[Kde-games-devel] Unavailable, Tagaro progress, sound APIs (again)

[Stefan Majewsky]

Am Donnerstag, 9. September 2010, 23:34:16 schrieb Parker Coates:
> I think a simple, Qt-style OpenAL library is probably the thing we
> need most technology-wise in KDEGames right now. While most of the
> goals of Tagaro seem to improve on solutions we already have, I think
> the lack of a good sound system is a major hole in our current
> offerings.

I did not check Phonon in detail yet, but I got OpenAL + libsndfile (which can 
read WAV and Ogg/Vorbis) working in a test application. The libsndfile 
dependency can be eliminated later, I first want something that works (esp. 
because hacking with sound libs is quite difficult for unexperienced me: every 
possible fault just results in no sound being played).

> Have you actually done an in depth review of GluonAudio? Is it really
> so bad that starting from scratch is preferable to a fork?

The GluonAudio API does not really abstract OpenAL, it's basically a C++ 
wrapper for OpenAL. As such, it uses OpenAL datatypes and, and it by and large 
represents the OpenAL domain model.

However, no game developer will want to deal with selecting devices and 
creating sound contexts. They want the default device, and be done.

After writing my test application, I wrote up an API sketch (see attachment), 
which consists of two classes: an AudioScene singleton which has global 
properties (it has to be a singleton because there is only one default sound 
output), and a Sound class which loads and plays sound files. Loading and 
playing a sound is just Tagaro::Sound(file).play()

I chose not to implement too much functionality. Games are not like sound 
editing programs, they do not need most of the advanced API in OpenAL. The 
only "exotic" OpenAL functionality I'm exposing is positional playback, which 
I am very much interested in.

Of course, this API sketch is not finished (e.g. it misses a looping property 
for background music). But instead of extending the API to exotic usecases 
which need access to OpenAL internals (like buffers and sources), I would much 
rather work on Qt integration from this point, like coupling positional 
playback coordinates with QGV scene coordinates. OpenAL is by now completely 
abstracted, and can be replaced by any other sound framework with low latency 
and positional playback.

Greetings
Stefan
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