10 files changed, 329 insertions, 23 deletions

diff --git a/src/crepe/api/Asset.cpp b/src/crepe/api/Asset.cpp
new file mode 100644
index 0000000..5271cf7
--- /dev/null
+++ b/src/crepe/api/Asset.cpp
@@ -0,0 +1,58 @@
+#include <filesystem>
+#include <stdexcept>
+#include <whereami.h>
+
+#include "Asset.h"
+#include "api/Config.h"
+
+using namespace crepe;
+using namespace std;
+
+Asset::Asset(const string & src) : src(find_asset(src)) { }
+Asset::Asset(const char * src) : src(find_asset(src)) { }
+
+const string & Asset::get_path() const noexcept { return this->src; }
+
+string Asset::find_asset(const string & src) const {
+	auto & cfg = Config::get_instance();
+	auto & root_pattern = cfg.asset.root_pattern;
+
+	// if root_pattern is empty, find_asset must return all paths as-is
+	if (root_pattern.empty()) return src;
+
+	// absolute paths do not need to be resolved, only canonicalized
+	filesystem::path path = src;
+	if (path.is_absolute())
+		return filesystem::canonical(path);
+
+	// find directory matching root_pattern
+	filesystem::path root = this->whereami();
+	while (1) {
+		if (filesystem::exists(root / root_pattern))
+			break;
+		if (!root.has_parent_path())
+			throw runtime_error(format("Asset: Cannot find root pattern ({})", root_pattern));
+		root = root.parent_path();
+	}
+
+	// join path to root (base directory) and canonicalize
+	return filesystem::canonical(root / path);
+}
+
+string Asset::whereami() const noexcept {
+	string path;
+	size_t path_length = wai_getExecutablePath(NULL, 0, NULL);
+	path.resize(path_length + 1); // wai writes null byte
+	wai_getExecutablePath(path.data(), path_length, NULL);
+	path.resize(path_length);
+	return path;
+}
+
+bool Asset::operator==(const Asset & other) const noexcept {
+	return this->src == other.src;
+}
+
+size_t std::hash<const Asset>::operator()(const Asset & asset) const noexcept {
+	return std::hash<string>{}(asset.get_path());
+};
+
diff --git a/src/crepe/api/Asset.h b/src/crepe/api/Asset.h
new file mode 100644
index 0000000..05dccba
--- /dev/null
+++ b/src/crepe/api/Asset.h
@@ -0,0 +1,60 @@
+#pragma once
+
+#include <string>
+#include <unordered_map>
+
+namespace crepe {
+
+/**
+ * \brief Asset location helper
+ *
+ * This class is used to locate game asset files, and should *always* be used
+ * instead of reading file paths directly.
+ */
+class Asset {
+public:
+	/**
+	 * \param src  Unique identifier to asset
+	 */
+	Asset(const std::string & src);
+	/**
+	 * \param src  Unique identifier to asset
+	 */
+	Asset(const char * src);
+
+public:
+	/**
+	 * \brief Get the path to this asset
+	 * \return path to this asset
+	 */
+	const std::string & get_path() const noexcept;
+
+	/**
+	 * \brief Comparison operator
+	 * \param other Possibly different instance of \c Asset to test equality against
+	 * \return True if \c this and \c other are equal
+	 */
+	bool operator == (const Asset & other) const noexcept;
+
+private:
+	//! path to asset
+	const std::string src;
+
+private:
+	std::string find_asset(const std::string & src) const;
+	/**
+	 * \returns The path to the current executable
+	 */
+	std::string whereami() const noexcept;
+};
+
+} // namespace crepe
+
+namespace std {
+
+template<> struct hash<const crepe::Asset> {
+	size_t operator()(const crepe::Asset & asset) const noexcept;
+};
+
+}
+
diff --git a/src/crepe/api/AssetManager.cpp b/src/crepe/api/AssetManager.cpp
deleted file mode 100644
index 3925758..0000000
--- a/src/crepe/api/AssetManager.cpp
+++ /dev/null
@@ -1,17 +0,0 @@
-#include "util/Log.h"
-
-#include "AssetManager.h"
-
-using namespace crepe;
-
-AssetManager & AssetManager::get_instance() {
-	static AssetManager instance;
-	return instance;
-}
-
-AssetManager::~AssetManager() {
-	dbg_trace();
-	this->asset_cache.clear();
-}
-
-AssetManager::AssetManager() { dbg_trace(); }
diff --git a/src/crepe/api/AudioSource.cpp b/src/crepe/api/AudioSource.cpp
new file mode 100644
index 0000000..4baac9a
--- /dev/null
+++ b/src/crepe/api/AudioSource.cpp
@@ -0,0 +1,20 @@
+#include "AudioSource.h"
+
+using namespace crepe;
+using namespace std;
+
+AudioSource::AudioSource(game_object_id_t id, const Asset & src) :
+	Component(id),
+	source(src)
+{ }
+
+void AudioSource::play(bool looping) {
+	this->loop = looping;
+	this->playing = true;
+}
+
+void AudioSource::stop() {
+	this->playing = false;
+	this->rewind = true;
+}
+
diff --git a/src/crepe/api/AudioSource.h b/src/crepe/api/AudioSource.h
new file mode 100644
index 0000000..1264790
--- /dev/null
+++ b/src/crepe/api/AudioSource.h
@@ -0,0 +1,60 @@
+#pragma once
+
+#include "../Component.h"
+#include "../types.h"
+
+#include "Asset.h"
+
+namespace crepe {
+
+class AudioSystem;
+
+//! Audio source component
+class AudioSource : public Component {
+	//! AudioSource components are handled by AudioSystem
+	friend class AudioSystem;
+
+protected:
+	AudioSource(game_object_id_t id, const Asset & source);
+	//! Only ComponentManager can create components
+	friend class ComponentManager;
+public:
+	// But std::unique_ptr needs to be able to destoy this component again
+	virtual ~AudioSource() = default;
+
+public:
+	//! Start or resume this audio source
+	void play(bool looping = false);
+	//! Stop this audio source
+	void stop();
+
+public:
+	//! Play when this component becomes active
+	bool play_on_awake = false;
+	//! Repeat the current audio clip during playback
+	bool loop = false;
+	//! Normalized volume (0.0 - 1.0)
+	float volume = 1.0;
+
+private:
+	//! This audio source's clip
+	const Asset source;
+
+	//! If this source is playing audio
+	bool playing = false;
+	//! Rewind the sample location
+	bool rewind = false;
+
+private:
+	//! Value of \c active after last system update
+	bool last_active = false;
+	//! Value of \c playing after last system update
+	bool last_playing = false;
+	//! Value of \c volume after last system update
+	float last_volume = 1.0;
+	//! Value of \c loop after last system update
+	bool last_loop = false;
+};
+
+} // namespace crepe
+
diff --git a/src/crepe/api/CMakeLists.txt b/src/crepe/api/CMakeLists.txt
index f9b370f..cca0e8b 100644
--- a/src/crepe/api/CMakeLists.txt
+++ b/src/crepe/api/CMakeLists.txt
@@ -1,5 +1,5 @@
 target_sources(crepe PUBLIC
-	# AudioSource.cpp
+	AudioSource.cpp
 	BehaviorScript.cpp
 	GameObject.cpp
 	Rigidbody.cpp
@@ -7,7 +7,7 @@ target_sources(crepe PUBLIC
 	Transform.cpp
 	Color.cpp
 	Texture.cpp
-	AssetManager.cpp
+	ResourceManager.cpp
 	Sprite.cpp
 	SaveManager.cpp
 	Config.cpp
@@ -19,10 +19,11 @@ target_sources(crepe PUBLIC
 	Animator.cpp
 	LoopManager.cpp
 	LoopTimer.cpp
+	Asset.cpp
 )
 
