fix #506: Initialize audio when used for the first time

Author: adazem009

src/audio/audioengine.cpp

@@ -10,15 +10,31 @@ AudioEngine AudioEngine::instance;
 
 ma_engine *AudioEngine::engine()
 {
-    return &instance.m_engine;
+    if (!instance.m_initialized)
+        instance.init();
+
+    return instance.m_initialized ? &instance.m_engine : nullptr;
 }
 
 bool AudioEngine::initialized()
 {
+    if (!instance.m_initialized)
+        instance.init();
+
     return instance.m_initialized;
 }
 
 AudioEngine::AudioEngine()
+{
+}
+
+AudioEngine::~AudioEngine()
+{
+    if (m_initialized)
+        ma_engine_uninit(&m_engine);
+}
+
+void AudioEngine::init()
 {
     ma_result result;
     result = ma_engine_init(NULL, &m_engine);
@@ -30,9 +46,3 @@ AudioEngine::AudioEngine()
 
     m_initialized = true;
 }
-
-AudioEngine::~AudioEngine()
-{
-    if (m_initialized)
-        ma_engine_uninit(&m_engine);
-}

src/audio/audioengine.h

@@ -19,6 +19,8 @@ class AudioEngine
         AudioEngine();
         ~AudioEngine();
 
+        void init();
+
         static AudioEngine instance;
         ma_engine m_engine;
         bool m_initialized = false;