| <!DOCTYPE html> |
| <canvas id="canvas" width="1" height="1"></canvas> |
| <script src="../../resources/js-test.js"></script> |
| <script> |
| jsTestIsAsync = true; |
| |
| description("Tests that non-opaque pixels are faithfully preserved in conversions between ImageData and ImageBitmap"); |
| |
| var imageData = new ImageData(new Uint8ClampedArray([12, 34, 56, 64]), 1, 1); |
| var newImageData; |
| createImageBitmap(imageData).then(imageBitmap => { |
| var context = document.getElementById("canvas").getContext("2d"); |
| context.drawImage(imageBitmap, 0, 0); |
| newImageData = context.getImageData(0, 0, 1, 1); |
| |
| // newImageData is not necessary the same as imageData because of |
| // multiplying and dividing by alpha during the round trip, but |
| // they should be close. |
| // The alpha channel should be exactly the same. |
| shouldBeCloseTo("newImageData.data[0]", "imageData.data[0]", 5); |
| shouldBeCloseTo("newImageData.data[1]", "imageData.data[1]", 5); |
| shouldBeCloseTo("newImageData.data[2]", "imageData.data[2]", 5); |
| shouldBe("newImageData.data[3]", "imageData.data[3]"); |
| |
| finishJSTest(); |
| }); |
| </script> |
