path: root/games/sdl3-doom/patches/0001-i_sdlmusic-port-music-backend-to-the-SDL3_mixer-3.2-.patch

From 0898b8bc17127829ea44325985e70c49c800ff21 Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Tue, 9 Jun 2026 16:25:51 +0100
Subject: [PATCH] i_sdlmusic: port music backend to the SDL3_mixer 3.2 MIX_*
 API

The Mix_* SDL_mixer API used by this port was removed in SDL_mixer 3.2.0.
Port the music backend to the new track-based MIX_* API: a single
MIX_Mixer device and MIX_Track, MIX_LoadAudio for songs, MIX_PlayTrack
with the MIX_PROP_PLAY_LOOPS_NUMBER property for looping, MIX_SetTrackGain
for volume and MIX_GetTrackPlaybackPosition for the substitute-music loop
points (replacing the removed post-mix effect callback).

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 src/i_sdlmusic.c | 107 ++++++++++++++++++++++++-----------------------
 1 file changed, 55 insertions(+), 52 deletions(-)

--- a/src/i_sdlmusic.c
+++ b/src/i_sdlmusic.c
@@ -119,12 +119,13 @@ static char *temp_timidity_cfg = NULL;
 static boolean playing_substitute = false;
 static file_metadata_t file_metadata;
 
-// Position (in samples) that we have reached in the current track.
-// This is updated by the TrackPositionCallback function.
-static unsigned int current_track_pos;
+// SDL3_mixer mixer device and the single track used for music playback.
+static MIX_Mixer *music_mixer = NULL;
+static MIX_Track *music_track = NULL;
+static int music_freq = 44100;
 
 // Currently playing music track.
-static Mix_Music *current_track_music = NULL;
+static MIX_Audio *current_track_music = NULL;
 
 // If true, the currently playing track is being played on loop.
 static boolean current_track_loop;
@@ -852,12 +853,16 @@ static void I_SDL_ShutdownMusic(void)
 {
     if (music_initialized)
     {
-        Mix_HaltMusic();
+        MIX_StopTrack(music_track, 0);
         music_initialized = false;
 
         if (sdl_was_initialized)
         {
-            Mix_CloseAudio();
+            MIX_DestroyTrack(music_track);
+            music_track = NULL;
+            MIX_DestroyMixer(music_mixer);
+            music_mixer = NULL;
+            MIX_Quit();
             SDL_QuitSubSystem(SDL_INIT_AUDIO);
             sdl_was_initialized = false;
         }
@@ -866,17 +871,7 @@ static void I_SDL_ShutdownMusic(void)
 
 static boolean SDLIsInitialized(void)
 {
-    int freq, channels;
-    SDL_AudioFormat format;
-
-    return Mix_QuerySpec(&freq, &format, &channels) != 0;
-}
-
-// Callback function that is invoked to track current track position.
-void TrackPositionCallback(int chan, void *stream, int len, void *udata)
-{
-    // Position is doubled up twice: for 16-bit samples and for stereo.
-    current_track_pos += len / 4;
+    return music_mixer != NULL;
 }
 
 // Initialize music subsystem
@@ -928,20 +923,29 @@ static boolean I_SDL_InitMusic(void)
     }
     else
     {
-        const SDL_AudioSpec spec = {SDL_AUDIO_S16, 2, 1024};
+        const SDL_AudioSpec spec = {SDL_AUDIO_S16, 2, 44100};
         if (!SDL_Init(SDL_INIT_AUDIO))
         {
             fprintf(stderr, "Unable to set up sound.\n");
         }
-        else if (!Mix_OpenAudio(0, &spec))
+        else if (!MIX_Init())
         {
-            fprintf(stderr, "Error initializing SDL_mixer: %s\n",
+            fprintf(stderr, "Error initializing SDL3_mixer: %s\n",
                     SDL_GetError());
             SDL_QuitSubSystem(SDL_INIT_AUDIO);
         }
+        else if (!(music_mixer = MIX_CreateMixerDevice(
+                       SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &spec)))
+        {
+            fprintf(stderr, "Error initializing SDL3_mixer: %s\n",
+                    SDL_GetError());
+            MIX_Quit();
+            SDL_QuitSubSystem(SDL_INIT_AUDIO);
+        }
         else
         {
-            Mix_PauseAudio(0);
+            music_track = MIX_CreateTrack(music_mixer);
+            music_freq = spec.freq;
 
             sdl_was_initialized = true;
             music_initialized = true;
@@ -961,9 +965,6 @@ static boolean I_SDL_InitMusic(void)
         fprintf(stderr, "SDL3_Mixer does not support external music playback.\n");
     }
 
-    // Register an effect function to track the music position.
-    Mix_RegisterEffect(MIX_CHANNEL_POST, TrackPositionCallback, NULL, NULL);
-
     // If we're in GENMIDI mode, try to load sound packs.
     if (snd_musicdevice == SNDDEVICE_GENMIDI)
     {
@@ -980,18 +981,18 @@ static boolean I_SDL_InitMusic(void)
 
 static void UpdateMusicVolume(void)
 {
-    int vol;
+    float gain;
 
     if (musicpaused)
     {
-        vol = 0;
+        gain = 0.0f;
     }
     else
     {
-        vol = (current_music_volume * MIX_MAX_VOLUME) / 127;
+        gain = (float) current_music_volume / 127.0f;
     }
 
