按轨迹周期运动
一、水平方向上的反复运动
例如：
水平宽度：50px
小球直径：6px
html结构：
<div id="line" class="line">
<div id="point" class="point" >
</div>
</div>
css样式：
.line{position: relative;width: 100px;height: 100px;border-bottom: 1px solid red;left: 100px;top: 100px;}
.point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
js代码：
var point = document.getElementById("point");
var line = document.getElementById("line");
var i = 0, j = 0;
var b = false;
setInterval(function () {
if (i < line.offsetWidth && false == b) {
i++;
point.style.left = 47 - 50 + i + "px";
point.style.top = 47 + 50 + "px";
}
if (contline.offsetWidth == i) { b = true; }
if (i > 0 && true == b) {
i--;
point.style.left = 47 - 50 + i + "px";
point.style.top = 47 + 50 + "px";
}
if (0 == i) {
b = false;
}
}, 60);
View Code
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2 <html xmlns="http://www.w3.org/1999/xhtml">
3 <head>
4 <title>水平周期运动</title>
5 <style type="text/css">
6 .line{position: relative;width: 100px;height: 100px;border-bottom: 1px solid red;left: 100px;top: 100px;}
7 .point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
8 </style>
9 <script type="text/javascript">
10 window.onload = function () {
11 var point = document.getElementById("point");
12 var line = document.getElementById("line");
13 var i = 0, j = 0;
14 var b = false;
15 setInterval(function () {
16 if (i < line.offsetWidth && false == b) {
17 i++;
18 point.style.left = 47 - 50 + i + "px";
19 point.style.top = 47 + 50 + "px";
20 }
21 if (contline.offsetWidth == i) {
22 b = true;
23 }
24 if (i > 0 && true == b) {
25 i--;
26 point.style.left = 47 - 50 + i + "px";
27 point.style.top = 47 + 50 + "px";
28 }
29 if (0 == i) {
30 b = false;
31 }
32 }, 60);
33 }
34 </script>
35 </head>
36 <body>
37 <div id="line" class="line">
38 <div id="point" class="point">
39 </div>
40 </div>
41 </body>
42 </html>
二、按长方形（正方形）周长运动
长方形的长和宽分别是150px和100px
小球直径：6px
html结构：
<div id="rectangle" class="rectangle">
<div id="point" class="point">
</div>
</div>
css样式：
.rectangle{position: relative;width: 150px;height: 100px;border: 1px solid red;left: 100px;top: 100px;}
.point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
js代码：
var point = document.getElementById("point");
var rectangle = document.getElementById("rectangle");
var i = 0, j = 0;
setInterval(function () {
if (i < rectangle.offsetWidth && 0 == j) {
i++;
point.style.left = 47 - 50 + i + "px";
point.style.top = 47 - 50 + j + "px";
}
else if (rectangle.offsetWidth == i && j < rectangle.offsetHeight) {
j++;
point.style.left = 47 - 50 + i + "px";
point.style.top = 47 - 50 + j + "px";
}
else if (i > 0 && rectangle.offsetHeight == j) {
i--;
point.style.left = 47 - 50 + i + "px";
point.style.top = 47 - 50 + j + "px";
}
else {
j--;
point.style.left = 47 - 50 + i + "px";
point.style.top = 47 - 50 + j + "px";
}
}, 60);
View Code
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2 <html xmlns="http://www.w3.org/1999/xhtml">
3 <head>
4 <title>水平周期运动</title>
5 <style type="text/css">
6 .rectangle{position: relative;width: 150px;height: 100px;border: 1px solid red;left: 100px;top: 100px;}
7 .point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
8 </style>
9 <script type="text/javascript">
10 window.onload = function () {
11 var point = document.getElementById("point");
12 var rectangle = document.getElementById("rectangle");
13 var i = 0, j = 0;
14 setInterval(function () {
15 if (i < rectangle.offsetWidth && 0 == j) {
16 i++;
17 point.style.left = 47 - 50 + i + "px";
18 point.style.top = 47 - 50 + j + "px";
19 }
20
21 else if (rectangle.offsetWidth == i && j < rectangle.offsetHeight) {
22 j++;
23 point.style.left = 47 - 50 + i + "px";
24 point.style.top = 47 - 50 + j + "px";
25 }
26 else if (i > 0 && rectangle.offsetHeight == j) {
27 i--;
28 point.style.left = 47 - 50 + i + "px";
