Audio: Handle AudioBuffer compatibility

OpenAL buffers are shared between contextes

include/Nazara/Audio/AudioBuffer.hpp

@@ -29,6 +29,8 @@ namespace Nz
 			virtual UInt32 GetSize() const = 0;
 			virtual UInt32 GetSampleRate() const = 0;
 
+			virtual bool IsCompatibleWith(const AudioDevice& device) const = 0;
+
 			virtual bool Reset(AudioFormat format, UInt64 sampleCount, UInt32 sampleRate, const void* samples) = 0;
 
 			AudioBuffer& operator=(const AudioBuffer&) = default;

include/Nazara/Audio/AudioDevice.hpp

@@ -38,6 +38,7 @@ namespace Nz
 			virtual Quaternionf GetListenerRotation() const = 0;
 			virtual Vector3f GetListenerVelocity() const = 0;
 			virtual float GetSpeedOfSound() const = 0;
+			virtual const void* GetSubSystemIdentifier() const = 0;
 
 			virtual bool IsFormatSupported(AudioFormat format) const = 0;
 

include/Nazara/Audio/OpenALBuffer.hpp

@@ -32,6 +32,8 @@ namespace Nz
 			UInt32 GetSize() const override;
 			UInt32 GetSampleRate() const override;
 
+			bool IsCompatibleWith(const AudioDevice& device) const override;
+
 			bool Reset(AudioFormat format, UInt64 sampleCount, UInt32 sampleRate, const void* samples) override;
 
 			OpenALBuffer& operator=(const OpenALBuffer&) = delete;

include/Nazara/Audio/OpenALDevice.hpp

@@ -39,9 +39,10 @@ namespace Nz
 			float GetGlobalVolume() const override;
 			Vector3f GetListenerDirection(Vector3f* up = nullptr) const override;
 			Vector3f GetListenerPosition() const override;
-			Quaternionf GetListenerRotation(Vector3f* up = nullptr) const override;
+			Quaternionf GetListenerRotation() const override;
 			Vector3f GetListenerVelocity() const override;
 			float GetSpeedOfSound() const override;
+			const void* GetSubSystemIdentifier() const override;
 
 			bool IsFormatSupported(AudioFormat format) const override;
 

include/Nazara/Audio/SoundBuffer.hpp

@@ -50,7 +50,7 @@ namespace Nz
 			SoundBuffer(SoundBuffer&&) = delete;
 			~SoundBuffer() = default;
 
-			const std::shared_ptr<AudioBuffer>& GetBuffer(AudioDevice* device);
+			const std::shared_ptr<AudioBuffer>& GetAudioBuffer(AudioDevice* device);
 
 			inline UInt32 GetDuration() const;
 			inline AudioFormat GetFormat() const;

src/Nazara/Audio/OpenALBuffer.cpp

@@ -52,6 +52,12 @@ namespace Nz
 		return SafeCast<UInt32>(sampleRate);
 	}
 
+	bool OpenALBuffer::IsCompatibleWith(const AudioDevice& device) const
+	{
+		// OpenAL buffers are shared among contexts and thus devices
+		return device.GetSubSystemIdentifier() == &m_library;
+	}
+
 	bool OpenALBuffer::Reset(AudioFormat format, UInt64 sampleCount, UInt32 sampleRate, const void* samples)
 	{
 		OpenALDevice& device = GetDevice();

src/Nazara/Audio/OpenALDevice.cpp

@@ -206,6 +206,11 @@ namespace Nz
 		return m_library.alGetFloat(AL_SPEED_OF_SOUND);
 	}
 
+	const void* OpenALDevice::GetSubSystemIdentifier() const
+	{
+		return &m_library;
+	}
+
 	/*!
 	* \brief Checks whether the format is supported by the engine
 	* \return true if it is the case

src/Nazara/Audio/OpenALSource.cpp

@@ -150,7 +150,7 @@ namespace Nz
 	void OpenALSource::QueueBuffer(std::shared_ptr<AudioBuffer> audioBuffer)
 	{
 		NazaraAssert(audioBuffer, "invalid buffer");
-		NazaraAssert(audioBuffer->GetAudioDevice() == GetAudioDevice(), "incompatible buffer");
+		NazaraAssert(audioBuffer->IsCompatibleWith(*GetAudioDevice()), "incompatible buffer");
 
 		std::shared_ptr<OpenALBuffer> newBuffer = std::static_pointer_cast<OpenALBuffer>(std::move(audioBuffer));
 
@@ -185,7 +185,7 @@ namespace Nz
 
 	void OpenALSource::SetBuffer(std::shared_ptr<AudioBuffer> audioBuffer)
 	{
-		NazaraAssert(audioBuffer->GetAudioDevice() == GetAudioDevice(), "incompatible buffer");
+		NazaraAssert(audioBuffer->IsCompatibleWith(*GetAudioDevice()), "incompatible buffer");
 
 		std::shared_ptr<OpenALBuffer> newBuffer = std::static_pointer_cast<OpenALBuffer>(std::move(audioBuffer));
 

src/Nazara/Audio/Sound.cpp

@@ -219,7 +219,7 @@ namespace Nz
 		Stop();
 
 		m_buffer = std::move(buffer);
-		m_source->SetBuffer(m_buffer->GetBuffer(m_source->GetAudioDevice().get()));
+		m_source->SetBuffer(m_buffer->GetAudioBuffer(m_source->GetAudioDevice().get()));
 	}
 
 	/*!

src/Nazara/Audio/SoundBuffer.cpp

@@ -58,14 +58,32 @@ namespace Nz
 		std::memcpy(&m_samples[0], samples, sampleCount * sizeof(Int16));
 	}
 
-	const std::shared_ptr<AudioBuffer>& SoundBuffer::GetBuffer(AudioDevice* device)
+	const std::shared_ptr<AudioBuffer>& SoundBuffer::GetAudioBuffer(AudioDevice* device)
 	{
+		NazaraAssert(device, "invalid device");
+
 		auto it = m_audioBufferByDevice.find(device);
 		if (it == m_audioBufferByDevice.end())
 		{
-			auto audioBuffer = device->CreateBuffer();
-			if (!audioBuffer->Reset(m_format, m_sampleCount, m_sampleRate, m_samples.get()))
-				throw std::runtime_error("failed to initialize audio buffer");
+			// Try to find an existing compatible buffer
+			std::shared_ptr<AudioBuffer> audioBuffer;
+			for (it = m_audioBufferByDevice.begin(); it != m_audioBufferByDevice.end(); ++it)
+			{
+				const auto& entry = it->second;
+				if (entry.audioBuffer->IsCompatibleWith(*device))
+				{
+					audioBuffer = entry.audioBuffer;
+					break;
+				}
+			}
+
+			if (!audioBuffer)
+			{
+				// Create a new buffer
+				audioBuffer = device->CreateBuffer();
+				if (!audioBuffer->Reset(m_format, m_sampleCount, m_sampleRate, m_samples.get()))
+					throw std::runtime_error("failed to initialize audio buffer");
+			}
 
 			it = m_audioBufferByDevice.emplace(device, AudioDeviceEntry{}).first;