- From: Glenn Maynard <glenn@zewt.org>
- Date: Thu, 14 Apr 2011 10:22:26 -0400
I forgot that this was all still going to whatwg, instead of public-webgl. We may want to move there. On Thu, Apr 14, 2011 at 12:33 AM, Glenn Maynard <glenn at zewt.org> wrote: > On Wed, Apr 13, 2011 at 9:01 PM, Kenneth Russell <kbr at google.com> > wrote:Return a new object for contextId > > > Adding support for asynchronous initialization of WebGL is a good > > idea, and should be proposed on public_webgl, but this discussion > > should focus solely on improving the specification of the existing > > synchronous initialization path, and its error conditions. > > I only brought it up here because they're related. If an async path > exists, it can affect the design of the sync path as well. > > > > Given that the proposed asynchronous initialization path above uses > > webglcontextcreationerror and provides a status message, I think that > > should continue to be the error reporting mechanism for the current > > initialization path. > > So, the main difference from how it is now would be that getContext would > return an object, even on fatal errors, since WebGL can't return null from > context creation. That seems to work, and it does minimize the number of > things that would need to change for async initialization. It doesn't > distinguish between "permanent" and "recoverable" errors as we discussed > earlier, but that might just be overcomplicating things. (If that's wanted > too, it could be supported by treating preventDefault on the error event the > same as on the lost event, saying "if it becomes possible to create a > context later, I'm prepared for it". > > User code for this is very simple: > > > var gl = canvas.getContext("webgl"); > if (!gl) { > // WebGL is not supported > } else if (gl.isContextLost()) { > // WebGL could not be initialized; the error message can be received > from > // webglcontextcreationerror (or webglcontextlost) > } > > On Wed, Apr 13, 2011 at 10:53 PM, Cedric Vivier <cedricv at neonux.com> > wrote: > > I don't think the added complexity/verbosity provides any advantage > > over my proposal above (for the applications that even desire to show > > additional failure information). > > Is there a scenario I overlooked? > > Another advantage of using webglcontextlost is that, if the context > restoration proposal in the other thread is accepted, you could > preventDefault during it, just as with any other time the event is > received. It would tell the browser "if it ever becomes possible to create > the context in the future, give it to me" (via webglcontextrestored). You > could do that with *creationerror as well, but it would be duplicate logic. > > -- > Glenn Maynard > > -- Glenn Maynard
Received on Thursday, 14 April 2011 07:22:26 UTC