view geotemco/lib/excanvas/testcases/stroke-scale-rotate.html @ 30:022310a26cc5 extractapp

extractapp commit
author Zoe Hong <zhong@mpiwg-berlin.mpg.de>
date Thu, 05 Mar 2015 15:09:46 +0100
parents b12c99b7c3f0
children
line wrap: on
line source

<!DOCTYPE html>
<html>
<head>
<title>Stroke Scale</title>
<style>

body {
  text-align: center
}

canvas {
  background: #eee;
}

</style>
<!--[if IE]><script type="text/javascript" src="../excanvas.js"></script><![endif]-->
<script>

// draw a star
function drawStar (ctx, r){
  ctx.save();

  ctx.beginPath();
  ctx.rotate(-Math.PI / 10);
  ctx.scale(r, r);
  ctx.moveTo(1, 0);
  ctx.lineWidth = ctx.lineWidth / r;

  for (var i = 0; i < 9; i++) {
    ctx.rotate(Math.PI / 5);
    if (i % 2 == 0) {
      ctx.lineTo(0.3819653016466596, 0);
    } else {
      ctx.lineTo(1, 0);
    }
  }
  ctx.closePath();
  ctx.fill();
  ctx.stroke();

  ctx.restore();
}

window.onload = function() {
  var ctx = document.getElementById('c').getContext('2d');

  ctx.save();

  ctx.translate(100.5, 100);
  ctx.lineWidth = 1;

  ctx.beginPath();
  ctx.moveTo(0, 0);
  ctx.lineTo(50, 0);
  ctx.scale(1, 2);
  ctx.rotate(Math.PI / 2);
  ctx.lineTo(25, -50)
  ctx.rotate(Math.PI / 2);
  ctx.lineTo(0, -25)
  ctx.scale(1, 2);
  ctx.closePath();
  ctx.stroke();

  ctx.restore();

  ctx.translate(50, 50);

  ctx.fillStyle = 'white';
  ctx.strokeStyle = 'blue';
  drawStar(ctx, 20);
};

</script>
</head>
<body>

<canvas id=c width=500 height=500></canvas>

</body>
</html>