Add Tkge::Utilities::GetCurrentExecutablePath() (#25)

* Add Tkge::Utilities::GetCurrentExecutablePath()

* [[nodiscard]]

* linux support

* [[maybe_unused]]

* stupid space

* static_cast

Author: TymianekPL

App/Src/Main.cpp

@@ -2,6 +2,7 @@
 #include <Tkge/Engine.hpp>
 #include <Tkge/Graphics/Drawable.hpp>
 #include <Tkge/Graphics/Shader.hpp>
+#include <Tkge/Utilities.hpp>
 #include <klib/assert.hpp>
 #include <kvf/time.hpp>
 #include <cmath>
@@ -107,12 +108,12 @@ namespace
 	}
 } // namespace
 
-int main([[maybe_unused]] int argc, char** argv)
+int main([[maybe_unused]] int argc, [[maybe_unused]] char** argv)
 {
 	try
 	{
 		KLIB_ASSERT(argc > 0);
-		const auto assets_path = Upfind(*argv, "Assets");
+		const auto assets_path = Upfind(Tkge::Utilities::GetCurrentExecutablePath(), "Assets");
 		Run(assets_path);
 	}
 	catch (const std::exception& e)

Lib/Include/Tkge/Utilities.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <filesystem>
+#include <string>
+
+namespace Tkge
+{
+	class Utilities
+	{
+	  public:
+		~Utilities() = delete;
+		Utilities() = delete;
+		Utilities(const Utilities&) = delete;
+		Utilities(Utilities&) = delete;
+		Utilities& operator=(const Utilities&) = delete;
+		Utilities& operator=(Utilities&) = delete;
+
+		/// <summary>
+		/// Gets the current executable directory.
+		/// </summary>
+		/// <returns>The parent directory of the main module</returns>
+		[[nodiscard]] static std::filesystem::path GetCurrentExecutablePath();
+	};
+} // namespace Tkge

Lib/Src/AssetLoader.cpp

@@ -1,29 +1,15 @@
 #include <Tkge/AssetLoader.hpp>
+#include <Tkge/Utilities.hpp>
 #include <filesystem>
 
-#ifdef _WIN32
-#ifndef WIN32_MEAN_AND_LEAN
-#define WIN32_MEAN_AND_LEAN
-#define _AMD64_
-#endif
-#include <libloaderapi.h>
-#include <minwindef.h>
-#endif
-
 std::vector<std::filesystem::path> Tkge::AssetLoader::GetSearchPaths() const
 {
 	std::vector<std::filesystem::path> paths{};
 
 	paths.emplace_back(".");
 
-#ifdef _WIN32
-	char buffer[MAX_PATH]{};
-	GetModuleFileNameA(nullptr, buffer, MAX_PATH);
-
-	paths.push_back(std::filesystem::path{buffer}.parent_path());
+	paths.push_back(Tkge::Utilities::GetCurrentExecutablePath());
 	paths.push_back(paths.back() / "Assets");
-#else
-#endif
 
 	return paths;
 }

Lib/Src/Utilities.cpp

@@ -0,0 +1,35 @@
+#include <Tkge/Utilities.hpp>
+
+#ifdef _WIN32
+#ifndef WIN32_MEAN_AND_LEAN
+#define WIN32_MEAN_AND_LEAN
+#define _AMD64_
+#endif
+#include <libloaderapi.h>
+#include <minwindef.h>
+#else // defined(_WIN32)
+#include <limits.h>
+#include <unistd.h>
+#endif
+
+std::filesystem::path Tkge::Utilities::GetCurrentExecutablePath()
+{
+	static std::filesystem::path CachePath{}; // can never change throughout the process existance
+	if (!CachePath.empty()) return CachePath;
+
+#ifdef _WIN32
+	char buffer[MAX_PATH]{};
+	DWORD length = GetModuleFileNameA(nullptr, buffer, MAX_PATH);
+	if (length == 0) return {}; // Error case
+	CachePath = std::filesystem::path{std::string(buffer, length)}.parent_path();
+#elif defined(__linux__)
+	char buffer[PATH_MAX]{};
+	ssize_t length = readlink("/proc/self/exe", buffer, PATH_MAX);
+	if (length == -1) return {}; // Error case
+	CachePath = std::filesystem::path{std::string(buffer, static_cast<std::size_t>(length))}.parent_path();
+#else
+	static_assert(false, "Unsupported platform");
+#endif
+
+	return CachePath;
+}