add sdl to cmake via package find

CMakeLists.txt

@@ -27,6 +27,7 @@ pkg_check_modules(LIBAV REQUIRED IMPORTED_TARGET
     libavutil
 )
 PKG_SEARCH_MODULE(SDL2 REQUIRED sdl2)
+find_package(SDL2 REQUIRED CONFIG)
 
 file(GLOB_RECURSE PROJECT_SOURCES src/*.cpp)
 file(GLOB_RECURSE PROJECT_HEADERS src/*.h)
@@ -47,6 +48,7 @@ target_link_libraries(CryliaPlayer PRIVATE
     ${SDL_IMAGE_LIBRARY}
     ${SDL_MIXER_LIBRARY}
     PkgConfig::LIBAV
+    ${SDL2}
 )
 
 install(TARGETS CryliaPlayer

src/core/audio/audio.cpp

@@ -31,6 +31,9 @@ void Audio::StopMusic( ) {
 }
 
 void Audio::PlaySong(const std::string path) {
+  if (music)
+    Mix_FreeMusic(music);
+
   this->path = path;
 
   music = Mix_LoadMUS(path.c_str( ));
@@ -55,7 +58,7 @@ void Audio::ResumeMusic( ) {
 }
 
 bool Audio::IsMusicPlaying( ) {
-  return Mix_PlayingMusic( );
+  return (Mix_PlayingMusic( ) != 0);
 }
 
 std::string Audio::GetTitle( ) {