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  1. JDK
  2. JDK-8191035

WebView Canvas Graphics2D arc renders incorrectly

    Details

    • Subcomponent:
      web

      Backports

        Description

        We have been attempting to use JavaFx WebView with canvas and 2d Graphics for
        trying to recreate a pie chart, but a simple arc does not draw correctly in WebView,
        Since our application requires use of drawing canvas arcs, we need this fixed.

        Here is codepen which you can use to recreate the problem:

        https://codepen.io/blueShell/pen/MENyRJ

        Here is the same source HTML
        {code}
        <html>
        <head>
          <title></title>
        </head>

        <body>
            <canvas id="myCanvas" width="578" height="250"></canvas>
            <script>
              var canvas = document.getElementById('myCanvas');
        var context = canvas.getContext('2d');
        var x = canvas.width / 2;
        var y = canvas.height / 2;
        var radius = 75;
        var startAngle = 0;
        startAngle = startAngle - (Math.PI / 2.0);
        var ratio = 0.59;
        var endAngle = ratio * Math.PI * 2.0;
        endAngle = endAngle - (Math.PI / 2.0);
        var counterClockwise = false;

        context.beginPath();
        context.arc(x, y, radius, startAngle, endAngle, counterClockwise);
        context.lineWidth = 15;

        // line color
        context.strokeStyle = 'black';
        context.stroke();
            </script>
        </body>
        </html>
        {code}

        Attached are screen shots comparing the arc in different browsers showing WebView is incorrect when compared in Chrome and IE11.

          Attachments

          1. arc.html
            0.7 kB
          2. arc1.html
            0.8 kB
          3. arc-simple-2.diff
            8 kB
          4. webViewArcNotWorking.png
            webViewArcNotWorking.png
            12 kB

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                • Assignee:
                  arajkumar Arunprasad Rajkumar
                  Reporter:
                  shadowbug Shadow Bug
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                  Dates

                  • Created:
                    Updated:
                    Resolved: