- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Tue, 28 Jun 2011 11:58:50 -0700
- To: Charles McCathieNevile <chaals@opera.com>
- Cc: Richard Schwerdtfeger <schwer@us.ibm.com>, Cameron McCormack <cam@mcc.id.au>, Charles Pritchard <chuck@jumis.com>, Cynthia Shelly <cyns@microsoft.com>, david.bolter@gmail.com, Frank Olivier <Frank.Olivier@microsoft.com>, Mike@w3.org, public-canvas-api@w3.org, public-html@w3.org, public-html-a11y@w3.org
On Mon, Jun 27, 2011 at 4:20 AM, Charles McCathieNevile <chaals@opera.com> wrote: > On Thu, 23 Jun 2011 22:28:32 +0200, Tab Atkins Jr. <jackalmage@gmail.com> > wrote: >> On Thu, Jun 23, 2011 at 12:56 PM, Richard Schwerdtfeger >> <schwer@us.ibm.com> wrote: >>>> So normally, I imagine, hit testing would be done either by using >>>> isPointInPath() or by custom code looking at a mouse event’s x/y values. >>>> I think this proposal doesn’t work with isPointInPath(), though, is that >>>> right? >>>> >>> I think it would but we would need to incorporate Z order and a notion of >>> the last drawn element to compute which element is on top. The user agent >>> would need to manage this. >> >> You are attempting to recreate a retained-mode API in an >> immediate-mode API. Why is "use SVG" not sufficient for this? > > Because people don't - they use canvas instead. If that were not the case, > the whole effort to specify canvas would be solving a theoretical problem. That's not a useful answer. <canvas> is used for lots of things, of which only a subset are better done in a retained-mode API, of which only a subset are reasonably handled by mapping clicks into a DOM node. I elaborated my objection to this approach in a later email. This development thrust seems to be happening without any clear use-cases to address, and with a preference for minimally-invasive edits to the 2d canvas context. These seem very likely to give a bad result that doesn't solve anything well. I don't think we'll come up with a *good* result until we have clear use-cases that we can then solve. ~TJ
Received on Tuesday, 28 June 2011 18:59:38 UTC