Added methods to modify audio pitch (#2381)

* Added methods to modify audio  pitch

* Replaced if statments with clamp

Author: Janglee123

core/audio/AudioEngine.cpp

@@ -216,6 +216,21 @@ void AudioEngine::setVolume(AUDIO_ID audioID, float volume)
     }
 }
 
+void AudioEngine::setPitch(AUDIO_ID audioID, float pitch)
+{
+    auto it = _audioIDInfoMap.find(audioID);
+    if (it != _audioIDInfoMap.end())
+    {
+        pitch = std::clamp(pitch, 0.5f, 2.0f);
+
+        if (it->second.pitch != pitch)
+        {
+            _audioEngineImpl->setPitch(audioID, pitch);
+            it->second.pitch = pitch;
+        }
+    }
+}
+
 void AudioEngine::pause(AUDIO_ID audioID)
 {
     auto it = _audioIDInfoMap.find(audioID);

core/audio/AudioEngine.h

@@ -189,6 +189,22 @@ class AX_DLL AudioEngine
      */
     static float getVolume(AUDIO_ID audioID);
 
+    /**
+     * Sets pitch for an audio instance.
+     *
+     * @param audioID An audioID returned by the play2d function.
+     * @param pitch Volume value (range from 0.5 to 2.0).
+     */
+    static void setPitch(AUDIO_ID audioID, float pitch);
+
+    /**
+     * Gets the volume value of an audio instance.
+     *
+     * @param audioID An audioID returned by the play2d function.
+     * @return pitch value (range from 0.5 to 2.0).
+     */
+    static float getPitch(AUDIO_ID audioID);
+
     /**
      * Pause an audio instance.
      *
@@ -354,6 +370,7 @@ class AX_DLL AudioEngine
         ProfileHelper* profileHelper;
 
         float volume;
+        float pitch;
         bool loop;
         float duration;
         AudioState state;

core/audio/AudioEngineImpl.cpp

@@ -551,6 +551,7 @@ AUDIO_ID AudioEngineImpl::play2d(std::string_view filePath, bool loop, float vol
     player->_alSource = alSource;
     player->_loop     = loop;
     player->_volume   = volume;
+    player->_pitch    = 1.0f;
     if (time > 0.0f)
     {
         player->_currTime  = time;
@@ -644,6 +645,30 @@ void AudioEngineImpl::setVolume(AUDIO_ID audioID, float volume)
     }
 }
 
+void AudioEngineImpl::setPitch(AUDIO_ID audioID, float pitch)
+{
+    std::unique_lock<std::recursive_mutex> lck(_threadMutex);
+    auto iter = _audioPlayers.find(audioID);
+    if (iter == _audioPlayers.end())
+        return;
+
+    auto player = iter->second;
+    lck.unlock();
+
+    player->_pitch = pitch;
+
+    if (player->_ready)
+    {
+        alSourcef(player->_alSource, AL_PITCH, pitch);
+
+        auto error = alGetError();
+        if (error != AL_NO_ERROR)
+        {
+            AXLOGE("{}: audio id = {}, error = {:#x}", __FUNCTION__, audioID, error);
+        }
+    }
+}
+
 void AudioEngineImpl::setLoop(AUDIO_ID audioID, bool loop)
 {
     std::unique_lock<std::recursive_mutex> lck(_threadMutex);

core/audio/AudioEngineImpl.h

@@ -51,6 +51,7 @@ class AX_DLL AudioEngineImpl : public ax::Object
     bool init();
     AUDIO_ID play2d(std::string_view fileFullPath, bool loop, float volume, float time);
     void setVolume(AUDIO_ID audioID, float volume);
+    void setPitch(AUDIO_ID audioID, float pitch);
     void setLoop(AUDIO_ID audioID, bool loop);
     bool pause(AUDIO_ID audioID);
     bool resume(AUDIO_ID audioID);

core/audio/AudioPlayer.h

@@ -71,6 +71,7 @@ class AX_DLL AudioPlayer
     AudioCache* _audioCache;
 
     float _volume;
+    float _pitch;
     bool _loop;
     std::function<void(AUDIO_ID, std::string_view)> _finishCallbak;