29 point.style.top = 47 - 50 + j + "px";
30 }
31 else {
32 j--;
33 point.style.left = 47 - 50 + i + "px";
34 point.style.top = 47 - 50 + j + "px";
35 }
36 }, 60);
37 }
38 </script>
39 </head>
40 <body>
41 <div id="rectangle" class="rectangle">
42 <div id="point" class="point">
43 </div>
44 </div>
45 </body>
46 </html>
三、按圆形周长运动 2∏R
圆形直径：100px
小球直径：6px
html结构：
<div class="circle">
<div id="point" class="point">
</div>
</div>
css样式：
.circle{position: relative;width: 100px;height: 100px;border: 1px solid red;left: 100px;top: 100px;border-radius: 50px;}
.point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
js代码：
var point = document.getElementById("point");
var i = 0;
setInterval(function () {
if (360 == i) {
i = 0;
point.style.left = 47 + 50 * Math.cos(0 * 2 * Math.PI / 360) + "px";
point.style.top = 47 + 50 * Math.sin(0 * 2 * Math.PI / 360) + "px";
}
else {
i++;
point.style.left = 47 + 50 * Math.cos(i * 2 * Math.PI / 360) + "px";
point.style.top = 47 + 50 * Math.sin(i * 2 * Math.PI / 360) + "px";
}
}, 60);
View Code
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2 <html xmlns="http://www.w3.org/1999/xhtml">
3 <head>
4 <title>水平周期运动</title>
5 <style type="text/css">
6 .circle{position: relative;width: 100px;height: 100px;border: 1px solid red;left: 100px;top: 100px;border-radius: 50px;}
7 .point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
8 </style>
9 <script type="text/javascript">
10 window.onload = function () {
11 var point = document.getElementById("point");
12 var i = 0;
13 setInterval(function () {
14 if (360 == i) {
15 i = 0;
16 point.style.left = 47 + 50 * Math.cos(0 * 2 * Math.PI / 360) + "px";
17 point.style.top = 47 + 50 * Math.sin(0 * 2 * Math.PI / 360) + "px";
18 }
19 else {
20 i++;
21 point.style.left = 47 + 50 * Math.cos(i * 2 * Math.PI / 360) + "px";
22 point.style.top = 47 + 50 * Math.sin(i * 2 * Math.PI / 360) + "px";
23 }
24 }, 60);
25 }
26 </script>
27 </head>
28 <body>
29 <div class="circle">
30 <div id="point" class="point">
31 </div>
32 </div>
33 </body>
34 </html>
四、椭圆周长运动 ∏（a+b）
椭圆长半径：100px、短半径：50px
小球直径：6px
html结构：
<div class="oval">
<div id="point" class="point">
</div>
</div>
css样式：
.oval{position: relative;width: 200px;height: 100px;border: 1px solid red;left: 100px;top: 100px;border-radius: 100px/50px;}
.point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
js代码：
var point = document.getElementById("point");
var i = 0;
setInterval(function () {
if (360 == i) {
i = 0;
point.style.left = 97 + 100 * Math.cos(0 * 2 * Math.PI / 360) + "px";
point.style.top = 47 + 50 * Math.sin(0 * 2 * Math.PI / 360) + "px";
}
else {
i++;
point.style.left = 97 + 100 * Math.cos(i * 2 * Math.PI / 360) + "px";
point.style.top = 47 + 50 * Math.sin(i * 2 * Math.PI / 360) + "px";
}
}, 60);
View Code
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2 <html xmlns="http://www.w3.org/1999/xhtml">
3 <head>
4 <title>水平周期运动</title>
5 <style type="text/css">
6 .oval{position: relative;width: 200px;height: 100px;border: 1px solid red;left: 100px;top: 100px;border-radius: 100px/50px;}
7 .point{width: 6px;height: 6px;background-color: Red;position: absolute;left: 47px;top: 47px;border-radius: 3px;}
8 </style>
9 <script type="text/javascript">
10 window.onload = function () {
11 var point = document.getElementById("point");
12 var i = 0;
13 setInterval(function () {
14 if (360 == i) {
15 i = 0;
16 point.style.left = 97 + 100 * Math.cos(0 * 2 * Math.PI / 360) + "px";
17 point.style.top = 47 + 50 * Math.sin(0 * 2 * Math.PI / 360) + "px";
18 }
19 else {
20 i++;
21 point.style.left = 97 + 100 * Math.cos(i * 2 * Math.PI / 360) + "px";
22 point.style.top = 47 + 50 * Math.sin(i * 2 * Math.PI / 360) + "px";
23 }
24 }, 60);
25 }
26 </script>
27 </head>
28 <body>
29 <div class="oval">
30 <div id="point" class="point">
31 </div>
32 </div>
33 </body>
34 </html>
