Add volume control to battle music

Battle music volume is set based on the music volume slider in the
Minecraft settings. The default Midi device provided in Java does not
appear to support changing the volume of playing midi file after some
testing. For now, only ".wav" files obey the Music volume slider
settings.

src/main/java/com/seodisparate/TurnBasedMinecraft/client/BattleMusic.java

@@ -10,6 +10,7 @@ import javax.sound.midi.MidiSystem;
 import javax.sound.midi.Sequencer;
 import javax.sound.sampled.AudioSystem;
 import javax.sound.sampled.Clip;
+import javax.sound.sampled.FloatControl;
 import javax.sound.sampled.LineUnavailableException;
 
 import org.apache.logging.log4j.Logger;
@@ -119,10 +120,10 @@ public class BattleMusic
             sillyMusic.add(f);
         }
         
+        initialized = true;
+        
         pickNextBattle();
         pickNextSilly();
-        
-        initialized = true;
     }
     
     private void pickNextBattle()
@@ -145,32 +146,41 @@ public class BattleMusic
         nextSilly = sillyMusic.get((int)(Math.random() * sillyMusic.size()));
     }
     
-    public void playBattle()
+    public void playBattle(float volume)
     {
-        if(!initialized)
+        if(!initialized || volume <= 0.0f)
         {
             return;
         }
-        play(nextBattle);
+        else if(volume > 1.0f)
+        {
+            volume = 1.0f;
+        }
+        play(nextBattle, volume);
         pickNextBattle();
         playingIsSilly = false;
     }
     
-    public void playSilly()
+    public void playSilly(float volume)
     {
-        if(!initialized)
+        if(!initialized || volume <= 0.0f)
         {
             return;
         }
-        play(nextSilly);
+        else if(volume > 1.0f)
+        {
+            volume = 1.0f;
+        }
+        play(nextSilly, volume);
         pickNextSilly();
         playingIsSilly = true;
     }
     
-    private void play(File next)
+    private void play(File next, float volume)
     {
         if(initialized && next != null)
         {
+            logger.debug("play called with file " + next.getName() + " and vol " + volume);
             Minecraft.getMinecraft().addScheduledTask(() -> {
                 Minecraft.getMinecraft().getSoundHandler().pauseSounds();
             });
@@ -193,6 +203,7 @@ public class BattleMusic
                     logger.error("Failed to play battle music (midi)");
                     return;
                 }
+                
                 sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);
                 sequencer.start();
             }
@@ -215,6 +226,11 @@ public class BattleMusic
                     logger.error("Failed to load battle music (wav)");
                     return;
                 }
+                
+                // set volume
+                FloatControl gainControl = (FloatControl) clip.getControl(FloatControl.Type.MASTER_GAIN);
+                gainControl.setValue(volume * 20.0f - 20.0f); // in decibels
+                
                 clip.loop(Clip.LOOP_CONTINUOUSLY);
                 clip.start();
             }

src/main/java/com/seodisparate/TurnBasedMinecraft/client/ClientProxy.java

@@ -8,6 +8,7 @@ import com.seodisparate.TurnBasedMinecraft.common.TurnBasedMinecraftMod;
 
 import net.minecraft.client.Minecraft;
 import net.minecraft.entity.Entity;
+import net.minecraft.util.SoundCategory;
 import net.minecraft.util.text.TextComponentString;
 
 public class ClientProxy extends CommonProxy
@@ -92,13 +93,13 @@ public class ClientProxy extends CommonProxy
     @Override
     public void playBattleMusic()
     {
-        battleMusic.playBattle();
+        battleMusic.playBattle(Minecraft.getMinecraft().gameSettings.getSoundLevel(SoundCategory.MUSIC));
     }
 
     @Override
     public void playSillyMusic()
     {
-        battleMusic.playSilly();
+        battleMusic.playSilly(Minecraft.getMinecraft().gameSettings.getSoundLevel(SoundCategory.MUSIC));
     }
 
     @Override