September 2011 - webkit-dev - lists.webkit.org

Is it OK to remove Frame::setIsDisconnected() and isDisconnected() ?
by Sverrir Á. Berg 09 Apr '12

09 Apr '12

Working on a change in FrameTree and noticed that the checks in top() and parent() for 'checkForDisconnectedFrame' rely on a flag in Frame that as far as I can tell is never set.So my naive question is: Can I remove the corresponding code from Frame and FrameTree? If not I would like if somebody could explain how they are used so I don't break anything with my change. More detail: * My search for calls to Frame::setIsDisconnected reveals no callers in WebKit, Chromium or Google code search. * This functionality is disjoint from Frame::disconnectOwnerElement(). Thanks, Sverrir

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new APIs for strokes with dash in Canvas
by Young Han Lee 28 Mar '12

28 Mar '12

Hi all, I have a patch to add webkitLineDash and webkitLineDashOffset APIs on CanvasRenderingContext2D on https://bugs.webkit.org/show_bug.cgi?id=63933 The purpose of these APIs is to support for strokes with dash in Canvas. Although the API is not specified in the HTML Canvas specification yet, I believe it would be great to support the API. As Dirk said in the above bug, Mozilla already implemented the APIs named mozDash and mozDashOffset[1], and there seems to be many needs for the API. Some people even implemented their own javascript functions to draw strokes with dash in Canvas[2,3]. As GraphicsContext already have an interface for strokes with dash, setLineDash, all we have to do is exposing it to the JS level. So the syntax and meaning of the new APIs is the same with the arguments of the setLineDash. webkitLineDash is an array of float, and webkitLineDashOffset is a float. I uploaded a patch for JSC first. After the patch is landed, I will make a follow-up patch for V8. Any thought? [1] https://bugzilla.mozilla.org/show_bug.cgi?id=662038 [2] http://davidowens.wordpress.com/2010/09/07/html-5-canvas-and-dashed-lines/ [3] http://stackoverflow.com/questions/7352769/dashed-curves-on-html5-canvas-be…

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Throwing SECURITY_ERR on cross-origin window.location property accesses
by Mihai Parparita 27 Mar '12

27 Mar '12

I was wondering if it would be a reasonable change to make accessing location.href (and other location properties) throw SECURITY_ERR when accessed across origins (https://webkit.org/b/43504) This initially was reported on the Chrome side (http://crbug.com/17325) but it looks like neither the JSC nor V8 bindings do this, so fixing it across the board seemed reasonable. >From my investigations, it looks like IE and Gecko both throw an exception in this case, and the HTML5 spec mentions it too ( http://www.whatwg.org/specs/web-apps/current-work/multipage/history.html#se… ). I realize that we're cautious around the access checks for security reasons (based on changes like https://trac.webkit.org/changeset/48619) but this seems safe since 1) we were returning control to the script at that point anyway 2) we already throw exceptions in some cases in that code: https://trac.webkit.org/browser/trunk/WebCore/bindings/js/JSLocationCustom.… Thanks, Mihai

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New Feature - Resource Timing
by James Simonsen 22 Mar '12

22 Mar '12

Hello webkit-dev, The W3C Performance WG has been working on a Resource Timing spec. The spec is starting to stabilize and we'd like to start landing it in WebKit too. Resource Timing is a follow up to Navigation Timing, which is already in WebKit. Resource Timing allows site developers to collect detailed network timing information for the subresources they load. The data is exposed through the window.performance namespace and we expect developers to ping this information back to the server with their other analytics data. For security reasons, the spec limits the detailed information to same-origin resources, but there is also a provision for a CORS-like header to allow cross-origin resource timing. Resource Timing will be behind ENABLE(WEB_TIMING) since it relies on some of the same infrastructure as Navigation Timing. We can add an additional ENABLE to keep Resource Timing separate from Navigation Timing if that's desired. The current draft of the Resource Timing API is here: http://w3c-test.org/webperf/specs/ResourceTiming/ A meta-bug to track the necessary work is here: https://bugs.webkit.org/show_bug.cgi?id=61138 Please post any feedback. Thanks! James

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Accelerated 2D Tesselation Implementation
by Chris Marrin 03 Mar '12

03 Mar '12

Hi Ken, It would help me, and I think many others, if we could have a discussion of how exactly your tessellation logic works and what it is intended to do. For instance, is the algorithm you're using based on Loop-Blinn? I'm a bit familiar with that algorithm and some of the problems it has with rendering this type of geometry. For instance, there are typically anti-aliasing artifacts at the points where the interior triangles touch the edges. These are described in section 5.1 of the paper and the authors added additional (and not well described) logic to solve the problem. If you could describe your algorithm a bit and show some expected results with typical cases, that would be really helpful. For those not familiar with Loop-Blinn, here is a link to their original paper, presented at Siggraph 2005: Resolution Independent Curve Rendering using Programmable Graphics ... It's a great algorithm for rendering resolution independent 2D objects using the GPU. It has potential to render both 2D shapes (as used in Canvas and SVG) and text glyphs. It's advantage is that once you generate the triangles for the shape, you can render the shape at any resolution. It's disadvantage is that the triangle generation is quite expensive, so mutating shapes can potentially be slower than a simpler resolution dependent tessellation. ----- ~Chris cmarrin(a)apple.com

