Add config option for volume scale

mkxp.json

@@ -467,6 +467,16 @@
     //
     // "YJITEnable": false,
 
+    // Determines how the volume value of a sound affects how loud the sound is.
+    // The stock RPG Maker runtimes use a 35 dB scale for volume (option 1),
+    // but other runtimes might use a different scale.
+    // 0: linear (sound amplitude is multiplied by the volume)
+    // 1: 35 dB (a gain of -0.35 dB is applied to the sound for every percent
+    //           the volume is set below 100%)
+    // (default: 1)
+    //
+    // "volumeScale": 1,
+
     // SoundFont to use for midi playback (via fluidsynth)
     // (default: none)
     //

src/audio/al-util.h

@@ -170,20 +170,20 @@ namespace Source
 
 	enum VolumeScale
 	{
-		Linear,
+		Linear = 0,
-		Db35,
+		Db35 = 1,
 	};
 
 	inline void setVolume(Source::ID id, float value, VolumeScale scale)
 	{
 		switch (scale) {
-			case VolumeScale::Linear:
-				break;
 			case VolumeScale::Db35:
 				if (value > FLT_EPSILON) {
 					value = std::powf(10.0f, -(35.0f / 20.0f) * (1.0f - value));
 				}
 				break;
+			default:
+				break;
 		}
 		alSourcef(id.al, AL_GAIN, value * 0.8f);
 	}

src/audio/alstream.cpp

@@ -36,9 +36,11 @@
 #include <SDL_timer.h>
 
 ALStream::ALStream(LoopMode loopMode,
+		           AL::Source::VolumeScale volumeScale,
 		           const std::string &threadId)
 	: looped(loopMode == Looped),
 	  state(Closed),
+	  volumeScale(volumeScale),
 	  source(0),
 	  thread(0),
 	  preemptPause(false),
@@ -46,7 +48,7 @@ ALStream::ALStream(LoopMode loopMode,
 {
 	alSrc = AL::Source::gen();
 
-	AL::Source::setVolume(alSrc, 1.0f, AL::Source::Linear);
+	AL::Source::setVolume(alSrc, 1.0f, volumeScale);
 	AL::Source::setPitch(alSrc, 1.0f);
 	AL::Source::detachBuffer(alSrc);
 
@@ -164,7 +166,7 @@ void ALStream::pause()
 
 void ALStream::setVolume(float value)
 {
-	AL::Source::setVolume(alSrc, value, AL::Source::Linear);
+	AL::Source::setVolume(alSrc, value, volumeScale);
 }
 
 void ALStream::setPitch(float value)

src/audio/alstream.h

@@ -47,6 +47,8 @@ struct ALStream
 	bool looped;
 	State state;
 
+	AL::Source::VolumeScale volumeScale;
+
 	ALDataSource *source;
 	SDL_Thread *thread;
 
@@ -89,6 +91,7 @@ struct ALStream
 	};
 
 	ALStream(LoopMode loopMode,
+	         AL::Source::VolumeScale volumeScale,
 	         const std::string &threadId);
 	~ALStream();
 

src/audio/audio.cpp

@@ -69,15 +69,15 @@ struct AudioPrivate
 	} meWatch;
 
 	AudioPrivate(RGSSThreadData &rtData)
-	    : bgs(ALStream::Looped, "bgs"),
+	    : bgs(ALStream::Looped, static_cast<AL::Source::VolumeScale>(rtData.config.volumeScale), "bgs"),
-	      me(ALStream::NotLooped, "me"),
+	      me(ALStream::NotLooped, static_cast<AL::Source::VolumeScale>(rtData.config.volumeScale), "me"),
 	      se(rtData.config),
 	      syncPoint(rtData.syncPoint),
           volumeRatio(1)
 	{
         for (int i = 0; i < rtData.config.BGM.trackCount; i++) {
             std::string id = std::string("bgm" + std::to_string(i));
-            bgmTracks.push_back(new AudioStream(ALStream::Looped, id.c_str()));
+            bgmTracks.push_back(new AudioStream(ALStream::Looped, static_cast<AL::Source::VolumeScale>(rtData.config.volumeScale), id.c_str()));
         }
         
 		meWatch.state = MeNotPlaying;

src/audio/audiostream.cpp

@@ -29,10 +29,11 @@
 #include <SDL_timer.h>
 
 AudioStream::AudioStream(ALStream::LoopMode loopMode,
+                         AL::Source::VolumeScale volumeScale,
                          const std::string &threadId)
 	: extPaused(false),
 	  noResumeStop(false),
-	  stream(loopMode, threadId)
+	  stream(loopMode, volumeScale, threadId)
 {
 	current.volume = 1.0f;
 	current.pitch = 1.0f;

src/audio/audiostream.h

@@ -121,6 +121,7 @@ struct AudioStream
 	} fadeIn;
 
 	AudioStream(ALStream::LoopMode loopMode,
+	            AL::Source::VolumeScale volumeScale,
 	            const std::string &threadId);
 	~AudioStream();
 

src/audio/soundemitter.cpp

@@ -93,7 +93,8 @@ SoundEmitter::SoundEmitter(const Config &conf)
       srcCount(conf.SE.sourceCount),
       alSrcs(srcCount),
       atchBufs(srcCount),
-      srcPrio(srcCount)
+      srcPrio(srcCount),
+      volumeScale(static_cast<AL::Source::VolumeScale>(conf.volumeScale))
 {
 	for (size_t i = 0; i < srcCount; ++i)
 	{
@@ -172,7 +173,7 @@ void SoundEmitter::play(const std::string &filename,
 	if (switchBuffer)
 		AL::Source::attachBuffer(src, buffer->alBuffer);
 
-	AL::Source::setVolume(src, _volume, AL::Source::Linear);
+	AL::Source::setVolume(src, _volume, volumeScale);
 	AL::Source::setPitch(src, _pitch);
 
 	AL::Source::play(src);

src/audio/soundemitter.h

@@ -49,6 +49,8 @@ struct SoundEmitter
 	/* Indices of sources, sorted by priority (lowest first) */
 	std::vector<size_t> srcPrio;
 
+	AL::Source::VolumeScale volumeScale;
+
 	SoundEmitter(const Config &conf);
 	~SoundEmitter();
 

src/config.cpp

@@ -178,6 +178,7 @@ void Config::read(int argc, char *argv[]) {
         {"dataPathApp", ""},
         {"iconPath", ""},
         {"execName", "Game"},
+        {"volumeScale", 1},
         {"midiSoundFont", ""},
         {"midiChorus", false},
         {"midiReverb", false},
@@ -306,6 +307,7 @@ try { exp } catch (...) {}
     SET_OPT(anyAltToggleFS, boolean);
     SET_OPT(enableReset, boolean);
     SET_OPT(enableSettings, boolean);
+    SET_OPT(volumeScale, integer);
     SET_STRINGOPT(midi.soundFont, midiSoundFont);
     SET_OPT_CUSTOMKEY(midi.chorus, midiChorus, boolean);
     SET_OPT_CUSTOMKEY(midi.reverb, midiReverb, boolean);

src/config.h

@@ -22,6 +22,7 @@
 #ifndef CONFIG_H
 #define CONFIG_H
 
+#include "al-util.h"
 #include "util/json5pp.hpp"
 
 #include <set>
@@ -93,6 +94,8 @@ struct Config {
     std::string execName;
     std::string titleLanguage;
     
+    int volumeScale;
+    
     struct {
         std::string soundFont;
         bool chorus;