clean up stuff + add multitrack setting to json

binding/audio-binding.cpp

@@ -92,34 +92,36 @@ RB_METHOD(audio_bgmPlay)
     int volume = 100;
     int pitch = 100;
     double pos = 0.0;
-    int channel = -127;
-    rb_get_args(argc, argv, "z|iifi", &filename, &volume, &pitch, &pos, &channel RB_ARG_END);
-    GUARD_EXC( shState->audio().bgmPlay(filename, volume, pitch, pos, channel); )
+    int track = -127;
+    rb_get_args(argc, argv, "z|iifi", &filename, &volume, &pitch, &pos, &track RB_ARG_END);
+    GUARD_EXC( shState->audio().bgmPlay(filename, volume, pitch, pos, track); )
     return Qnil;
 }
 
 RB_METHOD(audio_bgmStop)
 {
     RB_UNUSED_PARAM;
-    int channel = -127;
-    rb_get_args(argc, argv, "|i", &channel RB_ARG_END);
-    shState->audio().bgmStop(channel);
+    int track = -127;
+    rb_get_args(argc, argv, "|i", &track RB_ARG_END);
+    shState->audio().bgmStop(track);
     return Qnil;
 }
 
 RB_METHOD(audio_bgmPos)
 {
     RB_UNUSED_PARAM;
-    return rb_float_new(shState->audio().bgmPos());
+    int track = 0;
+    rb_get_args(argc, argv, "|i", &track RB_ARG_END);
+    return rb_float_new(shState->audio().bgmPos(track));
 }
 
 RB_METHOD(audio_bgmGetVolume)
 {
     RB_UNUSED_PARAM;
-    int channel = -127;
-    rb_get_args(argc, argv, "|i", &channel RB_ARG_END);
+    int track = -127;
+    rb_get_args(argc, argv, "|i", &track RB_ARG_END);
     int ret = 0;
-    GUARD_EXC( ret = shState->audio().bgmGetVolume(); )
+    GUARD_EXC( ret = shState->audio().bgmGetVolume(track); )
     return rb_fix_new(ret);
 }
 
@@ -127,9 +129,9 @@ RB_METHOD(audio_bgmSetVolume)
 {
     RB_UNUSED_PARAM;
     int volume;
-    int channel = -127;
-    rb_get_args(argc, argv, "i|i", &volume, &channel RB_ARG_END);
-    GUARD_EXC( shState->audio().bgmSetVolume(volume, channel); )
+    int track = -127;
+    rb_get_args(argc, argv, "i|i", &volume, &track RB_ARG_END);
+    GUARD_EXC( shState->audio().bgmSetVolume(volume, track); )
     return Qnil;
 }
 
@@ -142,9 +144,9 @@ RB_METHOD(audio_bgmFade)
 {
     RB_UNUSED_PARAM;
     int time;
-    int channel = -127;
-    rb_get_args(argc, argv, "i|i", &time, &channel RB_ARG_END);
-    shState->audio().bgmFade(time, channel);
+    int track = -127;
+    rb_get_args(argc, argv, "i|i", &time, &track RB_ARG_END);
+    shState->audio().bgmFade(time, track);
     return Qnil;
 }
 

mkxp.json

@@ -372,6 +372,12 @@
     // this number. Maximum: 64.
     //
     // "SESourceCount": 6
+    
+    // Number of streams to open for BGM tracks. If the game
+    // needs multitrack audio, this should be set to as many
+    // available tracks as the game needs. Maximum: 16.
+    //
+    // "BGMTrackCount": 1
 
 
     // The Windows game executable name minus ".exe". By default

src/audio/audio.cpp

@@ -27,6 +27,7 @@
 #include "sharedmidistate.h"
 #include "eventthread.h"
 #include "sdl-util.h"
+#include "exception.h"
 
 #include <string>
 #include <vector>
@@ -37,9 +38,6 @@
 struct AudioPrivate
 {
     
-    // mkxp-z manages multiple streams of BGM.
-    // play/pause states should be shared between them, so checking the state of the first
-    // one should be enough to know what the rest are doing.
     std::vector<AudioStream*> bgmTracks;
 	AudioStream bgs;
 	AudioStream me;
@@ -94,6 +92,14 @@ struct AudioPrivate
         for (auto track : bgmTracks)
             delete track;
 	}
+    
+    AudioStream *getTrackByIndex(int index) {
+        if (index < 0) index = 0;
+        if (index > bgmTracks.size() - 1) {
+            throw Exception(Exception::MKXPError, "requested BGM track %d out of range (max: %d)", index, bgmTracks.size() - 1);
+        }
+        return bgmTracks[index];
+    }
 
 	void meWatchFun()
 	{
@@ -287,60 +293,59 @@ void Audio::bgmPlay(const char *filename,
                     int volume,
                     int pitch,
                     float pos,
-                    int channel)
+                    int track)
 {
-    if (channel == -127) {
+    if (track == -127) {
         for (auto track : p->bgmTracks)
             track->stop();
         
