transition to game engine

1 files changed, 76 insertions, 0 deletions

diff --git a/src/gamerun.hpp b/src/gamerun.hpp
new file mode 100644
index 0000000..efe6ed9
--- /dev/null
+++ b/src/gamerun.hpp
@@ -0,0 +1,76 @@
+/**
+ * @file window.hpp
+ * Handles key press for exiting the game.
+ *
+ * Copyright (C) 2019 Clyne Sullivan
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef GAMERUN_HPP_
+#define GAMERUN_HPP_
+
+#include "input.hpp"
+
+#include <entityx/entityx.h>
+
+#include <atomic>
+#include <iostream>
+
+/**
+ * @class GameRunSystem
+ * Listens for a key event to tell the game to exit.
+ */
+class GameRunSystem : public entityx::System<GameRunSystem>,
+	public entityx::Receiver<GameRunSystem> {
+private:
+	std::atomic_bool shouldRunFlag;
+
+public:
+	/**
+	 * Configures the system to wait for the exit event.
+	 */
+	void configure([[maybe_unused]] entityx::EntityManager& entities,
+		entityx::EventManager& events) {
+		shouldRunFlag.store(true);
+
+		events.subscribe<KeyUpEvent>(*this);
+
+		std::cout << "Press escape to exit." << std::endl;
+	}
+
+	// Unused
+	void update([[maybe_unused]] entityx::EntityManager& entities,
+		[[maybe_unused]] entityx::EventManager& events,
+		[[maybe_unused]] entityx::TimeDelta dt) final {}
+
+	/**
+	 * Receiver for key release events, used to listen for game exit key.
+	 */
+	void receive(const KeyUpEvent& kue) {
+		if (kue.sym == SDLK_ESCAPE)
+			shouldRunFlag.store(false);
+	}
+
+	/**
+	 * Checks if the game exit key has been pressed.
+	 * @return True if the game should exit
+	 */
+	inline bool shouldRun(void) const {
+		return shouldRunFlag.load();
+	}
+};
+
+#endif // GAMERUN_HPP_
+