initial commit

src/audio/audio_manager.h

@@ -0,0 +1,93 @@
+#pragma once
+
+#include "config/config_manager.h"
+#include <SDL3_mixer/SDL_mixer.h>
+#include <mutex>
+#include <string>
+#include <vector>
+
+namespace radiantwave::audio {
+
+struct AudioDeviceItem {
+    std::string raw_name;      // e.g. alsa_output.pci-0000_00_1f.3.analog-stereo
+    std::string friendly_name; // e.g. "Built-In Speakers"
+};
+
+// Maps raw technical audio device strings to user-friendly labels
+std::string mapToFriendlyDeviceName(const std::string& raw_name);
+
+class AudioManager {
+public:
+    AudioManager();
+    ~AudioManager();
+
+    // Non-copyable
+    AudioManager(const AudioManager&) = delete;
+    AudioManager& operator=(const AudioManager&) = delete;
+
+    // Initialize SDL3_mixer audio system
+    bool initialize(config::ConfigManager& config);
+
+    // Shutdown audio subsystem
+    void shutdown();
+
+    // Enumerate playback devices with friendly names
+    std::vector<AudioDeviceItem> getPlaybackDevices() const;
+
+    // Master volume control (0 - 100)
+    void setVolume(int volume_0_to_100);
+    int getVolume() const;
+
+    // Master audio enable / mute toggle
+    void setAudioEnabled(bool enabled);
+    bool isAudioEnabled() const;
+
+    // Audio device selection
+    bool switchDevice(const std::string& raw_device_name);
+    std::string getCurrentDevice() const;
+
+    // Playback control
+    bool playTrack(const std::string& wav_filename);
+    void stopTrack();
+
+    // Filename of the track currently loaded in the active slot ("" if none).
+    std::string currentTrack() const;
+
+    // Fade playback control (used by the scroller page)
+    bool playTrackFadeIn(const std::string& wav_filename, float seconds);
+    bool playTrackCrossfade(const std::string& wav_filename, float seconds);
+    // Fades any playing track out over `seconds`. Returns false when nothing
+    // was playing, so callers can skip teardown delays tied to the fade.
+    bool stopTrackFadeOut(float seconds);
+
+    // Drive in-progress fade ramps; call once per frame.
+    void update(float dt);
+
+private:
+    struct TrackSlot {
+        MIX_Track* track = nullptr;
+        MIX_Audio* audio = nullptr;
+        float fadeInDuration = 0.0f;   // >0 while ramping in (seconds)
+        float fadeInElapsed = 0.0f;
+        float fadeOutRemaining = 0.0f; // >0 while fading out (seconds)
+    };
+
+    float effectiveGain() const;
+    bool loadTrackInto(int slotIndex, const std::string& wav_filename);
+    void startFadeIn(int slotIndex, float seconds);
+
+    config::ConfigManager* configManager_ = nullptr;
+
+    bool initialized_ = false;
+    bool enabled_ = true;
+    int volume_ = 80; // 0 - 100
+    std::string currentDevice_ = "";
+    std::string currentTrack_ = "";
+
+    MIX_Mixer* mixer_ = nullptr;
+    TrackSlot slots_[2];
+    int activeSlot_ = 0;
+    mutable std::mutex mutex_;
+};
+
+} // namespace radiantwave::audio