refactor SDL audio a little and add support for music volume adjustment

1 files changed, 33 insertions, 23 deletions

diff --git a/src/library_sdl.js b/src/library_sdl.js
index 7338f215..6575c334 100644
--- a/src/library_sdl.js
+++ b/src/library_sdl.js
@@ -16,9 +16,14 @@ var LibrarySDL = {
 
     surfaces: {},
     events: [],
-    audios: [null],
     fonts: [null],
 
+    audios: [null],
+    music: {
+      audio: null,
+      volume: 1.0
+    },
+
     keyboardState: null,
     shiftKey: false,
     ctrlKey: false,
@@ -485,6 +490,16 @@ var LibrarySDL = {
       }
     },
 
+    setGetVolume: function(info, volume) {
+      if (!info) return 0;
+      var ret = info.volume * 128; // MIX_MAX_VOLUME
+      if (volume != -1) {
+        info.volume = volume / 128;
+        if (info.audio) info.audio.volume = info.volume;
+      }
+      return ret;
+    },
+
     // Debugging
 
     debugSurface: function(surfData) {
@@ -1058,13 +1073,7 @@ var LibrarySDL = {
       }
       return _Mix_Volume(SDL.numChannels-1, volume);
     }
-    var info = SDL.channels[channel];
-    var ret = info.volume * 128;
-    if (volume != -1) {
-      info.volume = volume / 128;
-      if (info.audio) info.audio.volume = info.volume;
-    }
-    return ret;
+    return SDL.setGetVolume(SDL.channels[channel], volume);
   },
 
   Mix_SetPanning: function() {
@@ -1135,13 +1144,13 @@ var LibrarySDL = {
   Mix_HookMusicFinished__deps: ['Mix_HaltMusic'],
   Mix_HookMusicFinished: function(func) {
     SDL.hookMusicFinished = func;
-    if (SDL.music) { // ensure the callback will be called, if a music is already playing
-      SDL.music['onended'] = _Mix_HaltMusic;
+    if (SDL.music.audio) { // ensure the callback will be called, if a music is already playing
+      SDL.music.audio['onended'] = _Mix_HaltMusic;
     }
   },
 
-  Mix_VolumeMusic: function(func) {
-    return 0; // TODO
+  Mix_VolumeMusic: function(volume) {
+    return SDL.setGetVolume(SDL.music, volume);
   },
 
   Mix_LoadMUS: 'Mix_LoadWAV_RW',
@@ -1155,31 +1164,32 @@ var LibrarySDL = {
     if (!audio) return 0;
     audio.loop = loops != 1; // TODO: handle N loops for finite N
     audio.play();
+    audio.volume = SDL.music.volume;
     audio['onended'] = _Mix_HaltMusic; // will send callback
-    SDL.music = audio;
+    SDL.music.audio = audio;
     return 0;
   },
 
-  Mix_PauseMusic: function(id) {
-    var audio = SDL.audios[id];
+  Mix_PauseMusic: function() {
+    var audio = SDL.music.audio;
     if (!audio) return 0;
-    audio.audio.pause();
+    audio.pause();
     return 0;
   },
 
-  Mix_ResumeMusic: function(id) {
-    var audio = SDL.audios[id];
+  Mix_ResumeMusic: function() {
+    var audio = SDL.music.audio;
     if (!audio) return 0;
-    audio.audio.play();
+    audio.play();
     return 0;
   },
 
   Mix_HaltMusic: function() {
-    var audio = SDL.music;
+    var audio = SDL.music.audio;
     if (!audio) return 0;
     audio.src = audio.src; // rewind
     audio.pause();
-    SDL.music = null;
+    SDL.music.audio = null;
     if (SDL.hookMusicFinished) {
       FUNCTION_TABLE[SDL.hookMusicFinished]();
     }
@@ -1191,11 +1201,11 @@ var LibrarySDL = {
   Mix_FadeOutMusic: 'Mix_HaltMusic', // XXX ignore fading out effect
 
   Mix_PlayingMusic: function() {
-    return (SDL.music && !SDL.music.paused) ? 1 : 0;
+    return (SDL.music.audio && !SDL.music.audio.paused) ? 1 : 0;
   },
 
   Mix_PausedMusic: function() {
-    return (SDL.music && SDL.music.paused) ? 1 : 0;
+    return (SDL.music.audio && SDL.music.audio.paused) ? 1 : 0;
   },
 
   // SDL TTF