Simulant has a full-featured audio system that makes it easy to load and play sound effects and streams.
Sounds
are an Asset
, like Textures
or Materials
, and so can be loaded using an asset manager, probably using
new_sound_from_file(path);
Supported sound formats are .wav and .ogg.
Sounds
are played through Sources
. All StageNodes
are a sound Source
, as is the Window
itself. You can play a sounds
by using the play_sound(id, repeat)
method on the Source
. In the case of the Window
the id
must be the ID of a sound
loaded by the shared_assets
manager, in the case of StageNodes
the sound must be either in the associated Stage
asset manager
or shared_assets
.
Playing a sound from a StageNode
will use positional audio to make it seem like the sound is coming from the location of the node. Sounds played
through the Window
will not have any positional effect - this makes the Window
perfect for playing a level soundtrack for example.
The repeat
argument of play_sound
can be one of the following:
AUDIO_REPEAT_NONE
- The sound will stop playing when it finishesAUDIO_REPEAT_FOREVER
- The sound will loop forever until manually stoppedThe volume of a playing sound can be controlled on a per-Source basis using Source::set_gain(gain)
where gain is clamped between 0 and 1. By default
all sounds are played at maximum gain.
Simulant applications have a global audio listener which is stored on the Window
. The audio listener represents the position and orientation of where sounds are heard.
By default, the audio listener is set to the Camera
used in the first active pipeline in the compositor. If there are no active pipelines, there is no listener.
You will likely need to manually set the audio listener, particularly if you have more than one pipeline. You can do this with the Window::set_audio_listener(node)
method. If the
audio listener node is destroyed, then audio listener behaviour will revert back to default.
Sometimes you will have a situation where you need to play a sound from the position of a StageNode
, but the node itself is due to be destroyed. For example,
an explosion sound effect might outlive the ParticleSystem
that represents the explosion - so how can you play the full sound?
There are a few options, here are a couple.
One option is to hide the node, but destroy it later:
node->set_visible(false);
node->play_sound(explosion);
node->destroy_after(Seconds(5));
Alternatively, you could specifically create a node to play the sound effect:
auto sound_node = node->stage->new_actor();
sound_node->move_to(node->absolute_position());
sound_node->play_sound(explosion);
sound_node->destroy_after(Seconds(5));