 target_sources(crepe PUBLIC FILE_SET HEADERS FILES
-	# AudioSource.h
+	AudioSource.h
 	BehaviorScript.h
 	Config.h
 	Script.h
@@ -34,8 +35,7 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Vector2.h
 	Color.h
 	Texture.h 
-	AssetManager.h 
-	AssetManager.hpp
+	ResourceManager.h 
 	SaveManager.h
 	Scene.h
 	Metadata.h
@@ -45,4 +45,5 @@ target_sources(crepe PUBLIC FILE_SET HEADERS FILES
 	Animator.h
 	LoopManager.h
 	LoopTimer.h
+	Asset.h
 )
diff --git a/src/crepe/api/Config.h b/src/crepe/api/Config.h
index 3ab877a..13eabd1 100644
--- a/src/crepe/api/Config.h
+++ b/src/crepe/api/Config.h
@@ -62,6 +62,20 @@ public:
 		 */
 		double gravity = 1;
 	} physics;
+
+	//! Asset loading options
+	struct {
+		/**
+		 * \brief Pattern to match for Asset base directory
+		 *
+		 * All non-absolute paths resolved using \c Asset will be made relative to
+		 * the first parent directory relative to the calling executable where
+		 * appending this pattern results in a path that exists. If this string is
+		 * empty, path resolution is disabled, and Asset will return all paths
+		 * as-is.
+		 */
+		std::string root_pattern = ".crepe-root";
+	} asset;
 };
 
