| <!DOCTYPE html> |
| <html> |
| <head></head> |
| <body> |
| <canvas id="mycanvas" width="600" height="400"></canvas> |
| <script> |
| var canvas = document.getElementById('mycanvas'); |
| var ctx = canvas.getContext('2d'); |
| |
| ctx.lineWidth = 3; |
| ctx.strokeStyle = 'rgba(0, 0, 0, 0.5)'; |
| |
| // 20 angles. |
| var sweepAngles = [ |
| -123.7, -2.3, -2, -1, -0.3, -0.000001, 0, 0.000001, 0.3, 0.7, |
| 1, 1.3, 1.5, 1.7, 1.99999, 2, 2.00001, 2.3, 4.3, 3934723942837.3 |
| ]; |
| for (var i = 0; i < sweepAngles.length; i++) { |
| sweepAngles[i] = sweepAngles[i] * Math.PI; |
| } |
| |
| var startAngles = [ |
| -1, -0.5, 0, 0.5 |
| ] |
| for (var i = 0; i < startAngles.length; i++) { |
| startAngles[i] = startAngles[i] * Math.PI; |
| } |
| |
| var startAngle = 0; |
| var anticlockwise = false; |
| var sign = 1; |
| for (var i = 0; i < startAngles.length * 2; i++) { |
| if (i == startAngles.length) { |
| anticlockwise = true; |
| sign = -1; |
| } |
| startAngle = startAngles[i % startAngles.length] * sign; |
| ctx.save(); |
| for (var j = 0; j < sweepAngles.length; j++) { |
| ctx.save(); |
| ctx.beginPath(); |
| ctx.moveTo(0, 2); |
| ctx.arc(18, 15, 10, startAngle, startAngle + (sweepAngles[j] * sign), anticlockwise); |
| ctx.lineTo(0, 28); |
| ctx.stroke(); |
| ctx.restore(); |
| ctx.translate(30, 0); |
| } |
| ctx.restore(); |
| ctx.translate(0, 40); |
| } |
| |
| </script> |
| </body> |
| </html> |
| |
