Introduction

Frond is a library of runtime game mechanics - composable primitives for game behavior.

What Frond Is

• Runtime primitives - per-frame behavior, queries, state
• Building blocks - not a framework
• Engine agnostic - works with Bevy, macroquad, or no engine
• Kinematic-first for predictable game feel

What Frond Isn't

• Not a game engine
• Not a framework that dictates structure
• Not physics simulation (use Rapier for that)
• Not procgen (see Resin for that)

Primitives

Primitive	Purpose
State Machines	Movement, AI, animation, gameplay states
Timing	Cooldowns, coyote time, input buffering
Pathfinding	A*, flow fields, nav mesh queries
Spatial	Quadtrees, BVH, spatial hashing
Controllers	Kinematic character and camera math

Scope

Frond = Runtime mechanics (runs every frame) Resin = Generation (computation graphs, lazy eval)

The split: Resin generates, Frond runs.

Philosophy

1. Building blocks, not frameworks - You compose primitives
2. Kinematic over dynamic - Code-driven movement feels better
3. Hot-reloadable feel - Logic in Rust, parameters in config
4. State machines for behavior - Explicit transitions, not implicit

See Philosophy for the full design philosophy.