diff --git a/src/assets/AssetsLoader.cpp b/src/assets/AssetsLoader.cpp
index b1458a7a..7f0eefbb 100644
--- a/src/assets/AssetsLoader.cpp
+++ b/src/assets/AssetsLoader.cpp
@@ -17,7 +17,7 @@ void AssetsLoader::addLoader(int tag, aloader_func func) {
 	loaders[tag] = func;
 }
 
-void AssetsLoader::add(int tag, const std::string filename, const std::string alias) {
+void AssetsLoader::add(int tag, const path filename, const std::string alias) {
 	entries.push(aloader_entry{ tag, filename, alias });
 }
 
@@ -47,8 +47,8 @@ bool AssetsLoader::loadNext() {
 #include "../graphics/Atlas.h"
 #include "../graphics/Font.h"
 
-bool _load_shader(Assets* assets, const std::string& filename, const std::string& name) {
-	Shader* shader = load_shader(filename + ".glslv", filename + ".glslf");
+bool _load_shader(Assets* assets, const path& filename, const std::string& name) {
+	Shader* shader = load_shader(filename.string() + ".glslv", filename.string() + ".glslf");
 	if (shader == nullptr) {
 		std::cerr << "failed to load shader '" << name << "'" << std::endl;
 		return false;
@@ -57,8 +57,8 @@ bool _load_shader(Assets* assets, const std::string& filename, const std::string
 	return true;
 }
 
-bool _load_texture(Assets* assets, const std::string& filename, const std::string& name) {
-	Texture* texture = png::load_texture(filename);
+bool _load_texture(Assets* assets, const path& filename, const std::string& name) {
+	Texture* texture = png::load_texture(filename.string());
 	if (texture == nullptr) {
 		std::cerr << "failed to load texture '" << name << "'" << std::endl;
 		return false;
@@ -67,7 +67,7 @@ bool _load_texture(Assets* assets, const std::string& filename, const std::strin
 	return true;
 }
 
-bool _load_atlas(Assets* assets, const std::string& filename, const std::string& name) {
+bool _load_atlas(Assets* assets, const path& filename, const std::string& name) {
 	AtlasBuilder builder;
 	for (const auto& entry : std::filesystem::directory_iterator(filename)) {
 		std::filesystem::path file = entry.path();
@@ -83,10 +83,10 @@ bool _load_atlas(Assets* assets, const std::string& filename, const std::string&
 	return true;
 }
 
-bool _load_font(Assets* assets, const std::string& filename, const std::string& name) {
+bool _load_font(Assets* assets, const path& filename, const std::string& name) {
 	std::vector<Texture*> pages;
 	for (size_t i = 0; i <= 4; i++) {
-		Texture* texture = png::load_texture(filename + "_" + std::to_string(i) + ".png");
+		Texture* texture = png::load_texture(filename.string() + "_" + std::to_string(i) + ".png");
 		if (texture == nullptr) {
 			std::cerr << "failed to load bitmap font '" << name << "' (missing page " << std::to_string(i) << ")" << std::endl;
 			return false;
diff --git a/src/assets/AssetsLoader.h b/src/assets/AssetsLoader.h
index 7cb4c6e9..cac41923 100644
--- a/src/assets/AssetsLoader.h
+++ b/src/assets/AssetsLoader.h
@@ -14,11 +14,11 @@
 
 class Assets;
 
-typedef std::function<bool(Assets*, const std::string&, const std::string&)> aloader_func;
+typedef std::function<bool(Assets*, const std::filesystem::path&, const std::string&)> aloader_func;
 
 struct aloader_entry {
 	int tag;
-	const std::string filename;
+	const std::filesystem::path filename;
 	const std::string alias;
 };
 
@@ -30,7 +30,7 @@ class AssetsLoader {
 public:
 	AssetsLoader(Assets* assets, std::filesystem::path resdir);
 	void addLoader(int tag, aloader_func func);
-	void add(int tag, const std::string filename, const std::string alias);
+	void add(int tag, const std::filesystem::path filename, const std::string alias);
 
 	bool hasNext() const;
 	bool loadNext();
diff --git a/src/frontend/graphics/Skybox.cpp b/src/frontend/graphics/Skybox.cpp
index 0ff04855..dcee7137 100644
--- a/src/frontend/graphics/Skybox.cpp
+++ b/src/frontend/graphics/Skybox.cpp
@@ -7,6 +7,10 @@
 #include "../../graphics/Mesh.h"
 #include "../../window/Window.h"
 
+#ifndef M_PI
+#define M_PI 3.141592
+#endif // M_PI
+
 using glm::vec3;
 
 Skybox::Skybox(uint size, Shader* shader) : size(size), shader(shader) {