javascript ES6鼠标划入产生水纹波动效果

本文主要是介绍javascript ES6鼠标划入产生水纹波动效果，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

在这里插入图片描述

ES6写了一个水纹效果。还有点计算的问题。直接上代码Copy一下吧。

export  default class Vertex {static BASE_Y = 150;static BASE_R = 10;static  FRICTION = 0.1;//波形抖动后回复到正常状态的速率指数static  DECELERATION = 0.95;static  SPEED_OF_BASE_WAVE = 3;theta = 0;goalY = 0;amp = 0;x;y;constructor(prmID, parent) {this.theta = 360 * prmID / ( parent.NUM - 1);//角度的弧度值。根据NUM值将舞台上分为NUM块，然后将2π的弧度分配给各块，这样舞台上平静的时候正好是一段完整的波形。this.x = prmID * parent.STAGE_W / (parent.NUM - 1);this.y = Vertex.BASE_Y + Vertex.BASE_R * Math.sin(this.theta * Math.PI / 180);}//让波形不断波动的函数，不断更新各点的y坐标updatePos(diffVal) {this.theta += Vertex.SPEED_OF_BASE_WAVE;if (this.theta >= 360) {this.theta -= 360;}this.goalY = Vertex.BASE_Y + Vertex.BASE_R * Math.sin(this.theta * Math.PI / 180);this.goalY += diffVal;this.amp += this.goalY - this.y;this.y += this.amp * Vertex.FRICTION;//y坐标以FRICTION的缓冲速率缓冲到正常状态this.amp *= Vertex.DECELERATION;}
}/*** Created by EricXie on 2019/6/19.*/
import Vertex from "./Vertex.js";
export default class Wave{STAGE_W=800;STAGE_H=300;NUM=800;MOUSE_DIFF_RATIO=1;AUTO_INTERVAL=3000;vertexes=[];mdlPt=[];diffPt=[[],[]];startIndex=[0,0];mouseOldY;mouseNewY;mouseDiff=0;//mouseDiffGoal的缓冲mouseDiffGoal=0;//鼠标拖动后产生的位相差autoTimer;autoDiff=0;//计时器自动生成的位相差mouseY=0;mouseX=0;constructor(){this.canvas=this.createCanvas();this.ctx=this.canvas.getContext("2d");this.init();this.animation();}createCanvas(){if(this.canvas) return this.canvas;let canvas=document.createElement("canvas");Object.assign(canvas.style,{width:"800px",height:"300px",backgroundColor:"#FFFFFF",margin:"auto"});canvas.addEventListener("mousemove",this.mouseHandler.bind(this));return canvas;}mouseHandler(e){this.mouseX=e.clientX;this.mouseY=e.clientY;}appendTo(parent){parent.appendChild(this.canvas);}animation(){requestAnimationFrame(this.animation.bind(this));this.updateMouseDiff();this.updateWave();}init(){for (let i=0; i<this.NUM; i++) {let vertex=new Vertex(i,this);this.vertexes.push(vertex);//中点作成if (i>1) {this.mdlPt.push( {x:(this.vertexes[i-1].x+this.vertexes[i].x)*0.5,y:(this.vertexes[i-1].y+this.vertexes[i].y)*0.5});}//差分this.diffPt[0].push( 0 );this.diffPt[1].push( 0 );}this.mouseNewY=this.mouseY;if (this.mouseNewY<0) {this.mouseNewY=0;} else if (this.mouseNewY > this.STAGE_H) {this.mouseNewY=this.STAGE_H;}this.mouseOldY=this.mouseNewY;setInterval(this.generateAutoWave.bind(this),this.AUTO_INTERVAL);}updateMouseDiff(){this.mouseOldY=this.mouseNewY;this.mouseNewY=this.mouseY;if (this.mouseNewY<0) {this.mouseNewY=0;} else if (this.mouseNewY > this.STAGE_H) {this.mouseNewY=this.STAGE_H;}this.mouseDiffGoal = (this.mouseNewY - this.mouseOldY) * this.MOUSE_DIFF_RATIO;}updateWave(){this.ctx.clearRect(0,0,this.STAGE_W,this.STAGE_H);this.mouseDiff -= (this.mouseDiff - this.mouseDiffGoal)*0.3;this.autoDiff-=this.autoDiff*0.9;//波形自动波动时的速率let mX=this.mouseX;if (mX<0) {mX=0;} else if (mX > this.STAGE_W-2) {mX=this.STAGE_W-2;}this.startIndex[0] = 1+Math.floor( (this.NUM-2) * mX / this.STAGE_W );//startIndex[0]表示波形图上，鼠标拖动的那个点,用Math.floor是//可以取到NUM个点里面x坐标小于当前鼠标x坐标的最大值this.diffPt[0][this.startIndex[0]] -= ( this.diffPt[0][this.startIndex[0]] - this.mouseDiff )*0.99;//自动波this.diffPt[1][this.startIndex[1]] -= ( this.diffPt[1][this.startIndex[1]] - this.autoDiff )*0.99;let d;let i;for ( i=this.startIndex[0]-1; i >=0; i--) {d=this.startIndex[0]-i;if (d>15) {d=15;}this.diffPt[0][i] -= ( this.diffPt[0][i] - this.diffPt[0][i+1] )*(1-0.01*d);}for ( i=this.startIndex[0]+1; i < this.NUM; i++) {d=i-this.startIndex[0];if (d>15) {d=15;}this.diffPt[0][i] -= ( this.diffPt[0][i] - this.diffPt[0][i-1] )*(1-0.01*d);}for ( i=this.startIndex[1]-1; i >=0; i--) {d=this.startIndex[1]-i;if (d>15) {d=15;}this.diffPt[1][i] -= ( this.diffPt[1][i] - this.diffPt[1][i+1] )*(1-0.01*d);}for ( i=this.startIndex[1]+1; i < this.NUM; i++) {d=i-this.startIndex[1];if (d>15) {d=15;}this.diffPt[1][i] -= ( this.diffPt[1][i] - this.diffPt[1][i-1] )*(1-0.01*d);}for ( i=0; i < this.NUM; i++) {this.vertexes[i].updatePos( this.diffPt[0][i]+this.diffPt[1][i]);//更新波形上各点的位相，位相差等于鼠标抖动的和自动产生的，即为diffPt[0][i]+diffPt[1][i]}for ( i=0; i < this.NUM-2; i++) {this.mdlPt[i].y = (this.vertexes[i+1].y + this.vertexes[i+2].y)*0.5;//更新波形图上两点中点的位相，使波形图看起来更流畅}this.drawWave();}drawWave(){this.ctx.fillStyle="#666666";this.ctx.beginPath();this.ctx.moveTo(this.STAGE_W, this.STAGE_H);this.ctx.lineTo(0, this.STAGE_H);this.ctx.lineTo(this.vertexes[0].x, this.vertexes[0].y-50);this.ctx.quadraticCurveTo(this.vertexes[1].x, this.vertexes[1].y-50, this.mdlPt[0].x, this.mdlPt[0].y-50);for (let i=2; i<this.NUM-2; i++) {this.ctx.quadraticCurveTo(this.vertexes[i].x, this.vertexes[i].y-50, this.mdlPt[i-1].x, this.mdlPt[i-1].y-50);}this.ctx.quadraticCurveTo( this.vertexes[this.NUM-2].x, this.vertexes[this.NUM-2].y-50, this.vertexes[this.NUM-1].x, this.vertexes[this.NUM-1].y-50);this.ctx.closePath();this.ctx.fill();}generateAutoWave(){this.autoDiff=200;//自动生成100的位相差this.startIndex[1] = Math.round( Math.random()*(this.NUM-1) );}}

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body><script type="module">import Wave from "./js/wave.js";let wave=new Wave();wave.appendTo(document.body);
</script>
</body>
</html>