Merge pull request #84648 from NiftyHat/patch-1

Add C# example for the AudioStreamGenerator code snippet
This commit is contained in:
Rémi Verschelde 2023-11-10 10:45:20 +01:00
commit 804c1926c9
No known key found for this signature in database
GPG key ID: C3336907360768E1

View file

@ -6,7 +6,8 @@
<description>
[AudioStreamGenerator] is a type of audio stream that does not play back sounds on its own; instead, it expects a script to generate audio data for it. See also [AudioStreamGeneratorPlayback].
Here's a sample on how to use it to generate a sine wave:
[codeblock]
[codeblocks]
[gdscript]
var playback # Will hold the AudioStreamGeneratorPlayback.
@onready var sample_hz = $AudioStreamPlayer.stream.mix_rate
var pulse_hz = 440.0 # The frequency of the sound wave.
@ -24,7 +25,39 @@
for i in range(frames_available):
playback.push_frame(Vector2.ONE * sin(phase * TAU))
phase = fmod(phase + increment, 1.0)
[/codeblock]
[/gdscript]
[csharp]
[Export] public AudioStreamPlayer Player { get; set; }
private AudioStreamGeneratorPlayback _playback; // Will hold the AudioStreamGeneratorPlayback.
private float _sampleHz;
private float _pulseHz = 440.0f; // The frequency of the sound wave.
public override void _Ready()
{
if (Player.Stream is AudioStreamGenerator generator) // Type as a generator to access MixRate.
{
_sampleHz = generator.MixRate;
Player.Play();
_playback = (AudioStreamGeneratorPlayback)Player.GetStreamPlayback();
FillBuffer();
}
}
public void FillBuffer()
{
double phase = 0.0;
float increment = _pulseHz / _sampleHz;
int framesAvailable = _playback.GetFramesAvailable();
for (int i = 0; i &lt; framesAvailable; i++)
{
_playback.PushFrame(Vector2.One * (float)Mathf.Sin(phase * Mathf.Tau));
phase = Mathf.PosMod(phase + increment, 1.0);
}
}
[/csharp]
[/codeblocks]
In the example above, the "AudioStreamPlayer" node must use an [AudioStreamGenerator] as its stream. The [code]fill_buffer[/code] function provides audio data for approximating a sine wave.
See also [AudioEffectSpectrumAnalyzer] for performing real-time audio spectrum analysis.
[b]Note:[/b] Due to performance constraints, this class is best used from C# or from a compiled language via GDExtension. If you still want to use this class from GDScript, consider using a lower [member mix_rate] such as 11,025 Hz or 22,050 Hz.