| <html> |
| <head> |
| <script type="text/javascript"> |
| var setupFinished = false; |
| |
| function onLoad() { |
| var canvas = document.createElement('canvas'); |
| canvas.width = 16; |
| canvas.height = 16; |
| document.body.appendChild(canvas); |
| |
| var gl = canvas.getContext('webgl', { preserveDrawingBuffer: false }); |
| if (!gl) { |
| window.domAutomationController.send("FAILED"); |
| return; |
| } |
| |
| // 1. Initial draw & clear (contents_changed_ = true) |
| gl.clearColor(1.0, 0.0, 0.0, 1.0); |
| gl.clear(gl.COLOR_BUFFER_BIT); |
| |
| // 2. Wait for frame presentation so buffer_clear_needed_ = true and contents_changed_ = false. |
| requestAnimationFrame(() => { |
| requestAnimationFrame(() => { |
| // 3. Perform readback. ClearIfComposited clears the buffer and sets buffer_clear_needed_ = false. |
| canvas.toDataURL(); |
| |
| var resultSent = false; |
| document.addEventListener('visibilitychange', () => { |
| if (document.visibilityState === 'hidden' && !resultSent) { |
| resultSent = true; |
| // 4. Perform gl.clear() in background when buffer_clear_needed_ is false. |
| // EnsureBackColorBuffer() must recreate the discarded back buffer. |
| try { |
| gl.clearColor(0.0, 1.0, 0.0, 1.0); |
| gl.clear(gl.COLOR_BUFFER_BIT); |
| if (gl.getError() === gl.NO_ERROR) { |
| window.domAutomationController.send("SUCCESS"); |
| } else { |
| window.domAutomationController.send("FAILED"); |
| } |
| } catch (e) { |
| window.domAutomationController.send("FAILED"); |
| } |
| } |
| }); |
| |
| window.setupFinished = true; |
| }); |
| }); |
| } |
| </script> |
| </head> |
| <body onload="onLoad()"> |
| </body> |
| </html> |