-    Mix_VolumeMusic(vol);
+    MIX_SetTrackGain(music_track, gain);
 }
 
 // Set music volume (0 - 127)
@@ -1020,7 +1021,7 @@ static void I_SDL_PlaySong(void *handle,
         return;
     }
 
-    current_track_music = (Mix_Music *) handle;
+    current_track_music = (MIX_Audio *) handle;
     current_track_loop = looping;
 
     if (looping)
@@ -1029,18 +1030,23 @@ static void I_SDL_PlaySong(void *handle,
     }
     else
     {
-        loops = 1;
+        loops = 0;
     }
 
     // Don't loop when playing substitute music, as we do it
     // ourselves instead.
     if (playing_substitute && file_metadata.valid)
     {
-        loops = 1;
-        current_track_pos = 0;  // start of track
+        loops = 0;
     }
 
-    Mix_PlayMusic(current_track_music, loops);
+    {
+        SDL_PropertiesID opts = SDL_CreateProperties();
+        SDL_SetNumberProperty(opts, MIX_PROP_PLAY_LOOPS_NUMBER, loops);
+        MIX_SetTrackAudio(music_track, current_track_music);
+        MIX_PlayTrack(music_track, opts);
+        SDL_DestroyProperties(opts);
+    }
 }
 
 static void I_SDL_PauseSong(void)
@@ -1074,14 +1080,14 @@ static void I_SDL_StopSong(void)
         return;
     }
 
-    Mix_HaltMusic();
+    MIX_StopTrack(music_track, 0);
     playing_substitute = false;
     current_track_music = NULL;
 }
 
 static void I_SDL_UnRegisterSong(void *handle)
 {
-    Mix_Music *music = (Mix_Music *) handle;
+    MIX_Audio *music = (MIX_Audio *) handle;
 
     if (!music_initialized)
     {
@@ -1093,7 +1099,7 @@ static void I_SDL_UnRegisterSong(void *h
         return;
     }
 
-    Mix_FreeMusic(music);
+    MIX_DestroyAudio(music);
 }
 
 // Determine whether memory block is a .mid file 
@@ -1132,7 +1138,7 @@ static boolean ConvertMus(byte *musdata,
 static void *I_SDL_RegisterSong(void *data, int len)
 {
     char *filename;
-    Mix_Music *music;
+    MIX_Audio *music;
 
     if (!music_initialized)
     {
@@ -1146,7 +1152,7 @@ static void *I_SDL_RegisterSong(void *da
 
     if (filename != NULL)
     {
-        music = Mix_LoadMUS(filename);
+        music = MIX_LoadAudio(music_mixer, filename, false);
 
         if (music == NULL)
         {
@@ -1185,7 +1191,7 @@ static void *I_SDL_RegisterSong(void *da
     // by now, but Mix_SetMusicCMD() only works with Mix_LoadMUS(), so
     // we have to generate a temporary file.
 
-    music = Mix_LoadMUS(filename);
+    music = MIX_LoadAudio(music_mixer, filename, false);
 
     if (music == NULL)
     {
@@ -1217,19 +1223,13 @@ static boolean I_SDL_MusicIsPlaying(void
         return false;
     }
 
-    return Mix_PlayingMusic();
+    return MIX_TrackPlaying(music_track);
 }
 
 // Get position in substitute music track, in seconds since start of track.
 static double GetMusicPosition(void)
 {
-    unsigned int music_pos;
-    int freq;
-
-    Mix_QuerySpec(&freq, NULL, NULL);
-    music_pos = current_track_pos;
-
-    return (double) music_pos / freq;
+    return (double) MIX_GetTrackPlaybackPosition(music_track) / music_freq;
 }
 
 static void RestartCurrentTrack(void)
@@ -1244,15 +1244,18 @@ static void RestartCurrentTrack(void)
         // If the track finished we need to restart it.
         if (current_track_music != NULL)
         {
-            Mix_PlayMusic(current_track_music, 1);
+            SDL_PropertiesID opts = SDL_CreateProperties();
+            SDL_SetNumberProperty(opts, MIX_PROP_PLAY_LOOPS_NUMBER, 0);
+            MIX_SetTrackAudio(music_track, current_track_music);
+            MIX_PlayTrack(music_track, opts);
+            SDL_DestroyProperties(opts);
         }
 
-        Mix_SetMusicPosition(start);
-        current_track_pos = file_metadata.start_time;
+        MIX_SetTrackPlaybackPosition(music_track, (Sint64) (start * music_freq));
     }
     else
     {
-        Mix_HaltMusic();
+        MIX_StopTrack(music_track, 0);
         current_track_music = NULL;
         playing_substitute = false;
     }
@@ -1274,7 +1277,7 @@ static void I_SDL_PollMusic(void)
         }
 
         // Have we reached the actual end of track (not loop end)?
-        if (!Mix_PlayingMusic() && current_track_loop)
+        if (!MIX_TrackPlaying(music_track) && current_track_loop)
         {
             RestartCurrentTrack();
         }