Added SDL2 Mixer example over Mix_HookMusic()

2 files changed, 220 insertions, 0 deletions

diff --git a/examples/sdl2_mixer/CMakeLists.txt b/examples/sdl2_mixer/CMakeLists.txt
new file mode 100644
index 0000000..caaa4ca
--- /dev/null
+++ b/examples/sdl2_mixer/CMakeLists.txt
@@ -0,0 +1,48 @@
+if(POLICY CMP0111)
+    cmake_policy(SET CMP0111 NEW)
+endif()
+
+find_package(SDL2 REQUIRED)
+find_package(SDL2_MIXER REQUIRED)
+
+add_library(ADLMIDIEXAMPLE_SDL2 INTERFACE)
+
+if(TARGET SDL2_mixer::SDL2_mixer)
+    target_include_directories(ADLMIDIEXAMPLE_SDL2 INTERFACE ${SDL2_MIXER_INCLUDE_DIRS})
+else()
+    string(STRIP ${SDL2_MIXER_LIBRARIES} SDL2_MIXER_LIBRARIES)
+    target_include_directories(ADLMIDIEXAMPLE_SDL2 INTERFACE ${SDL2_MIXER_INCLUDE_DIRS})
+    target_link_libraries(ADLMIDIEXAMPLE_SDL2 INTERFACE ${SDL2_MIXER_LIBRARIES})
+endif()
+
+if(TARGET SDL2::SDL2)
+    if(MINGW)
+        target_link_libraries(ADLMIDIEXAMPLE_SDL2 INTERFACE mingw32 SDL2::SDL2main SDL2::SDL2)
+    else()
+        target_link_libraries(ADLMIDIEXAMPLE_SDL2 INTERFACE SDL2::SDL2)
+    endif()
+    target_include_directories(ADLMIDIEXAMPLE_SDL2 INTERFACE ${SDL2_INCLUDE_DIRS})
+else()
+    string(STRIP ${SDL2_LIBRARIES} SDL2_LIBRARIES)
+    target_include_directories(ADLMIDIEXAMPLE_SDL2 INTERFACE ${SDL2_INCLUDE_DIRS})
+    target_link_libraries(ADLMIDIEXAMPLE_SDL2 INTERFACE ${SDL2_LIBRARIES})
+endif()
+
+add_executable(adlmidi_sdl2_mixer_demo sdl2_mixer_example.c)
+target_link_libraries(adlmidi_sdl2_mixer_demo PRIVATE ADLMIDI ADLMIDIEXAMPLE_SDL2)
+
+set_nopie(adlmidi_sdl2_mixer_demo)
+
+if(NOT MSVC)
+    target_link_libraries(adlmidi_sdl2_mixer_demo PRIVATE pthread)
+endif()
+if(NOT WIN32)
+    target_link_libraries(adlmidi_sdl2_mixer_demo PRIVATE dl m)
+endif()
+
+if(TARGET ADLMIDI_shared)
+    set_target_properties(adlmidi_sdl2_mixer_demo PROPERTIES INSTALL_RPATH "$ORIGIN/../lib")
+endif()
+
+install(TARGETS adlmidi_sdl2_mixer_demo
+        RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")
diff --git a/examples/sdl2_mixer/sdl2_mixer_example.c b/examples/sdl2_mixer/sdl2_mixer_example.c
new file mode 100644
index 0000000..4a57307
--- /dev/null
+++ b/examples/sdl2_mixer/sdl2_mixer_example.c
@@ -0,0 +1,172 @@
+#include <stdio.h>
+#include <signal.h>
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_mixer.h>
+
+#include <adlmidi.h>
+
+/* prototype for our audio callback */
+/* see the implementation for more information */
+void my_audio_callback(void *midi_player, Uint8 *stream, int len);
+
+/* variable declarations */
+static Uint32 is_playing = 0; /* remaining length of the sample we have to play */
+
+static struct ADLMIDI_AudioFormat s_audioFormat;
+
+static void stop_playing(int sig)
+{
+    (void)sig;
+    is_playing = 0;
+}
+
+int main(int argc, char *argv[])
+{
+    /* local variables */
+    static Uint16                   obtained_format; /* Format of the audio device */
+    static struct ADL_MIDIPlayer    *midi_player = NULL; /* Instance of ADLMIDI player */
+    static const char               *music_path = NULL; /* Path to music file */
+
+    signal(SIGINT, stop_playing);
+    signal(SIGTERM, stop_playing);
+
+    if (argc < 2)
+    {
+        fprintf(stderr, "\n"
+                        "\n"
+                        "No given files to play!\n"
+                        "\n"
+                        "Syntax: %s <path-to-MIDI-file>\n"
+                        "\n", argv[0]);
+        return 2;
+    }
+
+    music_path = argv[1];
+
+    /* Initialize SDL.*/
+    if(SDL_Init(SDL_INIT_AUDIO) < 0)
+        return 1;
+
+    /* Initialize ADLMIDI */
+    midi_player = adl_init(44100);
+    if (!midi_player)
+    {
