fix: stream stops and dies on underflow

res/scripts/hud.lua

@@ -121,14 +121,7 @@ function on_hud_open()
 
     stream = PCMStream(44100, 1, 16)
     stream:share("test-stream")
-    local bytes = Bytearray(44100 / 8)
-    for i=1,#bytes do
-        local x = math.sin(i * 0.08) * 1 + 0
-        bytes[i] = x
-    end
-    stream:feed(bytes)
-
-    audio.play_stream_2d("test-stream", 2.0, 1.0, "ui")
+    streamid = audio.play_stream_2d("test-stream", 2.0, 1.0, "ui")
 end
 
 function on_hud_render()

src/audio/AL/ALAudio.cpp

@@ -164,9 +164,10 @@ std::unique_ptr<Speaker> ALStream::createSpeaker(bool loop, int channel) {
     for (uint i = 0; i < ALStream::STREAM_BUFFERS; i++) {
         uint free_buffer = al->getFreeBuffer();
         if (!preloadBuffer(free_buffer, loop)) {
-            break;
+            unusedBuffers.push(free_buffer);
+        } else {
+            AL_CHECK(alSourceQueueBuffers(free_source, 1, &free_buffer));
         }
-        AL_CHECK(alSourceQueueBuffers(free_source, 1, &free_buffer));
     }
     return std::make_unique<ALSpeaker>(al, free_source, PRIORITY_HIGH, channel);
 }
@@ -213,11 +214,11 @@ void ALStream::unqueueBuffers(uint alsource) {
 uint ALStream::enqueueBuffers(uint alsource) {
     uint preloaded = 0;
     if (!unusedBuffers.empty()) {
-        uint first_buffer = unusedBuffers.front();
-        if (preloadBuffer(first_buffer, loop)) {
+        uint firstBuffer = unusedBuffers.front();
+        if (preloadBuffer(firstBuffer, loop)) {
             preloaded++;
             unusedBuffers.pop();
-            AL_CHECK(alSourceQueueBuffers(alsource, 1, &first_buffer));
+            AL_CHECK(alSourceQueueBuffers(alsource, 1, &firstBuffer));
         }
     }
     return preloaded;
@@ -227,14 +228,14 @@ void ALStream::update(double delta) {
     if (this->speaker == 0) {
         return;
     }
-    auto p_speaker = audio::get_speaker(this->speaker);
-    if (p_speaker == nullptr) {
+    auto speaker = audio::get_speaker(this->speaker);
+    if (speaker == nullptr) {
         this->speaker = 0;
         return;
     }
-    ALSpeaker* alspeaker = dynamic_cast<ALSpeaker*>(p_speaker);
+    ALSpeaker* alspeaker = dynamic_cast<ALSpeaker*>(speaker);
     assert(alspeaker != nullptr);
-    if (alspeaker->stopped) {
+    if (alspeaker->manuallyStopped) {
         this->speaker = 0;
         return;
     }
@@ -245,11 +246,11 @@ void ALStream::update(double delta) {
     uint preloaded = enqueueBuffers(alsource);
 
     // alspeaker->stopped is assigned to false at ALSpeaker::play(...)
-    if (p_speaker->isStopped() && !alspeaker->stopped) { //TODO: -V560 false-positive?
-        if (preloaded || dynamic_cast<MemoryPCMStream*>(source.get())) {
-            p_speaker->play();
-        } else {
-            p_speaker->stop();
+    if (speaker->isStopped() && !alspeaker->manuallyStopped) { //TODO: -V560 false-positive?
+        if (preloaded) {
+            speaker->play();
+        } else if (isStopOnEnd()){
+            speaker->stop();
         }
     }
 }
@@ -290,6 +291,14 @@ void ALStream::setTime(duration_t time) {
     }
 }
 
+bool ALStream::isStopOnEnd() const {
+    return stopOnEnd;
+}
+
+void ALStream::setStopOnEnd(bool flag) {
+    stopOnEnd = flag;
+}
+
 ALSpeaker::ALSpeaker(ALAudio* al, uint source, int priority, int channel)
     : al(al), priority(priority), channel(channel), source(source) {
 }
@@ -356,7 +365,7 @@ void ALSpeaker::setLoop(bool loop) {
 
 void ALSpeaker::play() {
     paused = false;
-    stopped = false;
+    manuallyStopped = false;
     auto p_channel = get_channel(this->channel);
     AL_CHECK(alSourcef(
         source,
@@ -372,7 +381,7 @@ void ALSpeaker::pause() {
 }
 
 void ALSpeaker::stop() {
-    stopped = true;
+    manuallyStopped = true;
     if (source) {
         AL_CHECK(alSourceStop(source));
 
@@ -436,6 +445,11 @@ int ALSpeaker::getPriority() const {
     return priority;
 }
 
+
+bool ALSpeaker::isManuallyStopped() const {
+    return manuallyStopped;
+}
+
 static bool alc_enumeration_ext = false;
 
 ALAudio::ALAudio(ALCdevice* device, ALCcontext* context)

src/audio/AL/ALAudio.hpp

@@ -58,6 +58,7 @@ namespace audio {
         bool keepSource;
         char buffer[BUFFER_SIZE];
         bool loop = false;
+        bool stopOnEnd = false;
 
         bool preloadBuffer(uint buffer, bool loop);
         void unqueueBuffers(uint alsource);
@@ -80,6 +81,10 @@ namespace audio {
         void setTime(duration_t time) override;
 
         static inline constexpr uint STREAM_BUFFERS = 3;
+
+        bool isStopOnEnd() const override;
+        
+        void setStopOnEnd(bool stopOnEnd) override;
     };
 
     class ALInputDevice : public InputDevice {
@@ -117,7 +122,7 @@ namespace audio {
         float volume = 0.0f;
     public:
         ALStream* stream = nullptr;
-        bool stopped = true;
+        bool manuallyStopped = true;
         bool paused = false;
         uint source;
         duration_t duration = 0.0f;
@@ -157,6 +162,8 @@ namespace audio {
         bool isRelative() const override;
 
         int getPriority() const override;
+
+        bool isManuallyStopped() const override;
     };
 
     class ALAudio : public Backend {

src/audio/NoAudio.hpp

@@ -61,6 +61,13 @@ namespace audio {
 
         void setTime(duration_t time) override {
         }
+
+        bool isStopOnEnd() const override {
+            return false;
+        }
+
+        void setStopOnEnd(bool stopOnEnd) override {
+        }
     };
 
     class NoAudio : public Backend {

src/audio/audio.cpp

@@ -464,8 +464,15 @@ void audio::update(double delta) {
             speaker->update(channel);
         }
         if (speaker->isStopped()) {
-            streams.erase(it->first);
-            it = speakers.erase(it);
+            auto foundStream = streams.find(it->first);
+            if (foundStream == streams.end() ||
+                (!speaker->isManuallyStopped() &&
+                 foundStream->second->isStopOnEnd())) {
+                streams.erase(it->first);
+                it = speakers.erase(it);
+            } else {
+                it++;
+            }
         } else {
             it++;
         }

src/audio/audio.hpp

@@ -221,6 +221,9 @@ namespace audio {
         /// @brief Set playhead to the selected time
         /// @param time selected time
         virtual void setTime(duration_t time) = 0;
+
+        virtual bool isStopOnEnd() const = 0;
+        virtual void setStopOnEnd(bool stopOnEnd) = 0;
     };
 
     /// @brief Sound is an audio asset that supposed to support many
@@ -355,6 +358,8 @@ namespace audio {
         inline bool isStopped() const {
             return getState() == State::stopped;
         }
+
+        virtual bool isManuallyStopped() const = 0;
     };
 
     class Backend {