Fixed Timestep Game Loop

Frame-rate independent game loop with physics interpolation and time manipulation.

When to Use This Skill

• Building browser-based games or interactive simulations
• Need consistent physics regardless of monitor refresh rate
• Want smooth rendering with deterministic game logic
• Implementing hitstop, slow-mo, or time manipulation effects

Core Concepts

The key insight is separating physics (fixed timestep) from rendering (variable). An accumulator tracks time debt, running physics at a consistent rate while interpolating between states for smooth visuals.

Frame → Accumulator += delta → While(accumulator >= fixedStep) { physics() } → Render(interpolation)