[Engine] Adding entity/component system

3 files changed, 135 insertions, 0 deletions

diff --git a/yage/engine/engine.cpp b/yage/engine/engine.cpp
new file mode 100644
index 00000000..3918e7e9
--- /dev/null
+++ b/yage/engine/engine.cpp
@@ -0,0 +1,52 @@
+/** ---------------------------------------------------------------------------
+ * @file: engine.cpp
+ *
+ * Copyright (c) 2017 Yann Herklotz Grave <ymherklotz@gmail.com>
+ * MIT License, see LICENSE file for more details.
+ * ----------------------------------------------------------------------------
+ */
+
+#include "engine.h"
+
+#include "../core/window.h"
+
+namespace yage
+{
+
+void Engine::mainLoop()
+{
+    Window window;
+
+    window.create("Game Engine", 800, 640);
+
+    while(!window.shouldClose()) {
+        window.clearBuffer();
+
+        update();
+
+        window.swapBuffer();
+    }
+}
+
+void Engine::update()
+{
+    const double dt = 1.0 / 60.0;
+
+    for(auto &&system : systems_) {
+        system->update(dt);
+    }
+}
+
+void Engine::addSystem(System *system)
+{
+    systems_.push_back(system);
+}
+
+Engine &Engine::instance()
+{
+    static Engine engine_instance;
+
+    return engine_instance;
+}
+
+} // namespace yage
diff --git a/yage/engine/engine.h b/yage/engine/engine.h
new file mode 100644
index 00000000..dabe5596
--- /dev/null
+++ b/yage/engine/engine.h
@@ -0,0 +1,44 @@
+/** ---------------------------------------------------------------------------
+ * @file: engine.h
+ *
+ * Copyright (c) 2017 Yann Herklotz Grave <ymherklotz@gmail.com>
+ * MIT License, see LICENSE file for more details.
+ * ----------------------------------------------------------------------------
+ */
+
+#ifndef YAGE_CORE_ENGINE_H
+#define YAGE_CORE_ENGINE_H
+
+#include "system.h"
+
+#include <vector>
+
+namespace yage
+{
+
+/// Main engine class that contains a systems, the main loop and the update
+/// function that updates all the systems.
+class Engine
+{
+public:
+    /// Main game loop of the engine.
+    void mainLoop();
+
+    /// Updates the systems.
+    void update();
+
+    /// Adds a system to the engine.
+    void addSystem(System *system);
+
+    /// Returns the instance of the engine, as there is only one instance of the
+    /// engine.
+    static Engine &instance();
+
+private:
+    /// Vector of all the systems in the engine.
+    std::vector<System *> systems_;
+};
+
+} // namespace yage
+
+#endif
diff --git a/yage/engine/system.h b/yage/engine/system.h
new file mode 100644
index 00000000..c63b4733
--- /dev/null
+++ b/yage/engine/system.h
@@ -0,0 +1,39 @@
+/** ---------------------------------------------------------------------------
+ * @file: system.h
+ *
+ * Copyright (c) 2017 Yann Herklotz Grave <ymherklotz@gmail.com>
+ * MIT License, see LICENSE file for more details.
+ * ----------------------------------------------------------------------------
+ */
+
+#ifndef YAGE_ENGINE_SYSTEM_H
+#define YAGE_ENGINE_SYSTEM_H
+
+namespace yage
+{
+
+/**
+ * System interface for the different systems in the engine.
+ */
+class System
+{
+public:
+    /// Virtual destructor to destroy all the objects that implement this
+    /// properly.
+    virtual ~System() = 0;
+
+    /// Initializes the system. Good practice to have this function instead
+    /// using the constructor.
+    virtual void init() = 0;
+
+    /// Updates the system at each interval using the time step.
+    virtual void update(double dt) = 0;
+};
+
+/// Implement the default destructor, but leaving it as purely virtual in the
+/// definition of the abstract class.
+inline yage::System::~System() {}
+
+} // namespace yage
+
+#endif