Audio setup with WAV file loading

src/rasdaq/Application.cs

@@ -1,6 +1,8 @@
 using OpenTK.Graphics.OpenGL4;
 using OpenTK.Windowing.Common;
 using OpenTK.Windowing.Desktop;
+
+using rasdaq.Audio;
 using rasdaq.Core.ECS;
 using rasdaq.Graphics;
 using rasdaq.Inputs;
@@ -22,6 +24,8 @@ public sealed class Application : IDisposable
     public static Application? Instance { get; private set; }
     internal InputManager InputManager { get; set; }
 
+    public AudioManager AudioManager { get; private set; }
+
     private List<World> _worlds = new();
     private GameWindow _gameWindow;
 
@@ -57,6 +61,7 @@ public Application(int width, int height, string title)
         _gameWindow.FramebufferResize += OnFramebufferResize;
 
         InputManager = new InputManager(new GameWindowWrapper(_gameWindow));
+        AudioManager = new AudioManager();
     }
 
     internal void RegisterWorld(World world)

src/rasdaq/Audio/Audio.cs

@@ -0,0 +1,29 @@
+using OpenTK.Audio.OpenAL;
+
+using rasdaq.Logging;
+
+namespace rasdaq.Audio;
+
+public class Audio : IDisposable
+{
+    public int Handle;
+
+    public Audio()
+    {
+        Handle = AL.GenBuffer();
+        // Check for errors
+        ALError error = AL.GetError();
+        if (error != ALError.NoError)
+        {
+            string err = $"OpenAL error while trying to create audio buffer: {error}";
+
+            Log.Error(err);
+            throw new Exception(err);
+        }
+    }
+
+    public void Dispose()
+    {
+        AL.DeleteBuffer(Handle);
+    }
+}

src/rasdaq/Audio/AudioManager.cs

@@ -0,0 +1,159 @@
+using OpenTK.Audio.OpenAL;
+
+using rasdaq.Logging;
+
+namespace rasdaq.Audio;
+
+public class AudioManager
+{
+    private static void CheckALCError(ALDevice device)
+    {
+        AlcError error = ALC.GetError(device);
+        if (error != AlcError.NoError)
+        {
+            string err = $"OpenAL error: {error}";
+            Log.Error(err);
+            throw new Exception(err);
+        }
+    }
+
+    private static void CheckALError()
+    {
+        ALError error = AL.GetError();
+        if (error != ALError.NoError)
+        {
+            string err = $"OpenAL error: {error}";
+            Log.Error(err);
+            throw new Exception(err);
+        }
+    }
+
+    /// <summary>
+    /// Initialize Audio for the Application, using the default audio device.
+    /// </summary>
+    /// <exception cref="Exception"></exception>
+    public AudioManager()
+    {
+        // Open the default audio device.
+        ALDevice device = ALC.OpenDevice(null);
+        if (device == ALDevice.Null)
+        {
+            string err = "Failed to open the default audio device.";
+            Log.Error(err);
+            throw new Exception(err);
+        }
+
+        // Create a context for the device.
+        ALContext context = ALC.CreateContext(device, new ALContextAttributes(null, null, null, null, null));
+        if (context == ALContext.Null)
+        {
+            ALC.CloseDevice(device);
+            string err = "Failed to create an OpenAL context.";
+            Log.Error(err);
+            throw new Exception(err);
+        }
+
+        // Check if we have any errors.
+        AlcError error = ALC.GetError(device);
+        CheckALCError(device);
+        // If no errors, make the context current.
+        ALC.MakeContextCurrent(context);
+    }
+
+    /// <summary>
+    /// Load a WAV file that contains PCM data only.
+    /// </summary>
+    /// <param name="path">Path to WAV file</param>
+    /// <returns>A integer handle referring to the loaded audio</returns>
+    /// <exception cref="Exception"></exception>
+    public Audio LoadAudio(string path)
+    {
+        // Create an OpenAL buffer for the data to go in.
+        Audio audio = new Audio();
+
+        // Load the WAV file
+        WAVLoader.WAVData wavData = WAVLoader.LoadWav(path);
+
+        // Discern the format of the audio data based on number of channels and bits per sample.
+        ALFormat format;
+        if (wavData.Format.NumChannels == 1)
+        {
+            if (wavData.Format.BitsPerSample == 8)
+            {
+                format = ALFormat.Mono8;
+            }
+            else if (wavData.Format.BitsPerSample == 16)
+            {
+                format = ALFormat.Mono16;
+            }
+            else
+            {
+                string err = $"Unsupported bits per sample: {wavData.Format.BitsPerSample}";
+                Log.Error(err);
+                throw new Exception(err);
+            }
+        }
+        else if (wavData.Format.NumChannels == 2)
+        {
+            if (wavData.Format.BitsPerSample == 8)
+            {
+                format = ALFormat.Stereo8;
+            }
+            else if (wavData.Format.BitsPerSample == 16)
+            {
+                format = ALFormat.Stereo16;
+            }
+            else
+            {
+                string err = $"Unsupported bits per sample: {wavData.Format.BitsPerSample}";
+                Log.Error(err);
+                throw new Exception(err);
+            }
+        }
+        else
+        {
+            string err = $"Unsupported number of channels: {wavData.Format.NumChannels}";
+            Log.Error(err);
+            throw new Exception(err);
+        }
+
+        // Load the audio data into the OpenAL buffer.
+        AL.BufferData(audio.Handle, format, wavData.Data.Data, (int)wavData.Format.SampleRate);
+
+        // Check if we have any errors from trying to load the audio data.
+        CheckALError();
+
+        return audio;
+    }
+
+    /// <summary>
+    /// Add a loaded audio file to an audio source, so that it can be played.
+    /// </summary>
+    /// <param name="audio">Audio file</param>
+    /// <param name="audioSource">Audio source</param>
+    public void AttachAudioToSource(Audio audio, AudioSource audioSource)
+    {
+        AL.Source(audioSource.Handle, ALSourcei.Buffer, audio.Handle);
+        CheckALError();
+    }
+
+    /// <summary>
+    /// Play back an audio source that has audio attached to it.
+    /// </summary>
+    /// <param name="source"></param>
+    public void PlaySource(AudioSource audioSource)
+    {
+        AL.SourcePlay(audioSource.Handle);
+        CheckALError();
+    }
+
+    /// <summary>
+    /// Stop playback of an audio source.
+    /// </summary>
+    /// <param name="source"></param>
+    public void StopSource(AudioSource audioSource)
+    {
+        AL.SourceStop(audioSource.Handle);
+        CheckALError();
+    }
+}

src/rasdaq/Audio/AudioSource.cs

@@ -0,0 +1,29 @@
+using OpenTK.Audio.OpenAL;
+
+using rasdaq.Logging;
+
+namespace rasdaq.Audio;
+
+public class AudioSource : IDisposable
+{
+    public int Handle;
+
+    public AudioSource()
+    {
+        Handle = AL.GenSource();
+        // Check for errors
+        ALError error = AL.GetError();
+        if (error != ALError.NoError)
+        {
+            string err = $"OpenAL error while trying to create audio source: {error}";
+
+            Log.Error(err);
+            throw new Exception("OpenAL error while trying to create audio source: " + error);
+        }
+    }
+
+    public void Dispose()
+    {
+        AL.DeleteSource(Handle);
+    }
+}