Fixed looping behavior and Mix_Playing() result for looping channels

Lee Salzman If you passed in a negative loop count, it is supposed to behave as if it loops forever. However, it blindly decrements the loop counter regardless of whether or not the loop count is actually positive. So first fix is just to put a > 0 guard before the loop counter decrement. The second fix is that Mix_Playing somehow checked only for looping > 0, so it ignored negative loop counts entirely, which just seems like a bug too. This has prevented me from using Mix_Playing internally in my engine if only because it never actually worked with looping. Mix_PlayingMusic oddly does it correctly and checks for non-zero.
libsdl-org · Jul 9, 2013 · ddd2310 · ddd2310
1 parent befbaff
commit ddd2310
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Showing 4 changed files with 14 additions and 7 deletions.
diff --git a/mixer.c b/mixer.c
@@ -385,13 +385,17 @@ static void mix_channels(void *udata, Uint8 *stream, int len)
                     if (mix_input != mix_channel[i].chunk->abuf)
                         SDL_free(mix_input);
 
-                    --mix_channel[i].looping;
+                    if (mix_channel[i].looping > 0) {
+                        --mix_channel[i].looping;
+                    }
                     mix_channel[i].samples = mix_channel[i].chunk->abuf + remaining;
                     mix_channel[i].playing = mix_channel[i].chunk->alen - remaining;
                     index += remaining;
                 }
                 if ( ! mix_channel[i].playing && mix_channel[i].looping ) {
-                    --mix_channel[i].looping;
+                    if (mix_channel[i].looping > 0) {
+                        --mix_channel[i].looping;
+                    }
                     mix_channel[i].samples = mix_channel[i].chunk->abuf;
                     mix_channel[i].playing = mix_channel[i].chunk->alen;
                 }
@@ -1111,14 +1115,14 @@ int Mix_Playing(int which)
 
         for ( i=0; i<num_channels; ++i ) {
             if ((mix_channel[i].playing > 0) ||
-                (mix_channel[i].looping > 0))
+                mix_channel[i].looping)
             {
                 ++status;
             }
         }
     } else if ( which < num_channels ) {
         if ( (mix_channel[which].playing > 0) ||
-             (mix_channel[which].looping > 0) )
+             mix_channel[which].looping )
         {
             ++status;
         }

diff --git a/music.c b/music.c
@@ -210,7 +210,9 @@ static int music_halt_or_loop (void)
         if (music_loops)
         {
             Mix_Fading current_fade;
-            --music_loops;
+            if (music_loops > 0) {
+                --music_loops;
+            }
             current_fade = music_playing->fading;
             music_internal_play(music_playing, 0.0);
             music_playing->fading = current_fade;

diff --git a/native_midi/native_midi_haiku.cpp b/native_midi/native_midi_haiku.cpp
@@ -71,7 +71,7 @@ class MidiEventsStore : public BMidi
     {
       if (!ev) {
         if (fLoops && fEvs) {
-          --fLoops;
+          if (fLoops > 0) --fLoops;
           fPos = 0;
           ev = fEvs;
         } else

diff --git a/native_midi/native_midi_win32.c b/native_midi/native_midi_win32.c
@@ -175,7 +175,8 @@ void CALLBACK MidiProc( HMIDIIN hMidi, UINT uMsg, DWORD_PTR dwInstance,
     case MOM_POSITIONCB:
       if ((currentsong->MusicLoaded) && (dwParam1 == (DWORD_PTR)&currentsong->MidiStreamHdr[currentsong->CurrentHdr])) {
         if (currentsong->Loops) {
-          --currentsong->Loops;
+          if (currentsong->Loops > 0)
+            --currentsong->Loops;
           currentsong->NewPos=0;
           BlockOut(currentsong);
         } else {