So are we saying it's impossible to have matching results across all platforms if a test involves any text (in any font)?
I know it's certainly possible to have pixel-results for tests which do not involve text match across all platforms (like SVG or images or css styling, etc.) Or is all this just theory? -eric On Mon, Jun 6, 2011 at 8:09 PM, Hao Zheng <[email protected]> wrote: > Yes, actually in Skia, Chromium/Linux uses a noop gamma implementation > in SkFontHost_gamma_none.cpp; however, if you use a substantial > implementation in SkFontHost_gamma.cpp, there will be much image > mismatch on Chromium/Linux for every font including Ahem. The slight > differences are on font fringe. > And I think if other WebKit is not using Skia at all, there will > surely be even more differences. > > As the gamma implementation on Clank is desired, we should not fix > this bug. Just file the bug to record this difference. > > On Fri, Jun 3, 2011 at 2:30 AM, Tony Chang <[email protected]> wrote: >> Perhaps, but in practice, it's not enough. Here's an ahem pixel test that >> is slightly different on Mac and Chromium Linux: >> http://trac.webkit.org/browser/trunk/LayoutTests/platform/mac/fast/block/basic/010-expected.png >> http://trac.webkit.org/browser/trunk/LayoutTests/platform/chromium-linux/fast/block/basic/010-expected.png >> >> Also, I think it would be hard to tell by examining the HTML if a test uses >> another font. For example, the line height of an empty block might depend >> on the default font that isn't specified (does <pre></pre> render the same >> height on all platforms?). >> On Thu, Jun 2, 2011 at 10:44 AM, Adam Barth <[email protected]> wrote: >>> >>> I thought the whole point of Ahem was to avoid those problems. >>> >>> Adam >>> >>> >>> On Thu, Jun 2, 2011 at 1:29 AM, Hao Zheng <[email protected]> wrote: >>> > Actually, even the same Ahem font will be rendered differently on >>> > different platform, depending on the font drawing library, the >>> > anti-aliasing algorithm, subpixel, tiny float-point calculation diff >>> > on different arch. >>> > >>> > On Thu, Jun 2, 2011 at 3:30 AM, Eric Seidel <[email protected]> wrote: >>> >> I know that Ahem is safe to use across multiple platforms (the font >>> >> metrics >>> >> will be the same). Do we know if there are any other fonts for which >>> >> this >>> >> is true? >>> >> I'd like to make the style-bot yell at people when they use pixel tests >>> >> with >>> >> non-safe fonts. Right now that list would only include ahem. >>> >> -eric >>> >> _______________________________________________ >>> >> webkit-dev mailing list >>> >> [email protected] >>> >> http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev >>> >> >>> >> >>> > _______________________________________________ >>> > webkit-dev mailing list >>> > [email protected] >>> > http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev >>> > >>> _______________________________________________ >>> webkit-dev mailing list >>> [email protected] >>> http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev >> >> > _______________________________________________ > webkit-dev mailing list > [email protected] > http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev > _______________________________________________ webkit-dev mailing list [email protected] http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
