| <html> |
| <body> |
| <canvas id="canvas" width="600" height="100" ></canvas> |
| <script> |
| var canvas = document.createElement("canvas"); |
| canvas.width = canvas.height = 100; |
| var context = canvas.getContext("2d"); |
| context.fillStyle = 'green'; |
| context.fillRect(0, 0, 100, 100); |
| var canvas2 = document.createElement("canvas"); |
| var context2 = canvas2.getContext("2d"); |
| var drawCanvas = document.getElementById("canvas"); |
| var drawCtx = drawCanvas.getContext("2d"); |
| |
| context2.globalAlpha = 0.0; |
| context2.drawImage(canvas, 0, 0); |
| drawCtx.drawImage(canvas2, 0, 0, 100, 100, 0, 0, 100, 100); |
| |
| context2.globalAlpha = 0.2; |
| context2.drawImage(canvas, 0, 0); |
| drawCtx.drawImage(canvas2, 0, 0, 100, 100, 100, 0, 100, 100); |
| |
| context2.globalAlpha = 0.4; |
| context2.drawImage(canvas, 0, 0); |
| drawCtx.drawImage(canvas2, 0, 0, 100, 100, 200, 0, 100, 100); |
| |
| context2.globalAlpha = 0.6; |
| context2.drawImage(canvas, 0, 0); |
| drawCtx.drawImage(canvas2, 0, 0, 100, 100, 300, 0, 100, 100); |
| |
| context2.globalAlpha = 0.8; |
| context2.drawImage(canvas, 0, 0); |
| drawCtx.drawImage(canvas2, 0, 0, 100, 100, 400, 0, 100, 100); |
| |
| context2.globalAlpha = 1.0; |
| context2.drawImage(canvas, 0, 0); |
| drawCtx.drawImage(canvas2, 0, 0, 100, 100, 500, 0, 100, 100); |
| </script> |
| </body> |
| </html> |
