自己做了碰撞检测的封装,先看下实例demo,在看封装
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>碰撞检测</title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
#divA,#divB{
width: 200px;
height: 200px;
background-color: purple;
font-size: 50px;
line-height: 200px;
text-align: center;
position: absolute;
color: #fff;
}
#divA{
left: 30px;
top: 30px;
z-index: 5;
}
#divB{
left: 300px;
top: 300px;
}
</style>
</head>
<body>
<div id="divA">A</div>
<div id="divB">B</div>
</body>
<script type="text/javascript">
var divA = document.getElementById("divA");
var divB = document.getElementById("divB");
divA.onmousedown = function (e) {
var event1 = window.event || e;
var startX = event1.clientX;
var startY = event1.clientY;
document.onmousemove = function (j) {
var event2 = window.event || j;
var endX = event2.clientX;
var endY = event2.clientY;
divA.style.left = divA.offsetLeft (endX - startX) "px";
divA.style.top = divA.offsetTop (endY - startY) "px";
startX = endX;
startY = endY;
if (isCrash(divA,divB) == true) {
divA.style.backgroundColor = "red";
} else{
divA.style.backgroundColor = "purple";
};
}
}
divA.onmouseup = function () {
document.onmousemove = null;
}
function isCrash (obj1,obj2) {
var boolCrash = true;
var left1 = obj1.offsetLeft;
var right1 = obj1.offsetLeft obj1.offsetWidth;
var top1 = obj1.offsetTop;
var bottom1 = obj1.offsetTop obj1.offsetHeight;
var left2 = obj2.offsetLeft;
var right2 = obj2.offsetLeft obj2.offsetWidth;
var top2 = obj2.offsetTop;
var bottom2 = obj2.offsetTop obj2.offsetHeight;
if (right1 > left2 && left1 < right2 && bottom1 > top2 && top1 < bottom2) {
boolCrash = true;
} else{
boolCrash = false;
}
return boolCrash;
}
</script>
</html>
函数封装
function isCrash (obj1,obj2) {
var boolCrash = true;//假设true为碰撞
var left1 = obj1.offsetLeft;
var right1 = obj1.offsetLeft obj1.offsetWidth;
var top1 = obj1.offsetTop;
var bottom1 = obj1.offsetTop obj1.offsetHeight;
var left2 = obj2.offsetLeft;
var right2 = obj2.offsetLeft obj2.offsetWidth;
var top2 = obj2.offsetTop;
var bottom2 = obj2.offsetTop obj2.offsetHeight;
if (right1 > left2 && left1 < right2 && bottom1 > top2 && top1 < bottom2) {
boolCrash = true;
} else{
boolCrash = false;
}
return boolCrash;
}