This is a preview! This is not the official Castle Game Engine website (official website is here). This is only a preview for developers, to see the next website before the release, and to see the documentation for the unstable engine version (from GitHub master).
OpenAL (3D Sound)
is a cool cross-platform library for 3D sound.
All the sound played by our engine goes through it.
For developers, the decription how to use 3D sound in Castle Game Engine
is in manual about sound.
2. Installing OpenAL
Generally, you can install OpenAL from many sources, you can even
get optimized OpenAL drivers from your sound card manufacturer.
Section below describes how to install OpenAL in the
simplest and most often case.
Install appropriate package for your Linux distribution.
Look for a package named like libopenal*.
My games work with both common OpenAL implementations:
OpenAL Sample Implementation (the original implementation,
from Loki, unmaintained) and
(the newer, maintained version). Modern distributions (at least Debian
and Ubuntu) contain OpenAL Soft.
Simple pkg_add -r openal command should do
OpenAL libraries (DLL files) should already be included in all
binary packages of my games under Windows. So you don't have to do anything.
However, you're free to remove appropriate DLL files
(OpenAL32.dll and wrap_oal.dll) provided in my archives
OpenAL yourself. This is especially handy if you
want to use other OpenAL implementation than the one from Creative.
OpenAL libraries that are provided by default come from
free OpenAL installer (choose oalinst,
that is OpenAL Installer for Windows).
3. Command-line options respected by all my programs that use OpenAL
Don't output any sound, even if OpenAL is available and seems perfectly working.
Our programs will not even try to initialize OpenAL in this case.
Note that you don't have to use this option if you don't have
OpenAL installed. This parameter is useful only if you
have OpenAL, but you don't want to use it for
whatever reason (e.g. because your cat sleeps on the
chair beside you and you don't want to wake him up).
Use given DEVICE-NAME for sound output. Usually, the default
one should be the best.
To list the available devices use the --help command-line option
(at the --audio-device description you will see a list of devices detected).
In The Castle you can also see and choose them by the Sound output device menu.
In view3dscene you have comfortable menu File -> Preferences -> Sound Device.
You may see two devices with newer OpenAL implementation:
"Generic Hardware" (uses DirectSound3D)
and "Generic Software" (uses DirectSound).
As far as I know, "Generic Software" can only support
stereo sound (2 channels, not more). On the other hand, it sometimes
sounds better than "Generic Hardware".
So be sure to try both devices and choose the better one.
Linux and FreeBSD users with OpenAL-Soft (newer) implementation:
The default device selected on Linux should usually be ALSA,
and should work perfectly on modern systems.
A useful device is "Wave File Writer", to record
3D sound to file. Note that you have to specify output filename
in config file, otherwise it will not work. For example,
make a file $HOME/.alsoftrc with two lines:
file = /tmp/output.wav
For more configuration options, look into /etc/openal/alsoft.conf
that should be installed with openal-soft package. It contains
many comments about the possible options.
Linux and FreeBSD users with OpenAL Sample (older) implementation:
The following devices are available:
operating system native
The default device.
Simple DirectMedia Layer backend
Note that it seems terribly unstable. Use at your own risk.
Esound daemon backend
While it works OK,
it tries to acquire the exclusive ownership
over sound device. So, unlike most other programs that use ALSA,
OpenAL programs by default cannot play sound when some
other program already plays sound. For example,
you cannot run rhyrthmbox and listen to your own chosen
music while playing my games.
The workaround is to run my games through
WAVE file output
A file named like openal-0.wav will be generated
that contains recorded sound.
Note that OpenAL
generates somewhat buggy WAV file, and e.g. gstreamer-based
programs may not want to play it. My programs will play it,
but only because I made a workaround specifically for this.
I found that it's usually a good workaround
to convert the WAV file with sox,
like sox openal-0.wav newopenal-0.wav.
Such WAV file generated by sox should be readable everywhere.
I reported this problem to Debian OpenAL package
(probably a problem is general and fix will be generally usable
In the simplest case, to use some other device, e.g. alsa,
just run program with command-line option like:
--audio-device "'(( devices '(alsa) ))"
(Yes, the first argument's character is an apostrophe,
and the whole argument is quoted to avoid being
splitted by shell. No, it's not Lisp, but it was
designed to look similar.)
Then if you will find that e.g. alsa device
sounds best and you want my programs (and all
other programs that use OpenAL) to always use
alsa device, you can create file
/etc/openalrc or $HOME/.openalrc with