4 files changed, 117 insertions, 3 deletions

diff --git a/src/crepe/system/AudioSystem.cpp b/src/crepe/system/AudioSystem.cpp
new file mode 100644
index 0000000..b2c1dc6
--- /dev/null
+++ b/src/crepe/system/AudioSystem.cpp
@@ -0,0 +1,63 @@
+#include "AudioSystem.h"
+
+#include "../manager/ComponentManager.h"
+#include "../manager/ResourceManager.h"
+#include "../types.h"
+
+using namespace crepe;
+using namespace std;
+
+void AudioSystem::update() {
+	ComponentManager & component_manager = this->mediator.component_manager;
+	ResourceManager & resource_manager = this->mediator.resource_manager;
+	RefVector<AudioSource> components
+		= component_manager.get_components_by_type<AudioSource>();
+
+	for (AudioSource & component : components) {
+		Sound & resource = resource_manager.get<Sound>(component.source);
+
+		this->diff_update(component, resource);
+
+		this->update_last(component);
+	}
+}
+
+void AudioSystem::diff_update(AudioSource & component, Sound & resource) {
+	SoundContext & context = this->get_context();
+
+	if (component.active != component.last_active) {
+		if (component.active) {
+			component.oneshot_play = component.play_on_awake;
+		} else {
+			context.stop(component.voice);
+			return;
+		}
+	}
+	if (!component.active) return;
+
+	if (component.oneshot_play) {
+		component.voice = context.play(resource);
+		component.oneshot_play = false;
+	}
+	if (component.oneshot_stop) {
+		context.stop(component.voice);
+		component.oneshot_stop = false;
+	}
+	if (component.volume != component.last_volume) {
+		context.set_volume(component.voice, component.volume);
+	}
+	if (component.loop != component.last_loop) {
+		context.set_loop(component.voice, component.loop);
+	}
+}
+
+void AudioSystem::update_last(AudioSource & component) {
+	component.last_active = component.active;
+	component.last_loop = component.loop;
+	component.last_volume = component.volume;
+}
+
+SoundContext & AudioSystem::get_context() {
+	if (this->context == nullptr) this->context = make_unique<SoundContext>();
+	return *this->context.get();
+}
diff --git a/src/crepe/system/AudioSystem.h b/src/crepe/system/AudioSystem.h
new file mode 100644
index 0000000..2ddc443
--- /dev/null
+++ b/src/crepe/system/AudioSystem.h
@@ -0,0 +1,51 @@
+#pragma once
+
+#include "../api/AudioSource.h"
+#include "../facade/Sound.h"
+#include "../facade/SoundContext.h"
+
+#include "System.h"
+
+namespace crepe {
+
+class AudioSystem : public System {
+public:
+	using System::System;
+	void update() override;
+
+private:
+	/**
+	 * \brief Update `last_*` members of \c component
+	 *
+	 * Copies all component properties stored for comparison between AudioSystem::update() calls
+	 *
+	 * \param component AudioSource component to update
+	 */
+	void update_last(AudioSource & component);
+
+	/**
+	 * \brief Compare update component
+	 *
+	 * Compares properties of \c component and \c data, and calls SoundContext functions where
+	 * applicable.
+	 *
+	 * \param component AudioSource component to update
+	 * \param resource Sound instance for AudioSource's Asset
+	 */
+	void diff_update(AudioSource & component, Sound & resource);
+
+protected:
+	/**
+	 * \brief Get SoundContext
+	 *
+	 * SoundContext is retrieved through this function instead of being a direct member of
+	 * AudioSystem to aid with testability.
+	 */
+	virtual SoundContext & get_context();
+
+private:
+	//! SoundContext
+	std::unique_ptr<SoundContext> context = nullptr;
+};
+
+} // namespace crepe
diff --git a/src/crepe/system/CMakeLists.txt b/src/crepe/system/CMakeLists.txt
index 95f6e33..6b2e099 100644
--- a/src/crepe/system/CMakeLists.txt
+++ b/src/crepe/system/CMakeLists.txt
@@ -5,6 +5,7 @@ target_sources(crepe PUBLIC
 	PhysicsSystem.cpp
 	CollisionSystem.cpp
 	RenderSystem.cpp
+	AudioSystem.cpp
 	AnimatorSystem.cpp
 	InputSystem.cpp
 )
@@ -15,6 +16,7 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	PhysicsSystem.h
 	CollisionSystem.h
 	RenderSystem.h
+	AudioSystem.h
 	AnimatorSystem.h
 	InputSystem.h
 )
diff --git a/src/crepe/system/System.cpp b/src/crepe/system/System.cpp
index f68549b..ecc740d 100644
--- a/src/crepe/system/System.cpp
+++ b/src/crepe/system/System.cpp
@@ -1,7 +1,5 @@
-#include "../util/Log.h"
-
 #include "System.h"
 
 using namespace crepe;
 
-System::System(const Mediator & mediator) : mediator(mediator) { dbg_trace(); }
+System::System(const Mediator & mediator) : mediator(mediator) {}