An updated manifestation of the SkilLib Engine. Began as a fork for a game, but I started that too early.
It's my implementation of an Entity-Component based model. The engine has a collection of "Systems" which are run automatically. These "Systems" are executed every time the engine loops. Some, like WindowSystem, perform basic tasks to keep OpenGL happy. Others, like MovementSystem, will iterate over entities, and will act accordingly to those entities containing the appropriate components. For example, the MovementSystem will alter an entity's Position component data based on information from a Velocity or RotationalVelocity vector.
Entities are merely a dummy storage place for Components. They are capable of storing and releasing Components, but not much else. Components, similarly, are simply storage containers for data. On its own, the collection of data [16, 16, 100, 100, 100, 50, 1, "beachball"] means nothing. Even breaking it down into its parts, [100,100] [16, 16] [100, 0] [1, 1] ["beachball"] doesn't mean anything without knowing what you're looking at. But if we identify these components with a unique identifier, we, like the engine will know exactly what we're looking at. With IDs, 16, 16 100, 100 100, 0 1, 1 "beachball", the engine can tell that we're talking about an object that is 16pixels wide by 16 pixels wide, with initial position of (100, 100). It also sees that we are moving at a velocity of 100px/s at an angle of 0 radians from the x axis and is rotating clockwise at 1 radian per second. Finally, we see that this object is textured to look like a beach ball.