js实现文字放射性走光动画效果代码-html代码-BFW代码库

js实现文字放射性走光动画效果代码

代码语言：html

所属分类：动画

代码描述：js实现文字放射性走光动画效果代码

下面为部分代码预览，完整代码请点击下载或在bfwstudio webide中打开

<!doctype html>
<html>
<head>
<meta charset="utf-8">


<style>
body{
  background: #000;overflow: hidden
}</style>
</head>
<body>

<canvas id="canvas"></canvas>

<script>
var txt = "BFW";
var txtH = 100;
var font = "sans-serif";
var bg = "#000";
var rayColor1 = "#e0f7fa";
var rayColor2 = "#18ffff";
var fade = 1000;

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var cw = canvas.width = window.innerWidth;
var ch = canvas.height = window.innerHeight;

var w2 = cw/2;
var h2 = ch/2;
var pi = Math.PI;
var pi2 = pi*.5;

var txtCanvas = document.createElement("canvas");
var txtCtx = txtCanvas.getContext("2d");
txtCtx.font = txtH + "px " + font;
txtCtx.textBaseline = "middle";
var txtW = Math.floor(txtCtx.measureText(txt).width);
txtCanvas.width = txtW;
txtCanvas.height = txtH*1.5;

var gradient = ctx.createRadialGradient(w2, h2, 0, w2, h2, txtW);
gradient.addColorStop(0, rayColor2);
gradient.addColorStop(1, rayColor1);
ctx.strokeStyle = gradient;

txtCtx.fillStyle = gradient;
txtCtx.font = txtH + "px " + font;
txtCtx.textBaseline = "middle";
txtCtx.fillText(txt,0,txtH*.5);

//dirty adjust for descends
txtH *= 1.5;

var bufferCanvas = document.createElement("canvas");
bufferCanvas.width = txtW;
bufferCanvas.height = txtH;
var buffer = bufferCanvas.getContext("2d");

//text start position
var sx = (cw-txtW)*0.5
var sy = (ch-txtH)*0.5

////generate data
var rays = [];
var txtData = txtCtx.getImageData(0,0,txtW,txtH);
for (var i = 0; i < txtData.data.length; i+=4) {
  var ii = i/4;
  var row = Math.floor(ii/txtW)
  var col = ii%txtW
  var alpha = txtData.data[i+3]
  if(alpha !== 0){
    var c = "rgba("
    c += [txtData.data[i],txtData.data[i+1],txtData.data[i+2], alpha/255 ] 
    c += ")";
    rays.push(new Ray(Math.floor(ii/txtW), ii%txtW, c));  
  }
}

var current = 1;
//st.........完整代码请登录后点击上方下载按钮下载查看