Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource

JavaScript

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <html lang="en">
<head>
  <meta charset="UTF-8">
  <title>test</title>
  <style>
    body {
      display: flex;
      flex-flow: column wrap;
      justify-content: center;
      align-items: center;
    }

    #c {
      margin-top: 20px;      
    }
  
    input[type=range]::before {content: attr(min);  color: #000; padding-right: 5px;}
    input[type=range]::after { content: attr(max); color: #000; padding-left: 5px;}
  </style>
</head>
<body>
  <canvas id="c">当前浏览器不支持canvas 请升级!</canvas>
  <input type="range" name="range" min="0" max="100" step="1">
</body>

<script>
canvas = document.getElementById("c");
ctx  = canvas.getContext("2d");
oRange = document.getElementsByName("range")[0];

M = Math;
Sin = M.sin;
Cos = M.cos;
Sqrt = M.sqrt;
Pow = M.pow;
PI = M.PI;
Round = M.round;

oW = canvas.width = 300;
oH = canvas.height = 300;

// 线宽
lineWidth = 2

// 大半径
r = (oW / 2);
cR = r - 8*lineWidth;

ctx.beginPath();

ctx.lineWidth = lineWidth;

// 水波动画初始参数
axisLength = 2*r - 16*lineWidth;  // Sin 图形长度
unit = axisLength / 8; // 波浪宽
range = .2 // 浪幅
nowrange = range;  
xoffset = 8*lineWidth; // x 轴偏移量
data = ~~(oRange.value) / 100;   // 数据量
sp = 0; // 周期偏移量
nowdata = 0;
waveupsp = 0.002; // 水波上涨速度

// 圆动画初始参数
arcStack = [];  // 圆栈
bR = r-8*lineWidth;
soffset = -(PI/2); // 圆动画起始位置
circleLock = true; // 起始动画锁

// 获取圆动画轨迹点集
for(var i = soffset; i< soffset + 2*PI; i+=1/(8*PI)) {
  arcStack.push([
    r + bR * Cos(i),
    r + bR * Sin(i)
  ])
}

cStartPoint = arcStack.shift();  // 圆起始点

ctx.strokeStyle = "#1c86d1";
ctx.moveTo(cStartPoint[0],cStartPoint[1])

render();  // 开始渲染

function drawSine () {
  ctx.beginPath();
  ctx.save();
  var Stack = []; // 记录起始点和终点坐标
  for (var i = xoffset; i<=xoffset + axisLength; i+=20/axisLength) {
    var x = sp + (xoffset + i) / unit;
    var y = Sin(x) * nowrange;

    var dx = i;

    var dy = 2*cR*(1-nowdata) + (r - cR) - (unit * y);
    
    ctx.lineTo(dx, dy);
    Stack.push([dx,dy])
  }

  // 获取初始点和结束点
  var startP = Stack[0]
  var endP = Stack[Stack.length - 1]

  ctx.lineTo(xoffset + axisLength,oW);
  ctx.lineTo(xoffset,oW);
  ctx.lineTo(startP[0], startP[1])
  ctx.fillStyle = "#1c86d1";
  ctx.fill()
  ctx.restore();
}

function drawText () {
  ctx.globalCompositeOperation = 'source-over';

  var size = 0.4*cR;
  ctx.font = 'bold ' + size + 'px Microsoft Yahei';

  txt = (nowdata.toFixed(2)*100).toFixed(0) + '%';

  var fonty = r + size/2;
  var fontx = r - size * 0.8;
  ctx.fillStyle = "rgba(06, 85, 128, 0.8)";
  ctx.fillText(txt, fontx, fonty)
}

function render () {
  ctx.clearRect(0,0,oW,oH);

  if (circleLock) {
    if (arcStack.length) {
      var temp = arcStack.shift();
      ctx.lineTo(temp[0],temp[1])
      ctx.stroke();
    } else {
      circleLock = false;
      ctx.lineTo(cStartPoint[0],cStartPoint[1])
      ctx.stroke();
      arcStack = null;

      ctx.globalCompositeOperation = 'destination-over';
      ctx.beginPath();
      ctx.lineWidth = lineWidth;
      ctx.arc(r,r, bR, 0, 2*PI, 1);

      ctx.beginPath();  
      ctx.save();
      ctx.arc(r,r, r-16*lineWidth, 0, 2*PI, 1);
      ctx.restore()
      ctx.clip();

      ctx.fillStyle = "#1c86d1";

      // 初始拖拽控件
      oRange.addEventListener("change", function () {
        data = ~~(oRange.value) / 100;
        console.log("data="+data)
      },0);
    }
  } else {
    // 开始水波动画
    // 控制波幅
    if (data >= 0.85) {
      if (nowrange > range/4) {
        var t = range * 0.01;
        nowrange -= t;   
      }
    } else if (data <= 0.1) {
      if (nowrange < range*1.5) {
        var t = range * 0.01;
        nowrange += t;   
      }
    } else {
      if (nowrange <= range) {
        var t = range * 0.01;
        nowrange += t;   
      }      

      if (nowrange >= range) {
        var t = range * 0.01;
        nowrange -= t;
      }
    }

    if((data - nowdata) > 0) {
      nowdata += waveupsp;      
    }

    if((data - nowdata) < 0){
      nowdata -= waveupsp
    }

    sp += 0.07;
    drawSine();
    drawText();  
  }
  requestAnimationFrame(render)
}
</script>
              
            
!

CSS

              
                
              
            
!

JS

              
                
              
            
!
999px

Console