Core: Rewrite plugin system

src/Nazara/Core/PluginLoader.cpp

@@ -0,0 +1,75 @@
+// Copyright (C) 2022 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Core/PluginLoader.hpp>
+#include <Nazara/Core/DynLib.hpp>
+#include <Nazara/Core/Error.hpp>
+#include <stdexcept>
+#include <Nazara/Core/Debug.hpp>
+
+namespace Nz
+{
+	PluginLoader::PluginLoader()
+	{
+		AddSearchDirectory(".");
+		AddSearchDirectory("plugins");
+	}
+
+	void PluginLoader::AddSearchDirectory(const std::filesystem::path& directoryPath)
+	{
+		m_directories.push_back(std::filesystem::absolute(directoryPath));
+	}
+
+	GenericPlugin PluginLoader::Load(const std::filesystem::path& pluginPath, bool activate)
+	{
+		std::filesystem::path path = pluginPath;
+		if (path.extension() != NAZARA_DYNLIB_EXTENSION)
+			path += NAZARA_DYNLIB_EXTENSION;
+
+		bool exists = false;
+		if (!path.is_absolute())
+		{
+			for (const std::filesystem::path& dir : m_directories)
+			{
+				std::filesystem::path testPath = dir / path;
+				if (std::filesystem::exists(testPath))
+				{
+					path = testPath;
+					exists = true;
+					break;
+				}
+			}
+		}
+		else if (std::filesystem::exists(path))
+			exists = true;
+
+		if (!exists)
+			throw std::runtime_error("failed to find plugin file");
+
+		DynLib library;
+		if (!library.Load(path))
+			throw std::runtime_error("failed to load plugin");
+
+		PluginLoadCallback loadFunc = reinterpret_cast<PluginLoadCallback>(library.GetSymbol("PluginLoad"));
+		if (!loadFunc)
+			throw std::runtime_error("failed to load plugin: PluginLoad symbol not found");
+
+		std::unique_ptr<PluginInterface> pluginInterface = std::unique_ptr<PluginInterface>(loadFunc());
+		if (!pluginInterface)
+			throw std::runtime_error("plugin failed to load");
+
+		if (activate && !pluginInterface->Activate())
+			throw std::runtime_error("failed to activate plugin");
+
+		return GenericPlugin(std::move(library), std::move(pluginInterface), activate);
+	}
+
+	void PluginLoader::RemoveSearchDirectory(const std::filesystem::path& directoryPath)
+	{
+		auto it = std::find(m_directories.begin(), m_directories.end(), std::filesystem::absolute(directoryPath));
+		if (it != m_directories.end())
+			m_directories.erase(it);
+	}
+
+}