 } // namespace crepe
diff --git a/src/crepe/api/ResourceManager.cpp b/src/crepe/api/ResourceManager.cpp
new file mode 100644
index 0000000..7877ed9
--- /dev/null
+++ b/src/crepe/api/ResourceManager.cpp
@@ -0,0 +1,41 @@
+#include <stdexcept>
+
+#include "util/Log.h"
+
+#include "ResourceManager.h"
+
+using namespace crepe;
+using namespace std;
+
+ResourceManager & ResourceManager::get_instance() {
+	static ResourceManager instance;
+	return instance;
+}
+
+ResourceManager::~ResourceManager() { dbg_trace(); }
+ResourceManager::ResourceManager() { dbg_trace(); }
+
+void ResourceManager::clear() {
+	this->resources.clear();
+}
+
+template <typename T>
+T & ResourceManager::cache(const Asset & asset) {
+	dbg_trace();
+	static_assert(is_base_of<Resource, T>::value, "cache must recieve a derivative class of Resource");
+
+	if (!this->resources.contains(asset))
+		this->resources[asset] = make_unique<T>(asset);
+
+	Resource * resource = this->resources.at(asset).get();
+	T * concrete_resource = dynamic_cast<T *>(resource);
+
+	if (concrete_resource == nullptr)
+		throw runtime_error(format("ResourceManager: mismatch between requested type and actual type of resource ({})", asset.get_path()));
+
+	return *concrete_resource;
+}
+
+#include "../facade/Sound.h"
+template Sound & ResourceManager::cache(const Asset &);
+
diff --git a/src/crepe/api/ResourceManager.h b/src/crepe/api/ResourceManager.h
new file mode 100644
index 0000000..efdd5c5
--- /dev/null
+++ b/src/crepe/api/ResourceManager.h
@@ -0,0 +1,69 @@
+#pragma once
+
+#include <memory>
+#include <unordered_map>
+
+#include "Asset.h"
+#include "Resource.h"
+
+namespace crepe {
+
+class Sound;
+
+/**
+ * \brief The ResourceManager is responsible for storing and managing assets over
+ * multiple scenes.
+ * 
+ * The ResourceManager ensures that assets are loaded once and can be accessed
+ * across different scenes. It caches assets to avoid reloading them every time
+ * a scene is loaded. Assets are retained in memory until the ResourceManager is
+ * destroyed, at which point the cached assets are cleared.
+ */
+class ResourceManager {
+
+private:
+	//! A cache that holds all the assets, accessible by their file path, over multiple scenes.
+	std::unordered_map<const Asset, std::unique_ptr<Resource>> resources;
+
+private:
+	ResourceManager(); // dbg_trace
+	virtual ~ResourceManager(); // dbg_trace
+
+	ResourceManager(const ResourceManager &) = delete;
+	ResourceManager(ResourceManager &&) = delete;
+	ResourceManager & operator=(const ResourceManager &) = delete;
+	ResourceManager & operator=(ResourceManager &&) = delete;
+
+public:
+	/**
+	 * \brief Retrieves the singleton instance of the ResourceManager.
+	 *
+	 * \return A reference to the single instance of the ResourceManager.
+	 */
+	static ResourceManager & get_instance();
+
+public:
+	/**
+	 * \brief Caches an asset by loading it from the given file path.
+	 *
+	 * \param file_path The path to the asset file to load.
+	 * \param reload If true, the asset will be reloaded from the file, even if
+	 * it is already cached.
+	 * \tparam T The type of asset to cache (e.g., texture, sound, etc.).
+	 * 
+	 * \return A reference to the resource
+	 * 
+	 * This template function caches the asset at the given file path. If the
+	 * asset is already cached, the existing instance will be returned.
+	 * Otherwise, the concrete resource will be instantiated and added to the
+	 * cache.
+	 */
+	template <typename T>
+	T & cache(const Asset & asset);
+
+	//! Clear the resource cache
+	void clear();
+};
+
+} // namespace crepe
+
diff --git a/src/crepe/api/Texture.cpp b/src/crepe/api/Texture.cpp
index de0d0ea..6a1e4d8 100644
--- a/src/crepe/api/Texture.cpp
+++ b/src/crepe/api/Texture.cpp
@@ -26,7 +26,7 @@ Texture::~Texture() {
 
 void Texture::load(unique_ptr<Asset> res) {
 	SDLContext & ctx = SDLContext::get_instance();
-	this->texture = std::move(ctx.texture_from_path(res->get_canonical()));
+	this->texture = std::move(ctx.texture_from_path(res->get_path()));
 }
 
 int Texture::get_width() const {