9. Positional Sound
And now for something completely different ....”
We’re not kidding. The OpenAL library, which is included with both Mac OS X and iOS, is a completely different audio framework than Core Audio’s pull-based world of audio units. It’s different in part because it comes from a third party. It also solves completely different problems—namely, placing audio in a 3D sound field. Its primary purpose is to deliver audio for games, but you can use it as a general-purpose audio engine because of its interesting traits that you can bring to your own applications.
In this chapter, you dive into the design and architecture of OpenAL and look at how it represents positional sound as a C API. After you’re introduced to its core concepts, ...