如何在轮盘赌中插入图像而不是文本数据

Question

我正在使用 this example 创建我自己的轮盘赌，但问题是 'options' 中的 100 美元等价值，我需要使用图像（徽标）。我怎样才能做到这一点？

的用法

<input type="button" value="spin" style="float:left;" id='spin' />
<canvas id="canvas" width="500" height="500"></canvas>

var options = ["0", "", "", "0", "", "00"];
var pattern1, pattern2;
var startAngle = 0;
var arc = Math.PI / (options.length / 2);
var spinTimeout = null;

var spinArcStart = 10;
var spinTime = 0;
var spinTimeTotal = 0;
var canvas = document.getElementById("canvas");
var ctx;

document.getElementById("spin").addEventListener("click", spin);

var img1=new Image();
img1.onload=start;
img1.src="http://oi63.tinypic.com/2n1eyxk.jpg";
var img2=new Image();
img2.onload=start;
img2.src="http://oi63.tinypic.com/2n1eyxk.jpg";
var imgCount=2;
function start(){
  if(--imgCount>0){return;}
  pattern1=ctx.createPattern(img1,'repeat');
  pattern2=ctx.createPattern(img2,'repeat');
  draw();
}


function byte2Hex(n) {
  var nybHexString = "0123456789ABCDEF";
  return String(nybHexString.substr((n >> 4) & 0x0F,1)) + nybHexString.substr(n & 0x0F,1);
}

function RGB2Color(r,g,b) {
    return '#' + byte2Hex(r) + byte2Hex(g) + byte2Hex(b);
}

function getColor(item, maxitem) {
  var phase = 0;
  var center = 128;
  var width = 127;
  var frequency = Math.PI*2/maxitem;

  red   = Math.sin(frequency*item+2+phase) * width + center;
  green = Math.sin(frequency*item+0+phase) * width + center;
  blue  = Math.sin(frequency*item+4+phase) * width + center;

  return RGB2Color(red,green,blue);
}

function drawRouletteWheel() {
  var canvas = document.getElementById("canvas");
  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 Helvetica, Arial';

    for(var i = 0; i < options.length; i++) {
      var angle = startAngle + i * arc;
      //ctx.fillStyle = colors[i];
      ctx.fillStyle = getColor(i, options.length);

      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 = options[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 Helvetica, Arial';
  var text = options[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);
}

drawRouletteWheel();

在示例中使用'context.pattern'不允许执行代码和轮盘。

Answer 1

我使用图像数组 url 代替文本数组，并使用 map 将其转换为图像对象数组，这样我就可以在 canvas 上绘制，并在文本位置正在渲染，使用 drawImage

渲染图像

var options = [
"http://icons.iconarchive.com/icons/froyoshark/enkel/128/Telegram-icon.png", "http://icons.iconarchive.com/icons/froyoshark/enkel/128/Telegram-icon.png", "http://icons.iconarchive.com/icons/froyoshark/enkel/128/Telegram-icon.png", "http://icons.iconarchive.com/icons/froyoshark/enkel/128/Telegram-icon.png", "http://icons.iconarchive.com/icons/froyoshark/enkel/128/Telegram-icon.png", "http://icons.iconarchive.com/icons/froyoshark/enkel/128/Telegram-icon.png"];
var pattern1, pattern2;
var startAngle = 0;
var arc = Math.PI / (options.length / 2);
var spinTimeout = null;

var spinArcStart = 10;
var spinTime = 0;
var spinTimeTotal = 0;
var canvas = document.getElementById("canvas");
var ctx;

options = options.map(x => { 
   var img = new Image();
   img.src = x;
   return img;
});


document.getElementById("spin").addEventListener("click", spin);


function byte2Hex(n) {
  var nybHexString = "0123456789ABCDEF";
  return String(nybHexString.substr((n >> 4) & 0x0F,1)) + nybHexString.substr(n & 0x0F,1);
}

function RGB2Color(r,g,b) {
    return '#' + byte2Hex(r) + byte2Hex(g) + byte2Hex(b);
}

function getColor(item, maxitem) {
  var phase = 0;
  var center = 128;
  var width = 127;
  var frequency = Math.PI*2/maxitem;

  red   = Math.sin(frequency*item+2+phase) * width + center;
  green = Math.sin(frequency*item+0+phase) * width + center;
  blue  = Math.sin(frequency*item+4+phase) * width + center;

  return RGB2Color(red,green,blue);
}

function drawRouletteWheel() {
  var canvas = document.getElementById("canvas");
  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 Helvetica, Arial';

    for(var i = 0; i < options.length; i++) {
      var angle = startAngle + i * arc;
      //ctx.fillStyle = colors[i];
      ctx.fillStyle = getColor(i, options.length);

      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 img = options[i];
       ctx.drawImage(img, 0, 0, 30, 30);
      //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 Helvetica, Arial';
  //var text = options[index]
  var img = options[index];
       ctx.drawImage(img, -img.width/2, 0, 30, 30);
 // 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);
}

drawRouletteWheel();

<input type="button" value="spin" style="float:left;" id='spin' />
<canvas id="canvas" width="500" height="500"></canvas>

如何在轮盘赌中插入图像而不是文本数据

How insert image instead of text-data in roullete wheel

html

javascript

canvas

roulette-wheel-selection