How does the game run?

Main game loop

Like most games, the game works by running a loop, simplified below (the real code can be found in main.cpp).

while (game.running()){
   game.handle_events();   // Get keyboard and mouse inputs
   game.update();          // Update objects and handle collisions
   game.render();          // Draw the objects to the screen
}

Currently, the frame rate is fixed at 30 FPS, as is the window size, but this may be changed in the future.

Entity-Component-System

The game uses an Entity-Component-System (ECS), for handling objects. In it, Entities (objects, players, enemies, anything really) contain Components, which define how these entities respond to their environment and are updated (“system”). For example, the Transform component defines their position and speed, while the component Collider defines how to handle their collisions.

Entites are stored in Manager classes, which handle their updating and rendering (rendering layers can be fine-tuned by giving the Entities groups, by calling Entity::add_group).

Game.hpp and Game.cpp

The Game defines the main class that groups the Game’s main variables and functionalities, such as the window, camera position, and methods for handling events, updating and rendering. It also includes the class Game::AssetManager used for managing the games assets (sprites and fonts).

While the Game.hpp header is mostly generic and could be used in other games, the Game.cpp implementation is not, and should be changed according to your game.

Making YOUR game!

If you want to use this engine for your game, you can always add new components and entites to the existing ones! You’ll need to update the Game.cpp implementation to match your game.

If you want to create new mouse controllers (Components used for controlling entities using the mouse) special attention must be given: See :ref:`custom_controllers_doc`.