| <canvas id="canvas" width="100" height="100"></canvas> |
| <script> |
| var canvas = document.getElementById('canvas'); |
| var ctx = canvas.getContext('2d'); |
| ctx.fillStyle = '#000'; |
| ctx.arc(50, 50, 25, 0, Math.PI * 2, true); |
| ctx.fill(); |
| var tmp_canvas = canvas.cloneNode(); |
| var tmp_ctx = tmp_canvas.getContext('2d'); |
| tmp_ctx.fillStyle = '#0f0'; |
| tmp_ctx.fillRect(25, 25, 50, 50); |
| tmp_ctx.fillStyle = '#000'; |
| tmp_ctx.fillRect(25, 65, 50, 10); |
| ctx.globalCompositeOperation = 'source-in'; |
| ctx.drawImage(tmp_canvas, 0, 0); |
| </script> |