

这次给大家带来JS做出抛物线运动轨迹,JS做出抛物线运动轨迹的注意事项有哪些,下面就是实战案例,一起来看一下。
具体代码如下:
<!doctype html >
<html>
<head>
<meta charset="utf-8"/>
<title>抛物线运动</title>
<style>
.pwx_rect{position:absolute;left:10px;top:300px;background-color:#888;height:50px;width:50px;}
.pwx_hr{border-top:2px solid #ddd;position:absolute;width:98%;left:0px;top:350px;}
</style>
<script>
test = function(){
var rect = document.getElementById("rect");
pwx(rect,60,5); //参数2:抛物线角度,参数3:横向速度每次增加5
}
function pwx(rect,radian,step){
var animate = function(opt){
var cos = Math.cos(opt.radian*Math.PI/180);//邻边比斜边,60度的话等于1/2
var sin = Math.sin(opt.radian*Math.PI/180);//对边比斜边,30度的话等于1/2
var left = opt.rect.offsetLeft;
var top = opt.rect.offsetTop;
if(opt.radian>0){
left+=opt.step;
opt.radian-=1; //角度递减1
var a = left - opt.initLeft;
var c = (a/cos);
var b = (sin*c);
opt.rect.style.left = opt.initLeft+a+"px";
opt.rect.style.top = opt.initTop-b+"px";
setTimeout(function(){
animate(opt);
},10);
}else{
opt.rect.style.left = left+opt.step+"px";
opt.rect.style.top = opt.initTop+"px";
}
}
animate({
step : step,
rect : rect,
radian : radian,
initTop : rect.offsetTop,
initLeft : rect.offsetLeft
});
}
</script>
</head>
<body>
www.gxlcms.com
<input type="button" value="抛物线" onclick="test()"/>
<p class="pwx_rect" id="rect"></p>
<p class="pwx_hr"></p>
</body>
</html>相信看了本文案例你已经掌握了方法,更多精彩请关注Gxl网其它相关文章!
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