| <!DOCTYPE html> |
| <title>Test using a placeholder canvas as an image source.</title> |
| <script src="../../resources/testharness.js"></script> |
| <script src="../../resources/testharnessreport.js"></script> |
| |
| <script id='myWorker' type='text/worker'> |
| var ctx; |
| self.onmessage = function(msg) { |
| ctx = msg.data.getContext('2d'); |
| ctx.fillStyle = '#0f0'; |
| ctx.fillRect(0, 0, 100, 100); |
| var p = ctx.commit(); |
| |
| p.then(function() { |
| self.postMessage("done"); |
| }); |
| }; |
| </script> |
| |
| <script> |
| var t = async_test("Test that using a placeholder canvas as a source image accesses the image that was committed to the associated OffscreenCanvas in a worker."); |
| var canvas = document.createElement('canvas'); |
| canvas.width = 100; |
| canvas.height = 100; |
| var offscreen = canvas.transferControlToOffscreen(); |
| |
| var blob = new Blob([document.getElementById('myWorker').textContent]); |
| var worker = new Worker(URL.createObjectURL(blob)); |
| worker.postMessage(offscreen, [offscreen]); |
| worker.addEventListener('message', msg => { |
| // the message is a synchronization barrier that guarantees |
| // that the offscreen commit has been processed on the worker thread. |
| verifyImage(canvas, "verify that drawImage works with placeholder canvas as a source."); |
| var testImage = new Image(); |
| testImage.src = canvas.toDataURL(); |
| testImage.onload = function() { |
| verifyImage(canvas, "verify that toDataURL works on placeholder canvas."); |
| canvas.toBlob(blob => { |
| createImageBitmap(blob).then(image => { |
| verifyImage(image, "verify that toBlob works on placeholder canvas."); |
| t.done(); |
| }) |
| }); |
| } |
| }); |
| |
| function verifyImage(image, description) { |
| var testCanvas = document.createElement('canvas'); |
| var testCtx = testCanvas.getContext('2d'); |
| testCtx.drawImage(image, 0, 0); |
| |
| t.step(function() { |
| var pixel = testCtx.getImageData(50, 50, 1, 1).data; |
| assert_array_equals(pixel, [0, 255, 0, 255], description); |
| }); |
| } |
| </script> |
