html5 canvas五角形星型结构粒子动画特效

html5 canvas五角形星型结构粒子动画特效，红蓝两色的“小蝌蚪”围绕着五角形边框游动的动画效果。

分类：html5 > canvas 难易：中级

查看演示下载资源下载积分： 20 积分

js代码

<script src="js/p5.min.js"></script>
<script src="js/p5.dom.min.js"></script>
<script src="js/p5.sound.min.js"></script>
<script>
var blobs=[];
var numBlobs=200;
 
function setup() {
  createCanvas(windowWidth, windowHeight);
  for(var i=0; i<numBlobs; i++){
    blobs.push(new Blob(random(TWO_PI),height/4));
  }
}
 
function draw() {
  background(50,100);
  blobs.forEach(function(blob){
    blob.show(width/2, height/2);
  });
}
 
function Blob(a,r) {
  var rotSteps=random(300,700);
  var aInc=PI/rotSteps;
  var aWobbleInc=TWO_PI/(rotSteps/5);
  var aWobblePhase=random(PI/4);
  var aWobble=0;
  var rWobble=random(r/2, r/4);
  var trail=[];
  var trailMax=8;
  var dir=random(10)<5?-1:1;
   
  this.show=function(x,y){
    noStroke();
    if(dir>0){
      fill(50,100,255,100);
    } else {
      fill(255,100,120,100);
    }
    push();
    translate(x,y);
    rotate(-PI/6);
    var rNow=r+sin(a*5+(aWobblePhase*noise(frameCount/50)*5))*(r/5+rWobble*noise(0.5+frameCount/50));
    var xNow=cos(a)*rNow;
    var yNow=sin(a)*rNow;
    trail.push({x:xNow, y:yNow});
    if(trail.length>trailMax){
      trail.shift();
    }
    // ellipse(0,rNow,10);
    ellipse(xNow,yNow,height/50);
    trail.forEach(function(posThen,i){
      fill(255,i*130/trailMax);
      noStroke();
      ellipse(posThen.x, posThen.y,i*(height/150)/trailMax);
    });
    fill(255);
    ellipse(xNow,yNow,height/250);
    pop();
    a+=aInc*dir;
    aWobble+=aWobbleInc;
  };
}</script>