- From: Ian Hickson <ian@hixie.ch>
- Date: Fri, 14 Jun 2013 17:42:42 +0000 (UTC)
- To: Brian Salomon <bsalomon@chromium.org>
- Cc: whatwg@whatwg.org, Rik Cabanier <cabanier@gmail.com>
On Fri, 14 Jun 2013, Brian Salomon wrote: > > As an implementor, we would prefer the layer approach. This would have > lower overhead in Chromium/Skia. We can make better decisions about > caching and deferred rendering. It also seems like a really handy API > for devs, especially the ability to inherit the graphics state. Would > the spec have anything to say about beginLayer()/endLayer() balancing, > especially with respect to RAF? I have no ojection to adding this to the spec, but right now the spec has a bunch of features that aren't implemented, and there's a long list of other features people want that aren't yet specced. I'm very hesitant to get the spec further and further away from implementations. For example, here are some of the bug numbers for <canvas> feature requests: 11399 <canvas> Locking individual color channels (e.g. drawing to alpha only) 21835 <canvas> Path object should have a way to add paths keeping only the union given a fill rule 21939 <canvas> Path objects would be much more useful if their individual commands (moveTo, lineTo, etc.) could be inspected from JavaScript [...] 8794 <canvas> lineWidth = 'hairline' 11739 <canvas> clearPath() that clears pixels the way clearRect() does, but using a path 9236 <canvas> Detecting the intersection of Path objects 9235 <canvas> perspective transformations 18751 <canvas> a way to get the coordinate of the last point in a path 21346 <canvas> Have ImageBitmap expose height and width attributes (Bugs accessible from https://www.w3.org/Bugs/Public/) There's also the printCallback API proposal from Mozilla: http://lists.w3.org/Archives/Public/public-whatwg-archive/2012Sep/0371.html Adding a parameter to drawImage for sprite sheets to avoid bleeding, proposal from Chrome: http://lists.w3.org/Archives/Public/public-whatwg-archive/2012Dec/0088.html Stroke alignment: http://lists.w3.org/Archives/Public/public-whatwg-archive/2010Jul/0238.html Page flipping instead of double buffering: http://lists.w3.org/Archives/Public/public-whatwg-archive/2013Jan/0073.html Inner shadows: http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2012-November/038079.html Plus, as I mentioned, things in the spec that aren't implemented widely: Right now, the things in the spec that aren't widely implemented are the things that were needed for accessibility (hit regions) and the things that are the basis for some of the most-requested features (Paths). I think before we add more features, it's important that we figure out which browsers want to implement which features, and that we start with the highest priority ones. -- Ian Hickson U+1047E )\._.,--....,'``. fL http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Friday, 14 June 2013 17:43:06 UTC