Game loop

A repeating program cycle that processes input, updates game state, and presents output. Its timing determines how simulation and display progress during play.

Input handling: The process of receiving and interpreting input from devices, networks, or other software. The loop samples player actions so they can affect the next update.
Main loop: The central repeating control structure that runs an application until it exits. A game loop is a specialized main loop built around simulation and presentation.
Variable timestep: A simulation method that advances by the elapsed time since the previous update. It is a simpler alternative to fixed steps, but variable durations can affect simulation stability.
Input lag: The delay between a user's action and the system's response. Input sampling and update scheduling determine how long actions take to affect play.
Game state: The data representing a game's current conditions, entities, and progress. Each update changes this state, which determines what the game displays.
Event loop: A program structure that waits for and dispatches events to handlers. Event-driven applications may sleep between events rather than update continuously.
Render loop: A repeating cycle dedicated to producing and presenting visual frames. Some engines run rendering independently from the game-state update cycle.
Latency (engineering): The delay between an event and its resulting effect in a system. Work queued within the cycle adds delay between input and visible output.
Game physics: The rules and calculations used to simulate motion, forces, and collisions in a game. Physics calculations commonly run during the loop's simulation step.
Delta time: The elapsed time between successive updates or rendered frames. Loops use elapsed time to scale movement and other time-dependent changes.

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