From 7ff899bd22f20c53d067529140aeb466612e8bbc Mon Sep 17 00:00:00 2001
From: erorcun <erorcunerorcun@hotmail.com.tr>
Date: Tue, 2 Feb 2021 16:39:08 +0300
Subject: OAL Loops, fixes

---
 src/audio/oal/channel.cpp | 56 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 53 insertions(+), 3 deletions(-)

(limited to 'src/audio/oal/channel.cpp')

diff --git a/src/audio/oal/channel.cpp b/src/audio/oal/channel.cpp
index 673a4aed..d1fd0aea 100644
--- a/src/audio/oal/channel.cpp
+++ b/src/audio/oal/channel.cpp
@@ -15,6 +15,8 @@ ALuint alFilters[MAXCHANNELS+MAX2DCHANNELS];
 ALuint alBuffers[MAXCHANNELS+MAX2DCHANNELS];
 bool bChannelsCreated = false;
 
+int32 CChannel::channelsThatNeedService = 0;
+
 void
 CChannel::InitChannels()
 {
@@ -59,7 +61,9 @@ void CChannel::SetDefault()
 		
 	Position[0] = 0.0f; Position[1] = 0.0f; Position[2] = 0.0f;
 	Distances[0] = 0.0f; Distances[1] = FLT_MAX;
-	LoopCount  = 1;
+
+	LoopCount = 1;
+	LastProcessedOffset = UINT32_MAX;
 	LoopPoints[0] = 0; LoopPoints[1] = -1;
 	
 	Frequency = MAX_FREQ;
@@ -67,6 +71,10 @@ void CChannel::SetDefault()
 
 void CChannel::Reset()
 {
+	// Here is safe because ctor don't call this
+	if (LoopCount > 1)
+		channelsThatNeedService--;
+
 	ClearBuffer();
 	SetDefault();
 }
@@ -165,10 +173,51 @@ void CChannel::SetCurrentFreq(uint32 freq)
 	SetPitch(ALfloat(freq) / Frequency);
 }
 
-void CChannel::SetLoopCount(int32 loopCount) // fake. TODO:
+void CChannel::SetLoopCount(int32 count)
 {
 	if ( !HasSource() ) return;
-	alSourcei(alSources[id], AL_LOOPING, loopCount == 1 ? AL_FALSE : AL_TRUE);
+
+	// 0: loop indefinitely, 1: play one time, 2: play two times etc...
+	// only > 1 needs manual processing
+
+	if (LoopCount > 1 && count < 2)
+		channelsThatNeedService--;
+	else if (LoopCount < 2 && count > 1)
+		channelsThatNeedService++;
+
+	alSourcei(alSources[id], AL_LOOPING, count == 1 ? AL_FALSE : AL_TRUE);
+	LoopCount = count;
+}
+
+bool CChannel::Update()
+{
+	if (!HasSource()) return false;
+	if (LoopCount < 2) return false;
+
+	ALint state;
+	alGetSourcei(alSources[id], AL_SOURCE_STATE, &state);
+	if (state == AL_STOPPED) {
+		debug("Looping channels(%d in this case) shouldn't report AL_STOPPED, but nvm\n", id);
+		SetLoopCount(1);
+		return true;
+	}
+
+	assert(channelsThatNeedService > 0 && "Ref counting is broken");
+
+	ALint offset;
+	alGetSourcei(alSources[id], AL_SAMPLE_OFFSET, &offset);
+
+	// Rewound
+	if (offset < LastProcessedOffset) {
+		LoopCount--;
+		if (LoopCount == 1) {
+			// Playing last tune...
+			channelsThatNeedService--;
+			alSourcei(alSources[id], AL_LOOPING, AL_FALSE);
+		}
+	}
+	LastProcessedOffset = offset;
+	return true;
 }
 
 void CChannel::SetLoopPoints(ALint start, ALint end)
@@ -200,6 +249,7 @@ void CChannel::SetPan(int32 pan)
 void CChannel::ClearBuffer()
 {
 	if ( !HasSource() ) return;
+	alSourcei(alSources[id], AL_LOOPING, AL_FALSE);
 	alSourcei(alSources[id], AL_BUFFER, AL_NONE);
 	Data = nil;
 	DataSize = 0;
-- 
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