
return start+alter+extent*Math.pow(2,-curTime/dur*10)*Math.sin((curTime-s)*(2*Math.PI)/cycle);
},
easeInOut:function (start,alter,curTime,dur,extent,cycle) {
if (!curTime) {return start;}
if (curTime==dur) {return start+alter;}
if (!cycle) {cycle=dur*0.45;}
var s;
if (!extent || extent< Math.abs(alter)) {
extent=alter;
s =cycle/4;
} else {s=cycle/(Math.PI*2)*Math.asin(alter/extent);}
var progress = curTime/dur*2;
if (progress<1) {
return start-0.5*extent*Math.pow(2,10*(progress-=1))*Math.sin( (progress*dur-s)*(2*Math.PI)/cycle);
