From 763cfb01f05503fd71a27f409d9dc5fab2a3eefe Mon Sep 17 00:00:00 2001
From: Guangcong Luo <guangcongluo@gmail.com>
Date: Sun, 11 Dec 2016 05:29:21 -0500
Subject: [PATCH] Fix background music stuttering

I finally got to reading the SM2 documentation more closely, and saw:

> precision can vary between 20 msec to perhaps 0.5 seconds and the
> sound's position property will reflect this delta when the
> onPosition() callback fires

Emphasis on "this.position will reflect this delta".

Anyway, this new system should have significantly less noticeable
stuttering.
---
 js/battle.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/js/battle.js b/js/battle.js
index ffc76d51d..7ea14bac5 100644
--- a/js/battle.js
+++ b/js/battle.js
@@ -92,8 +92,8 @@ var BattleSoundLibrary = (function () {
 			// suppress crash
 			return (this.bgmCache[url] = this.soundPlaceholder);
 		}
-		this.bgmCache[url].onposition(loopend, function () {
-			this.setPosition(loopstart);
+		this.bgmCache[url].onposition(loopend, function (evP) {
+			this.setPosition(this.position - (loopend - loopstart));
 		});
 		return this.bgmCache[url];
 	};