add SFX access function

jpcima · Oct 16, 2019 · 1e08d36 · 1e08d36
1 parent e31f280
commit 1e08d36
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Showing 3 changed files with 38 additions and 2 deletions.
diff --git a/sources/dunelegacy/FileClasses/adl/sound_adlib.cpp b/sources/dunelegacy/FileClasses/adl/sound_adlib.cpp
@@ -2534,8 +2534,9 @@ Mix_Chunk* SoundAdlibPC::getSubsong(int Num) {
         SoundAdlibPC::callback(this, buf + bufSize - 1024, 1024);
 
         bSilent = true;
-        for(Uint8* p = buf + bufSize - 1024; p < buf + bufSize; p++) {
-            if(*p != 0) {
+        for(Sint16* p = (Sint16 *)(buf + bufSize - 1024); p < (Sint16 *)(buf + bufSize); p++) {
+            /* prudence against OPL emulators which produce ±1 in silent state */
+            if(std::abs(*p) > 1) {
                 bSilent = false;
                 break;
             }

diff --git a/sources/dunemusic.cpp b/sources/dunemusic.cpp
@@ -64,6 +64,38 @@ void DuneMusic_ChangeMusicEx(DuneMusicType musicType, const char *filename, int
     sPlayer->changeMusicEx((MUSICTYPE)musicType, filename, musicNum);
 }
 
+DUNEMUSIC_EXPORT
+int16_t *DuneMusic_SynthesizeAudio(const char *filename, int musicNum, int volume, size_t *numFramesReturned)
+{
+    sdl2::RWops_ptr rwop = pFileManager->openFile(filename);
+    if (!rwop)
+        return nullptr;
+
+    std::unique_ptr<SoundAdlibPC> adlib{new SoundAdlibPC(rwop.get())};
+
+    if (volume < 0)
+        volume = 64;
+
+    adlib->setVolume(volume);
+
+    sdl2::mix_chunk_ptr chunk{adlib->getSubsong(musicNum)};
+    if (!chunk)
+        return nullptr;
+
+    chunk->allocated = 0;
+
+    if (numFramesReturned)
+        *numFramesReturned = chunk->alen / (2 * sizeof(int16_t));
+
+    return (int16_t *)chunk->abuf;
+}
+
+DUNEMUSIC_EXPORT
+void DuneMusic_FreeAudio(int16_t *audioBuffer)
+{
+    SDL_free(audioBuffer);
+}
+
 DUNEMUSIC_EXPORT
 int DuneMusic_IsMusicEnabled()
 {

diff --git a/sources/dunemusic.h b/sources/dunemusic.h
@@ -49,6 +49,9 @@ typedef enum DuneMusicType {
 void DuneMusic_ChangeMusic(DuneMusicType musicType);
 void DuneMusic_ChangeMusicEx(DuneMusicType musicType, const char *filename, int musicNum);
 
+int16_t *DuneMusic_SynthesizeAudio(const char *filename, int musicNum, int volume, size_t *numFramesReturned);
+void DuneMusic_FreeAudio(int16_t *audioBuffer);
+
 int DuneMusic_IsMusicEnabled();
 void DuneMusic_SetMusicEnabled(int enabled);
 int DuneMusic_IsMusicPlaying();