[nostalgia/core] Get building with GLFW (it has a better Conan package than SDL)

src/nostalgia/core/glfw/core.hpp

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2016 - 2021 gary@drinkingtea.net
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include <nostalgia/core/core.hpp>
+
+namespace nostalgia::core {
+
+struct GlfwImplData {
+	class GLFWwindow *window = nullptr;
+	int64_t startTime = 0;
+	bool running = false;
+	event_handler eventHandler = nullptr;
+};
+
+}