From 57d5e549832741e74f542309b15145b83b5bd28b Mon Sep 17 00:00:00 2001
From: toaster <rollerorbital@gmail.com>
Date: Sun, 10 Mar 2024 12:19:31 +0000
Subject: [PATCH] Stereo Mode: Fix multi-Track musicdefs not having their first
 part loop under non-Seq conditions

Had to introduce a hacky Music_SetFadeOut func, but I didn't want to rework this section of code/menu too heavily for how little time we have left
---
 src/music.cpp | 17 +++++++++++++++++
 src/music.h   |  4 ++++
 src/s_sound.c | 25 ++++++++++++++++++-------
 3 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/src/music.cpp b/src/music.cpp
index caa77e51c..9b0de56e9 100644
--- a/src/music.cpp
+++ b/src/music.cpp
@@ -218,6 +218,23 @@ void Music_Play(const char* id)
 	}
 }
 
+void Music_SetFadeOut(const char* id, int fade_out)
+{
+	Tune* tune = g_tunes.find(id);
+
+	if (tune)
+	{
+		tune->fade_out = fade_out;
+
+		if (tune->time_remaining() <= detail::msec_to_tics(tune->fade_out))
+		{
+			// If this action would cause a fade out, start
+			// fading immediately.
+			g_tunes.tick();
+		}
+	}
+}
+
 void Music_DelayEnd(const char* id, tic_t duration)
 {
 	Tune* tune = g_tunes.find(id);
diff --git a/src/music.h b/src/music.h
index 2265639ea..61f6c4976 100644
--- a/src/music.h
+++ b/src/music.h
@@ -59,6 +59,10 @@ const char *Music_CurrentId(void);
 // back to the start.)
 void Music_Play(const char *id);
 
+// Set fade out duration. Mostly to fix a last minute bug
+// with Stereo Mode.
+void Music_SetFadeOut(const char* id, int fade_out);
+
 // Postpone the end of this tune until N tics from now. The
 // tune should already be playing before calling this.
 void Music_DelayEnd(const char *id, tic_t duration);
diff --git a/src/s_sound.c b/src/s_sound.c
index a26ad51ef..6daecbb26 100644
--- a/src/s_sound.c
+++ b/src/s_sound.c
@@ -1690,10 +1690,7 @@ const char *S_SoundTestTune(UINT8 invert)
 
 boolean S_SoundTestCanSequenceFade(void)
 {
-	return
-		soundtest.current->basenoloop[soundtest.currenttrack] == false &&
-		// Only fade out if we're the last track for this song.
-		soundtest.currenttrack == soundtest.current->numtracks-1;
+	return soundtest.current->basenoloop[soundtest.currenttrack] == false;
 }
 
 static void S_SoundTestReconfigure(const char *tune)
@@ -1728,12 +1725,16 @@ void S_SoundTestPlay(void)
 	}
 
 	// Does song have default loop?
-	if (soundtest.current->basenoloop[soundtest.currenttrack] == false)
+	if (S_SoundTestCanSequenceFade() == true)
 	{
+		// I'd personally like songs in sequence to last between 3 and 6 minutes.
 		if (sequencemaxtime < 3*60*1000)
 		{
-			// I'd personally like songs in sequence to last between 3 and 6 minutes.
-			const UINT32 loopduration = (sequencemaxtime - I_GetSongLoopPoint());
+			const UINT32 looppoint = I_GetSongLoopPoint();
+			const UINT32 loopduration =
+				(looppoint < sequencemaxtime)
+				? sequencemaxtime - looppoint
+				: 0;
 
 			if (!loopduration)
 				;
@@ -1745,6 +1746,16 @@ void S_SoundTestPlay(void)
 		}
 	}
 
+	// Only the last track fades out... but we still use stereo_fade to handle stopping.
+	if (soundtest.currenttrack == soundtest.current->numtracks-1)
+	{
+		Music_SetFadeOut("stereo_fade", 5000);
+	}
+	else
+	{
+		Music_SetFadeOut("stereo_fade", 0);
+	}
+
 	Music_DelayEnd(
 		S_SoundTestCanSequenceFade() ? "stereo_fade" : "stereo",
 		(TICRATE*sequencemaxtime)/1000 // ms to TICRATE conversion