JS implements collision detection method analysis, and js implements Collision Detection

JS implements collision detection method analysis, and js implements Collision Detection

This article describes how to implement Collision Detection in JavaScript. We will share this with you for your reference. The details are as follows:

A simple Collision Detection example is used to check whether div1 is in conflict with div2. When div1 encounters div2, it changes the color of div2.

Take a look at the analysis diagram:

When div1 is active in a region above div2 (t2 ),
When div1 is active in the right line (r2) of div2 in the right area
When div1 is active in a region below div2 (b2 ),
When div1 is active in the left-side (r2) area of div2

In addition to the above four situations, other situations indicate that div1 and div2 have met, and the next interview will complete the test code

HTML section:

<div id="div1"></div><div id="div2"></div>

Css section:

<style>    #div1{      width:100px ;height: 100px;background: green;      position: absolute;    }    #div2{      width:100px ;height: 100px;background: yellow;      position: absolute;left: 300px;top: 200px;z-index: -1;    }</style>

JS section:

<Script> window. onload = function () {var oDiv = document. getElementById ('div1 '); var oDiv2 = document. getElementById ('div2'); var disX = 0; var disY = 0; oDiv. onmousedown = function (ev) {var ev = ev | window. event; disX = ev. clientX-oDiv. offsetLeft; disY = ev. clientY-oDiv. offsetTop; document. onmousemove = function (ev) {var ev = ev | window. event; var t1 = oDiv. offsetTop; var l1 = oDiv. offsetLeft; var r1 = oDiv. offsetLeft + oDiv. offsetWidth; var b1 = oDiv. offsetTop + oDiv. offsetHeight; var t2 = oDiv2.offsetTop; var l2 = oDiv2.offsetLeft; var r2 = oDiv2.offsetLeft + oDiv2.offsetWidth; var b2 = oDiv2.offsetTop + oDiv2.offsetHeight; if (b1 <t2 | l1> r2 | t1> b2 | r1 <l2) {// indicates not met} else {oDiv2.style. background = 'blue';} oDiv. style. left = ev. clientX-disX + 'px '; oDiv. style. top = ev. clientY-disY + 'px';} document. onmouseup = function () {document. onmousemove = null; document. onmouseup = null;} return false; }}</script>