JavaScript+html5 canvas绘制缤纷多彩的三角形效果完整实例

Z时代
2024-01-10
分类：综合

本文实例讲述了JavaScript+html5 canvas绘制缤纷多彩的三角形效果。分享给大家供大家参考，具体如下：

运行效果截图如下：

具体代码如下：


<!DOCTYPE HTML>
<html>
 <head>
  <title>demo</title>
  <style type="text/css">
   body {
    margin:0; padding:0; 
   }
   #canvas {
    width:500px; height:500px; border:3px solid #F2F2F2; box-shadow:0px 0px 25px #494949; margin:0 auto;
    margin-left:200px; margin-top:50px;
   }
  </style>
 </head>
 <body>
  <canvas id="canvas" width="500px" height="500px"></canvas>
  <script type="text/javascript">
   var colorArray = "01234567890ABCDEFabcdef".split("");
   var canvas = document.getElementById("canvas");
   var ctx = canvas.getContext("2d");
   function createTriangle(startPos, r, color) {
    var startX = startPos.x,
     startY = startPos.y;
     ctx.save();
     ctx.strokeStyle = color || "black";
     ctx.beginPath();
     ctx.lineWidth=2;
     ctx.moveTo(startX, startY);
     ctx.lineTo(startX+r*Math.sin(Math.PI/6), startY+r*Math.cos(Math.PI/6));
     ctx.lineTo(startX-r*Math.sin(Math.PI/6), startY+r*Math.cos(Math.PI/6));
     ctx.lineTo(startX, startY);
     ctx.closePath(); 
     ctx.stroke();
     ctx.restore();
   }
   function createColor() {
    var color = "#";
    for(var i=0; i<6; i++) {
     color += colorArray[Math.floor(Math.random()*colorArray.length)];
    }
    return color;
   }
   for(var i=0; i<100; i++) {
    var x = Math.round(Math.random()*500),
     y = Math.round(Math.random()*500),
     color = createColor();
    console.log(color);
    createTriangle({x: x, y: y}, 50, color); 
   }
  </script>
 </body>
</html>