On 23/05/2008, at 00:39, Kalle Vahlman wrote:
2008/5/23 Mark Rowe <[EMAIL PROTECTED]>:On 22/05/2008, at 07:24, S Venkata Udai Kiran wrote:Hi all, I was trying to understand how the Layout tests are being done inWebkit. I went through the perl code 'run-webkit-tests' and found thatthe script is using a tool name ImageDiff(WebKit/WebKitBuild/Release/Programs/ImageDiff) .But I could not 'find'that tool in WebKit folder. As I understand that ImageDiff tool is necessary to do a pixel level diff for test images generated.I amlooking at running individual tests using a small shell script rather running all the tests at once. this will help me to know the underlyingthings. Please help.ImageDiff is currently only implemented for Mac and Windows. It's not needed to run the standard regression tests. Pixel test results will differ between platforms and software versions, so there is a lot of manual workinvolved in verifying results when bringing up pixel results on a newplatform. Focusing on text-only and render tree tests would provide muchbetter bang for your buck than pixel test results.That's very true. However, cairo aims at constant quality across output targets and has a similar utility in it's testing suite to verify that: http://gitweb.freedesktop.org/?p=cairo;a=tree;h=4bcc292bc335525f804db83f002692fb42a7b7c7;hb=8efb103600e9c034f8652f495d390d6a4178061e;f=test/pdiff So assuming that the layout code produces identical output on all platforms, testing cairo -backed platforms (gtk, win32...) for pixel-perfectness might make sense.
That Cairo utility doesn't test for pixel-perfectness, it tries to test that there are no perceptible differences. It's an interesting idea and perhaps one that we should explore as an avenue to improve ImageDiff. I don't think it would completely eliminate platform differences, though it should help (eg, different available fonts could lead to different layout, different versions of the libraries used for complex text layout may calculate slightly different metrics, etc.). There would also be a lot of manual work involved in verifying that the initial pixel results are correct (or at least identifying those that are known to be incorrect). The text-only results should be identical across platforms which makes them a lot easier to bring up on a new port.
- Mark
smime.p7s
Description: S/MIME cryptographic signature
_______________________________________________ webkit-dev mailing list [email protected] http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
