<script type="text/javascript">

var colors = ["#B8D430", "#3AB745", "#029990", "#3501CB","#2E2C75", "#673A7E", "#CC0071", "#F80120","#F35B20", "#FB9A00", "#FFCC00", "#FEF200"];

var restaraunts = ["北京", "上海", "天津", "南京","杭州", "深圳", "武汉", "济南","重庆", "大连", "合肥", "郑洲"];

var startAngle = 0;

var arc = Math.PI / 6;

var spinTimeout = null;

var spinArcStart = 10;

var spinTime = 0;

var spinTimeTotal = 0;

var ctx;

function draw() {

  drawRouletteWheel();

}

function drawRouletteWheel() {

  var canvas = document.getElementById("wheelcanvas");

  if (canvas.getContext) {

      var outsideRadius = 200;

      var textRadius = 160;

      var insideRadius = 125;

      ctx = canvas.getContext("2d");

      ctx.clearRect(0,0,500,500);

      ctx.strokeStyle = "black";

      ctx.lineWidth = 2;

      ctx.font = 'bold 12px sans-serif';

      for(var i = 0; i < 12; i++) {

          var angle = startAngle + i * arc;

          ctx.fillStyle = colors[i];

          ctx.beginPath();

          ctx.arc(250, 250, outsideRadius, angle, angle + arc, false);

          ctx.arc(250, 250, insideRadius, angle + arc, angle, true);

          ctx.stroke();

          ctx.fill();

          ctx.save();

          ctx.shadowOffsetX = -1;

          ctx.shadowOffsetY = -1;

          ctx.shadowBlur    = 0;

          ctx.shadowColor   = "rgb(220,220,220)";

          ctx.fillStyle = "black";

          ctx.translate(250 + Math.cos(angle + arc / 2) * textRadius, 250 + Math.sin(angle + arc / 2) * textRadius);

          ctx.rotate(angle + arc / 2 + Math.PI / 2);

          var text = restaraunts[i];

          ctx.fillText(text, -ctx.measureText(text).width / 2, 0);

          ctx.restore();

          }

          //Arrow

          ctx.fillStyle = "black";

          ctx.beginPath();

          ctx.moveTo(250 - 4, 250 - (outsideRadius + 5));

          ctx.lineTo(250 + 4, 250 - (outsideRadius + 5));

          ctx.lineTo(250 + 4, 250 - (outsideRadius - 5));

          ctx.lineTo(250 + 9, 250 - (outsideRadius - 5));

          ctx.lineTo(250 + 0, 250 - (outsideRadius - 13));

          ctx.lineTo(250 - 9, 250 - (outsideRadius - 5));

          ctx.lineTo(250 - 4, 250 - (outsideRadius - 5));

          ctx.lineTo(250 - 4, 250 - (outsideRadius + 5));

          ctx.fill();

          }

}

function spin() {

    spinAngleStart = Math.random() * 10 + 10;

    spinTime = 0;

    spinTimeTotal = Math.random() * 3 + 4 * 1000;

    rotateWheel();

}

function rotateWheel() {

    spinTime += 30;

    if(spinTime >= spinTimeTotal) {

        stopRotateWheel();

        return;

    }

    var spinAngle = spinAngleStart - easeOut(spinTime, 0, spinAngleStart, spinTimeTotal);

    startAngle += (spinAngle * Math.PI / 180);

    drawRouletteWheel();    spinTimeout = setTimeout('rotateWheel()', 30);

}

function stopRotateWheel() {

    clearTimeout(spinTimeout);

    var degrees = startAngle * 180 / Math.PI + 90;

    var arcd = arc * 180 / Math.PI;

    var index = Math.floor((360 - degrees % 360) / arcd);    ctx.save();

    ctx.font = 'bold 30px sans-serif';

    var text = restaraunts[index]

    ctx.fillText(text, 250 - ctx.measureText(text).width / 2, 250 + 10);    ctx.restore();

}

function easeOut(t, b, c, d) {

    var ts = (t/=d)*t;

    var tc = ts*t;

    return b+c*(tc + -3*ts + 3*t);

}

draw();

</script>