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It's time to remove the Haiku port
by Adam Barth 04 Nov '11

04 Nov '11

On April 9, 2010, I wrote an email to webkit-dev asking if it was time to remove the Haiku port: http://old.nabble.com/Archiving-the-Haiku-port--(was-WebKit2-and-all-that-j… At the time, the port appeared inactive. Stephan Assmus and Maxime Simon wrote that they planned to continue development of the port. As far as I can tell, neither of them have contributed a patch to WebKit since May 3, 2010. http://trac.webkit.org/search?q=superstippi&changeset=on http://trac.webkit.org/search?q=maxime&changeset=on In the past year, http://trac.webkit.org/log/trunk/Source/WebKit/haiku and http://trac.webkit.org/log/trunk/Source/WebCore/platform/haiku have been modified 70 times by non-Haiku contributors and zero times by Haiku contributors. As part of our effort to reduce complexity in WebKit, I believe it is now time to remove the Haiku port. Adam

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Starting implementation on W3C Filter Effects
by Dean Jackson 04 Nov '11

04 Nov '11

Dirk (known in these parts as krit) reminded me that I had not emailed webkit-dev about the plans to start an implementation of W3C's new Filter Effects specification. https://dvcs.w3.org/hg/FXTF/raw-file/tip/filters/publish/Filters.html The quick summary is that this exposes the 'filter' property from SVG to everything in CSS, and adds some shorthands for common effects so people don't have to write XML in order to do something like a blur or sepia effect. The spec has received a fair amount of input from the CSS and SVG working groups, and particularly from Apple, Google, Mozilla, Opera and Adobe. Here's the tracking bugzilla: https://bugs.webkit.org/show_bug.cgi?id=68469 It will be protected by the existing ENABLE(FILTERS), unless someone has a good reason why this should be a new enabled feature name. The implementation plan that I have in mind is: - start with '-webkit-filter' only for HTML elements that supports something similar to the existing 'filter' - implement more of the spec, including the shorthands - expose '-webkit-filter' to SVG, but only if the existing 'filter' property is not set - wait for the spec to progress, then drop the prefix In parallel we'll also be looking at animation of these effects, plus hardware acceleration (open questions to how: OpenCL? Graphics3D? Core Image where available?) Dean

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DumpRenderTree for the EFL port :)
by Leandro Pereira 04 Nov '11

04 Nov '11

Hey, At last, the EFL port of WebKit got a DumpRenderTree implementation! We're still working on ironing out a lot of bugs found by some of the LayoutTests, but the DRT (and ImageDiff) code has been submitted to Bugzilla. It would be awesome if anyone could help reviewing these patches. DumpRenderTree patches: https://bugs.webkit.org/show_bug.cgi?id=62034 https://bugs.webkit.org/show_bug.cgi?id=61974 https://bugs.webkit.org/show_bug.cgi?id=61962 https://bugs.webkit.org/show_bug.cgi?id=61958 ImageDiff patch: https://bugs.webkit.org/show_bug.cgi?id=61942 Thanks, Leandro

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Committing EFL baselines
by Leandro Pereira 19 Oct '11

19 Oct '11

Hi. What's the preferred way to commit a ton of baselines for a port that currently has none? On our internal EFL tree, there is about 125MB of baselines for both pixel and text tests. Unfortunately we were unable to share our baselines with similar ports, due to slight differences in results. This is pretty much unreviewable, so I pretend to commit this directly, in batches (one commit per toplevel directory in LayoutTests/platform/efl) in the next weeks. Any objections or suggestions? Cheers, Leandro

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Mouse Lock API
by Vincent Scheib 14 Oct '11

14 Oct '11

A Mouse Lock API has been under discussion on the W3 public-webapps list "Mouse Lock"(1) and earlier "Mouse Capture for Canvas"(2). The primary goal is to enable use cases such as first person perspective 3D applications. This is done by providing scripted access to mouse movement data while locking the target of mouse events to a single element and removing the cursor from view. I have been working to formalize the discussions into a draft specification: http://goo.gl/9G8pd, and have a work in progress prototype for WebKit | Chrome. I will publish a WIP patch when it is ready for more eyes. It will be developed behind a compile (and runtime) time flag. I'd like to invite any specification discussion to the Mouse Lock thread (1), and WebKit implementation discussion here. Cheers, -Vince -- 1. http://lists.w3.org/Archives/Public/public-webapps/2011JulSep/thread.html#m… 2. http://lists.w3.org/Archives/Public/public-webapps/2011JanMar/thread.html#m… W3 issue: http://www.w3.org/Bugs/Public/show_bug.cgi?id=9557 Firefox issue: https://bugzilla.mozilla.org/show_bug.cgi?id=633602 Chrome issue: http://code.google.com/p/chromium/issues/detail?id=72754

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