Fixed build with disabled ADLMIDI, OPNMIDI, and Timidity

CMakeLists.txt

@@ -473,15 +473,15 @@ if(USE_MIDI)
             endif()
             set(LIBMATH_NEEDED 1)
             list(APPEND SDLMixerX_LINK_LIBS ${LIBADLMIDI_LIB})
-            list(APPEND SDLMixerX_SOURCES
-                ${SDLMixerX_SOURCE_DIR}/src/codecs/music_midi_adl.c)
         endif()
     endif()
+    # Keep in build list even not used (to link necessary calls)
+    list(APPEND SDLMixerX_SOURCES ${SDLMixerX_SOURCE_DIR}/src/codecs/music_midi_adl.c)
 
     option(USE_MIDI_OPNMIDI    "Build with libOPNMIDI OPN2 Emulator based MIDI sequencer support" ON)
     if(USE_MIDI_OPNMIDI)
         if(USE_SYSTEM_AUDIO_LIBRARIES)
-            check_library_exists(OPNMIDI opn_init "opnmidi.h" FOUND_OPNMIDI)
+            check_library_exists(OPNMIDI opn2_init "opnmidi.h" FOUND_OPNMIDI)
             find_path(LIBOPNMIDI_INCLUDE_DIR "opnmidi.h")
             find_library(LIBOPNMIDI_LIB NAMES OPNMIDI)
             message("OPNMIDI: ${LIBOPNMIDI_INCLUDE_DIR} ${LIBOPNMIDI_LIB}")
@@ -502,10 +502,10 @@ if(USE_MIDI)
             endif()
             set(LIBMATH_NEEDED 1)
             list(APPEND SDLMixerX_LINK_LIBS ${LIBOPNMIDI_LIB})
-            list(APPEND SDLMixerX_SOURCES
-                ${SDLMixerX_SOURCE_DIR}/src/codecs/music_midi_opn.c)
         endif()
     endif()
+    # Keep in build list even not used (to link necessary calls)
+    list(APPEND SDLMixerX_SOURCES ${SDLMixerX_SOURCE_DIR}/src/codecs/music_midi_opn.c)
 
     option(USE_MIDI_TIMIDITY   "Build with Timidity wave table MIDI sequencer support" ON)
     if(USE_MIDI_TIMIDITY AND NOT USE_SYSTEM_AUDIO_LIBRARIES)
@@ -521,9 +521,9 @@ if(USE_MIDI)
                          HINTS "${AUDIO_CODECS_INSTALL_PATH}/lib")
         endif()
         list(APPEND SDLMixerX_LINK_LIBS ${LIBTIMIDITY_LIB})
-        list(APPEND SDLMixerX_SOURCES
-            ${SDLMixerX_SOURCE_DIR}/src/codecs/music_timidity.c)
     endif()
+    # Keep in build list even not used (to link necessary calls)
+    list(APPEND SDLMixerX_SOURCES ${SDLMixerX_SOURCE_DIR}/src/codecs/music_timidity.c)
 
     option(USE_MIDI_FLUIDSYNTH "Build with FluidSynth wave table MIDI sequencer support" OFF)
     if(USE_MIDI_FLUIDSYNTH)
@@ -788,3 +788,17 @@ install(FILES
         include/SDL_mixer_ext/SDL_mixer_ext.h
         DESTINATION include/SDL2)
 
+if(USE_SYSTEM_AUDIO_LIBRARIES)
+    message("==== SDL Mixer X system-wide libraries ====")
+    message("  Vorbis found: ${FOUND_VORBIS}")
+    message("  OPUS found: ${FOUND_OPUS}")
+    message("  FLAC found: ${FOUND_FLAC}")
+    message("  libMAD found: ${FOUND_MAD}")
+    message("  MPG123 found: ${MPG123_FOUND}")
+    message("  ModPlug found: ${FOUND_MODPLUG}")
+    message("  MikMod found: ${FOUND_MIKMOD}")
+    message("  GME found: ${FOUND_GME}")
+    message("  libADLMIDI found: ${FOUND_ADLMIDI}")
+    message("  libOPNMIDI found: ${FOUND_OPNMIDI}")
+    message("  FluidSynth found: ${FOUND_FLUIDSYNTH}")
+endif()