Canvas/32_canvas_使用图片.html

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <title>Page Title</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
</head>

<body>
  <canvas id="myCanvas" style="border:1px solid red;">
    当前浏览器不支持canvas，请更换浏览器后再试
  </canvas>
  <script>
    window.onload = function () {
      var canvas = document.getElementById('myCanvas')

      canvas.width = 800
      canvas.height = 800

      var ctx = canvas.getContext('2d')

      // createPattern(img|canvas|video,repeat) createPattern可以使用一张图片或另一个canvas和video来做图形

      var img = new Image()
      img.src = 'http://images.cpooo.com/files/201004/product/233/1271300511.jpg.small.jpg'
      img.onload = function () {
        var pat = ctx.createPattern(img, 'no-repeat')
        ctx.fillStyle = pat
        ctx.fillRect(0, 0, 800, 800)
      }
    }
  </script>
</body>

</html>