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Re: Comment on Device Orientation API

From: Lars Erik Bolstad <lbolstad@opera.com>
Date: Thu, 01 Mar 2012 11:18:55 +0100
Message-ID: <4F4F4D0F.3010606@opera.com>
To: public-geolocation@w3.org
Hi Martin,

Sounds like we've capped this at a too high level in Opera's 
implementation. We'll adjust that.

Lars Erik

On 29.02.2012 21:40, Doug Turner wrote:
> Hi Martin,
>
> Thanks for your suggestion.  This is an interesting idea, and one
> that was discussed.  The draft states:
>
> The event should fire whenever a significant change in orientation
> occurs. The definition of a significant change in this context is
> left to the implementation. Implementations may also fire the event
> if they have reason to believe that the page does not have
> sufficiently fresh data.
>
> I tend to think that Opera filtering at 4 degrees is a UA bug.  Maybe
> a RFE.  I do not think I want to expose tighter control here to web
> application.  Surely any change to the API allowing such control
> could be veto'ed by the UA.  Opera could still cap their
> notifications at 4 degree changes even though the web application
> asked for something tighter.
>
> It could also be an implementation concern.  I know when I fire lots
> of events, the over all browser performance suffers.  I think UA's
> need some flexibility here to provide the best possible performance.
>
> Thanks again,
>
> Doug Turner
>
>
>
> On Feb 29, 2012, at 6:46 AM, Martin Lechner wrote:
>
>> Dear members of the Geolocation Working Group,
>>
>> I am Martin Lechner, CTO of Wikitude, a member of W3C and developer
>> of the Wikitude World Browser.
>>
>> We are currently developing an augmented reality project on
>> platforms based on the DeviceOrientation API, and do have a comment
>> regarding some specific items in the draft specification.
>>
>> The current specified update rate of the device orientation event
>> is not sufficient for our usecase. Specifically the phrase: “the
>> event should fire whenever a significant change in orientation
>> occurs.” leaves it up to the implementation when exactly to fire an
>> event.
>>
>> We are already seeing different implementation in the prerelease
>> versions of Opera (LAB Opera Mobile) and Mozilla (Aurora). While
>> Mozilla reports events quite frequently (which is preferred by us),
>> Opera matches the specification and reports events only if there is
>> a change of approximately 4 degrees.
>>
>> Our suggestion would be to let the web developer define how
>> accurate the orientation changes should be reported. E.g. like the
>> accuracy modes in Geolocation API. For AR it would be nice to have
>> a high accuracy to achieve more events to get a smoother, more
>> accurate calculation when moving the device.
>>
>> Best regards, Martin Lechner
>>
>> -- - - - Martin Lechner CTO
>>
>> Wikitude GmbH Ginzkeyplatz 11 5020 Salzburg/Austria Phone +43 662
>> 243310 Mobile +43 676 840 856 300
>>
>> http://www.wikitude.com
>>
>>
>>
>
Received on Thursday, 1 March 2012 10:19:29 GMT

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