-        channel = 0;
+        track = 0;
     }
-	p->bgmTracks[clamp(channel, 0, (int)p->bgmTracks.size() - 1)]->play(filename, volume, pitch, pos);
+	p->getTrackByIndex(track)->play(filename, volume, pitch, pos);
 }
 
-void Audio::bgmStop(int channel)
+void Audio::bgmStop(int track)
 {
-    if (channel == -127) {
+    if (track == -127) {
         for (auto track : p->bgmTracks)
             track->stop();
         
         return;
     }
     
-    p->bgmTracks[clamp(channel, 0, (int)p->bgmTracks.size() - 1)]->stop();
+    p->getTrackByIndex(track)->stop();
 }
 
-void Audio::bgmFade(int time, int channel)
+void Audio::bgmFade(int time, int track)
 {
-    if (channel == -127) {
+    if (track == -127) {
         for (auto track : p->bgmTracks)
             track->fadeOut(time);
         
         return;
     }
     
-    p->bgmTracks[clamp(channel, 0, (int)p->bgmTracks.size() - 1)]->fadeOut(time);
+    p->getTrackByIndex(track)->fadeOut(time);
 }
 
-int Audio::bgmGetVolume(int channel)
+int Audio::bgmGetVolume(int track)
 {
-    if (channel == -127)
-        return p->bgmTracks[channel]->getVolume(AudioStream::BaseRatio) * 100;
+    if (track == -127)
+        return p->bgmTracks[0]->getVolume(AudioStream::BaseRatio) * 100;
     
-    return p->bgmTracks[channel]->getVolume(AudioStream::Base) * 100;
+    return p->getTrackByIndex(track)->getVolume(AudioStream::Base) * 100;
 }
 
-void Audio::bgmSetVolume(int volume, int channel)
+void Audio::bgmSetVolume(int volume, int track)
 {
     float vol = volume / 100.0;
-    if (channel == -127) {
+    if (track == -127) {
         for (auto track : p->bgmTracks)
             track->setVolume(AudioStream::BaseRatio, vol);
         
         return;
     }
-    channel = clamp(channel, 0, (int)p->bgmTracks.size() - 1);
-    p->bgmTracks[channel]->setVolume(AudioStream::Base, vol);
+    p->getTrackByIndex(track)->setVolume(AudioStream::Base, vol);
 }
 
 
@@ -398,9 +403,9 @@ void Audio::setupMidi()
 	shState->midiState().initIfNeeded(shState->config());
 }
 
-float Audio::bgmPos()
+float Audio::bgmPos(int track)
 {
-	return p->bgmTracks[0]->playingOffset();
+	return p->getTrackByIndex(track)->playingOffset();
 }
 
 float Audio::bgsPos()

src/audio/audio.h

@@ -42,11 +42,11 @@ public:
 	             int volume = 100,
 	             int pitch = 100,
 	             float pos = 0,
-                 int channel = -127);
-	void bgmStop(int channel = -127);
-	void bgmFade(int time, int channel = -127);
-    int bgmGetVolume(int channel = -127);
-    void bgmSetVolume(int volume = 100, int channel = -127);
+                 int track = -127);
+	void bgmStop(int track = -127);
+	void bgmFade(int time, int track = -127);
+    int bgmGetVolume(int track = -127);
+    void bgmSetVolume(int volume = 100, int track = -127);
 
 	void bgsPlay(const char *filename,
 	             int volume = 100,
@@ -67,7 +67,7 @@ public:
 	void seStop();
 
 	void setupMidi();
-	float bgmPos();
+	float bgmPos(int track = 0);
 	float bgsPos();
 
 	void reset();

src/audio/audiostream.h

@@ -42,14 +42,13 @@ struct AudioStream
 	 * Multiplied together for final
 	 * playback volume. Used with setVolume().
 	 * Base is set by play().
+     * BaseRatio is set by Audio::setVolume() when no specific channel is specified.
+       It should be identical among all BGM tracks.
 	 * External is used by MeWatch */
 	enum VolumeType
 	{
 		Base = 0,
-        
-        // BaseRatio should be identical among all BGM tracks.
         BaseRatio,
-        
 		FadeOut,
 		FadeIn,
         External,

src/config.cpp

@@ -302,6 +302,7 @@ try { exp } catch (...) {}
     
     rgssVersion = clamp(rgssVersion, 0, 3);
     SE.sourceCount = clamp(SE.sourceCount, 1, 64);
+    BGM.trackCount = clamp(BGM.trackCount, 1, 16);
     
     // Determine whether to open a console window on... Windows
     winConsole = getEnvironmentBool("MKXPZ_WINDOWS_CONSOLE", editor.debug);