+        fprintf(stderr, "Couldn't initialize ADLMIDI: %s\n", adl_errorString());
+        return 1;
+    }
+
+    adl_switchEmulator(midi_player, ADLMIDI_EMU_NUKED);
+
+    /* Open the audio device */
+    if (Mix_OpenAudio(44100, AUDIO_S16SYS, 2, 2048) < 0)
+    {
+        fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
+        return 1;
+    }
+
+    /* set the callback function */
+    /* set ADLMIDI's descriptor as userdata to use it for sound generation */
+    Mix_HookMusic(my_audio_callback, midi_player);
+
+    Mix_QuerySpec(NULL, &obtained_format, NULL);
+
+    switch(obtained_format)
+    {
+    case AUDIO_S8:
+        s_audioFormat.type = ADLMIDI_SampleType_S8;
+        s_audioFormat.containerSize = sizeof(int8_t);
+        s_audioFormat.sampleOffset = sizeof(int8_t) * 2;
+        break;
+    case AUDIO_U8:
+        s_audioFormat.type = ADLMIDI_SampleType_U8;
+        s_audioFormat.containerSize = sizeof(uint8_t);
+        s_audioFormat.sampleOffset = sizeof(uint8_t) * 2;
+        break;
+    case AUDIO_S16:
+        s_audioFormat.type = ADLMIDI_SampleType_S16;
+        s_audioFormat.containerSize = sizeof(int16_t);
+        s_audioFormat.sampleOffset = sizeof(int16_t) * 2;
+        break;
+    case AUDIO_U16:
+        s_audioFormat.type = ADLMIDI_SampleType_U16;
+        s_audioFormat.containerSize = sizeof(uint16_t);
+        s_audioFormat.sampleOffset = sizeof(uint16_t) * 2;
+        break;
+    case AUDIO_S32:
+        s_audioFormat.type = ADLMIDI_SampleType_S32;
+        s_audioFormat.containerSize = sizeof(int32_t);
+        s_audioFormat.sampleOffset = sizeof(int32_t) * 2;
+        break;
+    case AUDIO_F32:
+        s_audioFormat.type = ADLMIDI_SampleType_F32;
+        s_audioFormat.containerSize = sizeof(float);
+        s_audioFormat.sampleOffset = sizeof(float) * 2;
+        break;
+    }
+
+    /* Optionally Setup ADLMIDI as you want */
+
+    adl_setNumChips(midi_player, 1);
+
+    /* Set using of embedded bank by ID */
+    /*adl_setBank(midi_player, 68);*/
+
+    /* Set using of custom bank (WOPL format) loaded from a file */
+    /*adl_openBankFile(midi_player, "/home/vitaly/Yandex.Disk/Музыка/Wolfinstein.wopl");*/
+
+    /* Open the MIDI (or MUS, IMF or CMF) file to play */
+    if (adl_openFile(midi_player, music_path) < 0)
+    {
+        fprintf(stderr, "Couldn't open music file: %s\n", adl_errorInfo(midi_player));
+        SDL_CloseAudio();
+        adl_close(midi_player);
+        return 1;
+    }
+
+    is_playing = 1;
+    /* Start playing */
+    SDL_PauseAudio(0);
+
+    printf("Playing... Hit Ctrl+C to quit!\n");
+
+    /* wait until we're don't playing */
+    while (is_playing)
+    {
+         SDL_Delay(100);
+    }
+
+    /* shut everything down */
+    SDL_CloseAudio();
+    adl_close(midi_player);
+
+    return 0;
+}
+
+/*
+ audio callback function
+ here you have to copy the data of your audio buffer into the
+ requesting audio buffer (stream)
+ you should only copy as much as the requested length (len)
+*/
+void my_audio_callback(void *midi_player, Uint8 *stream, int len)
+{
+    if (!is_playing)
+      return;
+
+    struct ADL_MIDIPlayer* p = (struct ADL_MIDIPlayer*)midi_player;
+
+    /* Convert bytes length into total count of samples in all channels */
+    int samples_count = len / s_audioFormat.containerSize;
+
+    /* Take some samples from the ADLMIDI */
+    samples_count = adl_playFormat(p, samples_count,
+                                   stream,
+                                   stream + s_audioFormat.containerSize,
+                                   &s_audioFormat);
+
+    if(samples_count <= 0)
+    {
+        is_playing = 0;
+        SDL_memset(stream, 0, len);
+    }
+}