最近在学习碰撞检测相关的知识,但说实话,写的不咋地。可是由于鄙人学识浅薄,因此以为基本上还行,可是挺追求我完美的,因此想拿出来让大神们批评批评。app
先来看一下效果dom
感受哇,真卡,真难受。由于真原本是正方形因此检测的不是很准确。函数
下面来批评一下这个的代码。性能
if((mover.offsetLeft + mover.offsetWidth >= target.offsetLeft) && (mover.offsetTop + mover.offsetHeight >= target.offsetTop) && (target.offsetLeft + target.offsetWidth >= mover.offsetLeft) && (target.offsetTop + target.offsetHeight >= mover.offsetTop) )
由于碰撞能够分为这四个角度。学习
1.左上角
2.右上角
3.左下角
4.右下角
5.总体图示
只要在那个区域以内就行。this
setInterval(function move(e) { boll.style.left = boll.offsetLeft + (this.N * 10) + 'px'; //改变小球的位置 boll.style.top = boll.offsetTop + (this.T * 10) + 'px'; if(boll.offsetLeft >= sq.offsetWidth - boll.offsetWidth || boll.offsetLeft <= 0 ){ //碰撞左右两边 this.N *= -1; //改变方向(依本身喜爱定义) } if(boll.offsetTop >= sq.offsetHeight - boll.offsetHeight || boll.offsetTop <= 0 ){ //碰撞上下两边 this.T *= -1; //改变方向(依本身喜爱定义) } }.bind(this), 50);
bollArr = [], //存放小球DOM元素,改变方向用 boll = []; //存放小球,检测是否碰撞用
setInterval(function move(e) { for (var i = 0; i < bollArr.length; i ++) { for (var j = i + 1; j < bollArr.length; j ++) { collisionDetection(bollArr[i], bollArr[j], fes[i], fes[j]); } } }, 50);
function Boll() { this.backgroundColor = 'rgba(35, 215, 65, .3)'; //小球颜色 this.left = getRandom(400); //小球位置 this.top = getRandom(400); this.N = 1; //改变小球方向的数(本身能够精肯定义,我就随便定义了) this.T = 1; boll.push(this); }
let sq = document.getElementById('square'), //获取最外面的框 bollArr = [], //小球DOM元素集合 boll = []; //小球实例集合 function Boll() { //构造函数 this.backgroundColor = 'rgba(35, 215, 65, .3)'; this.left = getRandom(400); this.top = getRandom(400); this.N = 1; this.T = 1; boll.push(this); } let boll0 = new Boll(), boll1 = new Boll(), boll2 = new Boll(); Boll.prototype.createBoll = function() { //建立小球 let boll = document.createElement('div'); boll.style.display = 'none'; boll.style.width = '60px'; boll.style.height = '60px'; boll.style.backgroundColor = this.backgroundColor; boll.style.borderRadius = '50%'; boll.style.position = 'absolute'; boll.style.left = this.left + 'px'; boll.style.top = this.top + 'px'; boll.style.display = 'block'; sq.appendChild(boll); bollArr.push(boll); setInterval(function move(e) { //检测是否和外面的框碰撞 boll.style.left = boll.offsetLeft + (this.N * 10) + 'px'; boll.style.top = boll.offsetTop + (this.T * 10) + 'px'; if(boll.offsetLeft >= sq.offsetWidth - boll.offsetWidth || boll.offsetLeft <= 0 ){ this.N *= -1; } if(boll.offsetTop >= sq.offsetHeight - boll.offsetHeight || boll.offsetTop <= 0 ){ this.T *= -1; } }.bind(this), 50); } // 碰撞检测 function collisionDetection(mover, target, boll, boll2) { if((mover.offsetLeft + mover.offsetWidth >= target.offsetLeft) && (mover.offsetTop + mover.offsetHeight >= target.offsetTop) && (target.offsetLeft + target.offsetWidth >= mover.offsetLeft) && (target.offsetTop + target.offsetHeight >= mover.offsetTop) ){ boll.N *= -1; boll.T *= -1; boll2.N *= -1; boll2.T *= -1; } } boll0.createBoll(); boll1.createBoll(); boll2.createBoll(); // 为每两个小球检测是否碰撞 setInterval(function move(e) { for (var i = 0; i < bollArr.length; i ++) { for (var j = i + 1; j < bollArr.length; j ++) { collisionDetection(bollArr[i], bollArr[j], boll[i], boll[j]); } } }, 50);
上面其实有不少很差和bug,但愿看到的大神能批评几句。
由于使用了offset...几乎一直在重排,因此性能不是最好的,但效果基本上实现了。spa