find a sound emitter's location relative to the user

> On Wed, Oct 29, 2008 at 6:25 PM, Brad Fuller <[hidden email]> wrote:
>> I understand that OpenAL is used. How does the system take care of
>> sound emitters that the user's position to the sound emitters? Is
>> there a way that I can obtain the x,y,z position of a sound emitter
>> relative to the user's position?
>
> Perhaps I'm not clear, since I have a typo in the first sentence, and
> that's why there were no answers.
> Or, maybe it's a question that has been answered many times and I just
> can't find it in the archives.
>  Let me try again.
>
> How can I find the location (in x,y,z) of an object relative to the
> user's position?

> Brad Fuller wrote:
>>
>> On Wed, Oct 29, 2008 at 6:25 PM, Brad Fuller <[hidden email]>
>> wrote:
>>>
>>> I understand that OpenAL is used. How does the system take care of
>>> sound emitters that the user's position to the sound emitters? Is
>>> there a way that I can obtain the x,y,z position of a sound emitter
>>> relative to the user's position?
>>
>> Perhaps I'm not clear, since I have a typo in the first sentence, and
>> that's why there were no answers.
>> Or, maybe it's a question that has been answered many times and I just
>> can't find it in the archives.
>>  Let me try again.
>>
>> How can I find the location (in x,y,z) of an object relative to the
>> user's position?
>
> I think your question hasn't been answered since OpenAL does this
> transformation for you. All you do is provide the transforms for the
> listener and the sound sources.
>
> You can of course, compute the relative position yourself; it's merely
> transforming the position of the sound source into the local frame of the
> listener which can be achieved simply by:
>
>  listener globalToLocal: speaker globalPosition.
>
> or (somewhat more efficiently) via:
>
>  listener globalTransform orthoNormInverse transformPoint: speaker
> globalPosition.