From 86cbc5e7badec1ba562a5dfe2d3cf6a3bd0b55cf Mon Sep 17 00:00:00 2001
From: Stephen Seo <seo.disparate@gmail.com>
Date: Wed, 31 Jan 2024 11:57:52 +0900
Subject: [PATCH] Fix volume handling of battle/silly music

---
 Changelog.md                                    |  3 +++
 .../TurnBasedMinecraft/client/BattleMusic.java  | 17 ++++++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/Changelog.md b/Changelog.md
index 5f4eca2..67360eb 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,8 @@
 # Upcoming changes
 
+Fix volume handling of battle/silly music. (Previous implementation did not
+properly reduce volume based on Minecraft's "music volume" setting.)
+
 # Version NeoForge-1.25.2
 
 Fix invalid use of throwable potions. (Previously, the Player would "drink"
diff --git a/src/main/java/com/burnedkirby/TurnBasedMinecraft/client/BattleMusic.java b/src/main/java/com/burnedkirby/TurnBasedMinecraft/client/BattleMusic.java
index bccb282..601f839 100644
--- a/src/main/java/com/burnedkirby/TurnBasedMinecraft/client/BattleMusic.java
+++ b/src/main/java/com/burnedkirby/TurnBasedMinecraft/client/BattleMusic.java
@@ -259,7 +259,7 @@ public class BattleMusic
                 
                 // set volume
                 FloatControl gainControl = (FloatControl) clip.getControl(FloatControl.Type.MASTER_GAIN);
-                gainControl.setValue(volume * 20.0f - 20.0f); // in decibels
+                gainControl.setValue(BattleMusic.percentageToDecibels(volume));
 
                 clip.loop(Clip.LOOP_CONTINUOUSLY);
                 clip.start();
@@ -387,6 +387,17 @@ public class BattleMusic
         return !sillyMusic.isEmpty();
     }
 
+    /// Percentage must be between 0 and 1.
+    public static float percentageToDecibels(float percentage) {
+        if (percentage > 1.0F) {
+            return 0.0F;
+        } else if (percentage <= 0.0F) {
+            return Float.NEGATIVE_INFINITY;
+        } else {
+            return (float) (Math.log10(percentage) * 20.0);
+        }
+    }
+
     private class MP3Streamer implements Runnable
     {
         private AtomicBoolean keepPlaying;
@@ -438,7 +449,7 @@ public class BattleMusic
                 sdl.open(audioFormat);
                 {
                     FloatControl volumeControl = (FloatControl) sdl.getControl(FloatControl.Type.MASTER_GAIN);
-                    volumeControl.setValue(volume * 20.0f - 20.0f); // in decibels
+                    volumeControl.setValue(BattleMusic.percentageToDecibels(volume));
                 }
 
                 ByteArrayOutputStream baos = new ByteArrayOutputStream();
@@ -536,7 +547,7 @@ public class BattleMusic
                 sdl.open(audioFormat);
                 {
                     FloatControl volumeControl = (FloatControl) sdl.getControl(FloatControl.Type.MASTER_GAIN);
-                    volumeControl.setValue(volume * 20.0f - 20.0f); // in decibels
+                    volumeControl.setValue(BattleMusic.percentageToDecibels(volume));
                 }
 
                 AudioInputStream ais = reader.getAudioInputStream(oggVorbisFile);